2. The isocyanate resin.
3.The isocyanate-epoxy resin.
3.1.a.Velocita 'of polimrizzazione.
3.2.Caratteristiche processability '.
3.3a. Deflection temperature
3.3b Thermal resistance and thermo-oxidative
3.3d water absorption and chemical resistance
3.3e Mechanical and thermo-mechanical properties of cured resins also
4. Main Degrees of Isocyanate-Epoxy FPR Resin Developed
4.1 Two-component resins FPR
4.2 Catalysts and Polymerization Specialists Owners FPC
6.Risposte to frequently asked questions.
As part of polymeric materials, crosslinked glassy those arising from in situ polymerization of liquid, or easily liquefiable hot-oligomers and / or other low molecular weight organic compounds chemically reactive multi-functional initiators + and / or catalysts (resin thermosetting) play a key role for decades for a myriad of industrial, civil and military.
Despite the growing environmental and ecological pressures of the last 10-15 years the use of thermoplastic polymer materials (especially in the areas of consumer products such as automotive, rail, industrial vehicles and civil construction) because of their (at least potentially easier) recyclability, thermosetting resins are, thanks to their insolubility infusibility and objective and that poses severe obstacles to the common and convenient procedures for reprocessing hot material still irreplaceable in a variety of skilled employment:
as matrices of structural composites and semi-lightweight structural (inclusive high volume fractions of fiber reinforced high modulus);
materials such as inclusion / encapsulation of electrical / electronic components (especially power devices);
electroinsulating and dielectric materials as for electro-mechanical devices and electrical power at medium and high voltages;
as matrices of composite materials for printed circuits;
as materials for protective coatings (in particular, anti-corrosion) of metal surfaces.
Moreover, they represent an important component of the stones for sharpening, the binder that holds the abrasive, typically aluminum oxide.
Although a full spectrum of chemical-physical and physical-mechanical qualifications in relation to different application requirements the many types of resins to date developed and commercially available, can be considered to satisfy a shortlist of other parameters to discriminate between the two classes "commodity" (both widely heterogeneous chemical point of view) of conventional thermosetting resins (Table 1a) and, respectively, thermosetting resins or special high-performance (Table 1b): glass transition temperature (Tg), bias ( HDT) and continuous use, hydrolytic and chemical resistance, impact resistance and adhesion to metals and minerals; reaction to fire (combustibility / flammability, smoke emission).
This "threshold" of features, beyond which lie the special resins (satisfying the needs of more demanding applications of the types listed above) is summarized as follows:
* HDT and Tg:> 180 - 200 ° C;
* Continuous use temperature:> 160-180 ° C;
* Hydrolytic resistance: essentially unlimited (even hot);
* Chemical resistance: complete indifference chemical and physical, if not (and modestly) to most aggressive chemicals (acids and strong bases hot);
* Impact resistance and adhesion to metals, glass and ceramics:> or = to those of the best conventional epoxy + amine hardeners;
* Fire: least significant inherent flame retardancy (V1-V0 sec. UL 94).
As well known, these performance requirements not only exclude entirely the entire category of unsaturated polyester resins for wider use (whether ortophtalic, isophthalic or bisphenolic), but also the most qualified vinyl-ester resins (epoxy-acrylate) standards, and overall foreclosure for special vinyl ester (epoxy-acrylate multi-functional epoxy-novolacs) and all the conventional epoxy systems and semi-conventional epoxy of bisphenol A and F homopolymerization catalysts with various tertiary amines and halides boron, epoxy resins of bisphenol A and F and epoxy-amine hardeners novolacs with liquids and carbon standards, or with dicyandiamide. Well below the standards of performance are cited other important thermosetting resins such as phenolic and amino resins, "unparalleled" resistance to fire, due to their high brittleness and poor adhesion to metals and inorganic materials in general as well (for various performance deficiencies chemical and / or thermo-mechanical) several other common resins (alkyd, furan, indene-coumarone, etc..) limited use of it to the field of conventional paints.
The requirements of compliance with the parameters defined above restricts the field of thermosetting resins at high temperature performance, thermal-mechanical and chemical properties to a shortlist of products commercially available at high cost, including: a) epoxy systems consisting of standard bisphenol A epoxy resins or epoxy tri-or tetra-functional special amine or anhydride hardeners + special solid (such as, for example, 4,4 '-diamminodifenilsolfone (DDS) or its isomer 3,3'-diamminodifenilsolfone and, respectively, the dianhydride benzophenone-3, 3 ', 4,4'-tetracarbossilica b) condensation and PMR polyimide resins c) standard and modified resins bismaleimmidiche d) polistirilpiridiniche resins, acetylene-functional (or ethinyl-functional), benzociclobuteniche, cyanate- , and N-cyanamide-cianoureido-functional, etc.. .
Table 1a - Conventional Thermosetting Resins: Tg values and costs compared
ortophtalic Tg = 90 ÷ 100 ° C relative cost = 1.0
isophthalic Tg = 115 ÷ 125 ° C relative cost = 1.1 ÷ 1.2
bisphenolic Tg = 110 ÷ 130 ° C relative cost = 1.2 ÷ 1.4
Standard Size = 120 ÷ 130 ° C relative cost = 2.7 ÷ 3.2
multifunctional Tg = 160 ÷ 185 ° C relative cost = 3.5 ÷ 4
+ standard epoxy hardeners
Tg = 120 ÷ 165 ° C relative cost = 2.8 ÷ 3.5
epoxy-novolacs relative cost = 4.8 ÷ 5.5
amino resins (urea-formaldehyde, melamine-formaldehyde, etc.).
Table 1b - Thermosetting Resins for High Performance: Tg values and costs compared
conventional epoxy and epoxy hardeners novolacs + special
Tg = 180 ÷ 280 ° C relative cost = 4.5 ÷ 6.5
multifunctional epoxy resin + hardeners special special
Tg = 260 ÷ 340 ° C relative cost = 8 ÷ 15
Tg> 450 ° C
Tg = 400 ÷ 450 ° C relative cost => 60
Tg = 350 ÷ 400 ° C
acetylene-(or ethinyl-) functional
relative cost = 20 ÷ 50
ISOCYANATE-EPOXY FPR Resins S
Tg = 270 ÷ 300 ° C relative cost = 3.6 ÷ 4.5
ISOCYANATE-EPOXY FPR H resins
Tg = 300 ÷ 320 ° C relative cost = 4.3 ÷ 5.0
For the crosslinked polymeric structures containing 2-oxazolidone or jointly isocyanurate and 2-oxazolidone, from variously catalyzed polymerization of reactive systems consisting of mixtures of isocyanates and epoxy resins + / or isocyanate-functional oligomers, is recognized for many years a substantial interest industry because of their remarkable thermal and chemical stability, and the high temperatures of softening that characterize them (easily and also well above 200 ° C), as well as their cost very competitive in relation to such properties. This is well demonstrated by numerous international patents 80s and 90s of last century, claiming that the preparation and a variety of uses at high temperatures, such as adhesives, matrices of composites, cellular materials for insulation and / or acoustic protective coatings, and dielectric materials electroinsulating, etc..
Unfortunately, the vastness and complexity of the chemistry of isocyanates, epoxides, and especially of mixed systems isocyanate-epoxide inherently difficult to make rapid and reproducible generation of polymeric materials isocyanurate-oxazolidone with the chemical constitution and physical-mechanical properties desired.
In particular, the kinetics of each process is significantly affected by a multitude of very different catalytic agents or co-catalyst (intentionally introduced, present as impurities or by-products), the concentration ratios between the primary reactive species (isocyanates and epoxides) and temperature.
Most varied catalysts have been proposed and studied to date for this particular type of reactive systems: ethyl-methyl-imidazoles and other alkyl-imidazoles, quaternary phosphonium and ammonium salts, alkali metal halides and alkaline earth metals in aprotic polar solvents, complexes of Lewis acids (halides such as boron, aluminum chloride, etc..) with amines, amides or tertiary phosphines, phosphine oxides, etc.. and many catalysts typically used in the production of conventional foam polyisocyanurates as metal carboxylates alkali, alkaline earth metals, of various heavy metals and transition, amino-phenols, and others.
In general, however, the catalyst does not permit ever, or permit only if incurred in percentages then introduced very harmful to the thermo-oxidative stability and chemistry of polymeric materials final hardening time of liquid-epoxy isocyanate hybrid option adequately short (<20-30 minutes) at reasonably low temperatures (typically in the range 20-80 ° C) compatible with most current technologies for the manufacture of finished products or semifinished materials thermosets (including composites).
Many of the most active catalysts among those known and referred to preferentially promote the formation of isocyanurate rather than 2-oxazolidone, resulting in densely crosslinked materials too fragile and unacceptably, or (or in association with this effect) causing at least one of the undesirable side reactions and (3) and (4) of Scheme 3: the first (formation of carbodiimide) due to consumption of isocyanate to generate CO2 within the material (formation of micro-cavities), the second subtracts irreversibly epoxy groups to the formation of the desired groups 2-oxazolidone.
The complex has prevented critical quoted actually still reactive isocyanate-epoxy systems to play the role to which they potentially compete in the qualified field of high performance thermosets. Recently, mass-to-point efficient and selective catalytic systems, coupled with the ability to build and maintain optimal processing protocols through adequate knowledge of the peculiar chemistry of curing and its chemical and physical parameters of control, has created the ' actual availability of a class of thermosetting resins (epoxy resins, isocyanate-FPR) reliable, with surprisingly high performance thermo-mechanical properties, excellent chemical resistance and thermo-oxidative, and simultaneously highly cost competitive against high-performance resins currently available trade (see Tables 1a and 1b).
3. Quick Isocyanate-Epoxy Resins For High Performance FPR
3.1 General Features
ISOCYANATE-epoxy resins and high performance fast curing two-component systems FPR are based on aromatic polyisocyanates family of commercial liquid-diphenylmethane diisocyanate (MDI) [component A], resins (or mixtures of resins) commercial liquid epoxy bi-or Multi-functional type glicidiletere [Component B] and special catalysts and proprietary curing CVT. After mixing the two components A + B ratio typically 70:30 to 60:40 depending on the specific formulation with desired characteristics, the resulting resins are odorless liquid, low viscosity, with a pot-life at room temperature controlled between 10-15 minutes and 6 hours for diversificatissime needs processability. Polymerization converts hard glassy polymer resins with chemically mixed isocyanurate-2-oxazolidone, densely crosslinked, high softening point.
Through the specific catalyst polymerization owners FPC specially developed, the setting time of these resins at temperatures between 25 and 100 ° C is easily altered at the discretion within very broad limits, ranging from hours to minutes, and possibly underestimate up to 30 - 40 seconds at 80-100 ° C. After appropriate post-heat treatment, the resins are converted into glass completely transparent polymer insoluble in color from amber to brown, with a heat distortion temperature between 250 and 320 ° C depending on the wording.
By varying the type and concentration of catalyst and temperature, the hardening time can be adjusted to meet a wide range of processability requirements: those of the fast manufacturing of parts or composite parts molded as R-RIM, S -RIM, RTM, RTM and pultrusion-HS, those procedures or relatively slow lenses of Liquid Injection Molding, Vacuum Infusion Molding or casting forms in open or closed.
These low cost hard resins are further characterized by: 1) exceptional hydrolytic resistance, solvents and aggressive chemicals, 2) good intrinsic resistance to fire, 3) good adhesion to mineral glass, ceramics and metals, 4) low absorption water. In addition to these characteristics, their resistance to exposure to peak temperatures up to 350 ° C and continuous use temperatures up to 200 ° C and more makes them ideal materials as matrix resins for structural composites for construction of parts and components, encapsulation or coating of electrical / electromechanical / electronic, and in all those cases that require a critical combination of high performance, cost competitive and fast processability of the material.
3.2 Characteristics of processability
3.2a Pot-Life and polymerization rate
Pot-life at temperatures up to 50 ° C: perfect latency (stability of the initial viscosity) adjustable from 10-15 minutes to 1-1.5 hours depending on temperature, catalyst type and concentration of FPC.
Gel times at 60-100 ° C: 20 seconds to 2 hours depending on temperature, type and concentration of catalyst.
Vitrification times to 60-100 ° C: 40 seconds to 6 hours depending on temperature, type and concentration of catalyst.
The hardening of the resin must be completed by post-heat treatment: 1 to 6 hours at temperatures from 150 to 240 ° C (typically 1.5 ÷ 2 hours at 180-240 ° C). FPR resins more flexible (to lower Tg final) require post-curing treatments reduced and / or lower temperatures (150 ÷ 180 ° C).
Detailed investigations through mapping the evolution of dynamic-mechanical properties of resins FPR during curing under isothermal and continuous heating treatments at constant speed (processing diagrams CHT) have shown that the cycle of polymerization of these systems consists of two distinct stages, and willing, well-separable: (i) the first stage, which occurs at temperatures up to 120 ° C, provides a glassy material of yellowish and fragile, characterized by a maximum glass transition temperature (Tg1 ° ° ) of 100-120 ° C, still capable of hot forming and soluble in most common polar organic solvents, (ii) the second reaction step, which takes place at temperatures above 140 ° C leads to the final material at high point softening (up to maximum temperature of glass transition (Tg2 ° °) is completely insoluble in coloring from amber to dark amber. With low or moderate concentrations of catalyst, the curing process can therefore be discontinued at the first stage by rapid cooling , the pre-cured resin can be stored, possibly minced hot formed at a later stage and then subjected to heat treatment of complete cure. These features combined make these resins can also be used in technologies of pre-impregnation of glass fiber or carbon (for the manufacture of structural composites and Printed Circuit Boards) in this area, because of their inherently low initial viscosity, these resin systems have compared to epoxy resins, the advantage of not requiring solvents (eliminating the problems related to their subsequent removal) in the process of fiber impregnation. The only cure is required to protect the material partially reacted isocyanate-epoxide by excessive rates of atmospheric moisture during storage.
3.2b processability Microwave
Thanks to their specific mode of action of catalysts, these isocyanate-epoxy resins are ideal for hardened and / or post-treatment hardened by microwave (UHF): in this way of working, the hardening time and post-curing can be minimized to 1 / 4 ÷ 1 / 10 of those cited above for conventional processing conditions. For example, the cycle of 2 hours post-curing at 180-220 ° C rolled S-RIM FPR S-1 resin reinforced with glass fibers may be replaced by a treatment of only 15 minutes under microwave heating with an average temperature of the laminates of the same 225 ° C. Catalysts recently developed specifically for microwave processing (FPC FPC W1 and W2) allow for the preparation and use of compositions of FPR resins with an exciting combination of pot life at room temperature particularly long (up to 4-6 hours) and particularly fast curing under irradiation.
3.2c Rheological properties
Initial viscosity: 100 to 600 cps at 23 ° C depending on the formulation, ie (without thinners of any kind) viscosity of 5-10 times lower than those of liquid epoxy resin systems formulated with different hardeners, and at least 2-4 times lower than those of conventional unsaturated polyester resins and vinyl ester.
Chemoreologia: typical profile of "snap-curing, as required, for example, in RTM and RIM technologies
Thixotropy: the resins can easily be equipped with thixotropic properties, by adding conventional thixotropic agents (eg, 0.5 to 1% by weight of colloidal silica).
3.3 Properties of resins
[B] 3.3a Distortion Temperature
[/ B] Glass transition temperature (Tg ~ HDT). Depending on the formula: Tg resins ISOCYANATE-EPOXY FPR standard S = 250 ÷ 300 ° C (typically 270 ÷ 300 ° C) Tg resins ISOCYANATE-EPOXY FPR special H = 300 ÷ 320 ° C. Relaxation of the resin formulations have reduced glass transition temperature in the range from 180 to 240 ° C, while the Tg of the partially flexible and versions in the range 230 ÷ 270 ° C. For examples of such values, the dynamic-mechanical spectra of Figure 6 shows a value of Tg for the resin standard FPR S-1 of ~ 300 ° C (in a good correlation with the value of ~ 290 ° C resulting from the SDC) , and 265-275 ° C for the resin with low viscosity FPR S-1 LV partially flexibility.
3.3b Thermal Resistance and Thermo-oxidative
The fully reacted resins have excellent thermal stability up to 280 ° C, being able to support current continuous use temperatures> 150 ° C and typically 180 ÷ 200 ° C and peak temperatures up to 350-360 ° C. Their high-temperature aging involves both inert atmosphere and in the air, a simple and slow weight loss, without any damage or microstructural mass of the surface and it remains smooth and shiny. For example, the weight loss of specimens of pure resin is 5 to 6% after 200 hours of continuous exposure in air at 250 ° C, while that of resin reinforced with glass fiber or loaded with inert mineral powders such as flour quartz, calcined kaolin, silica, etc.. (60% by weight of fibers or mineral fillers) varies in the range 2.5 - 2.8% after 2000 hours continuously at 200 ° C even in air. For comparison, Table 4 shows the typical values of weight loss under continuous exposure to high temperatures in air for different epoxy materials for use as bonded. The data in Table 4 show an appreciable superiority FPR H resins even in respect of epoxy with anhydride hardeners, whose thermo-oxidative resistance in the long term is well recognized as optimal, and lower (under the thermosetting polymer) only to that of much more expensive and technically demanding imide resins, cyanate-and acetylene-functional.
The hardened resins have inherent flame retardant properties (as opposed to unsaturated polyester resins, vinyl ester and epoxy-conventional), presenting a fire behavior not much different from that of phenolic resins and imide. Classification according to UL 94 (Underwriters Laboratories) for specimen thickness std. = 3.2 mm
resins also V1 =
resins with addition of common mineral fillers (talc, mica, kaolin) = V0
resins with addition of 10-20% mineral flame retardants special best of V0 =
resins partially brominated = much better V0
3.3d Absorption of Water and Chemical Resistance
In boiling water or in moist air saturated completely hardened resins exhibit water absorption significantly lower than those of the best epoxy hardened current (maximum water absorption equilibrium = 0.9 ÷ 1.0% by weight). The comparative data of Table 5 show the superiority of FPR resins compared to the generality of epoxy materials, and especially to those cured with DDS (the highest Tg) for structural class Aerospace (problems which hydrophilicity, hydration attitudes in moist air and consequent significant loss of stiffness, dimensional instability, etc.. are well known and critically considered in the field of structural composite materials).
With no chemical groupings hydrolytically or otherwise chemically sensitive (such as esters, amides or urethanes), the glass transition temperature and mechanical properties of cured resins are only minimally affected by aging, that is wet in hot water (even in the presence of surfactants). Because of their chemical structure, their resistance to aggressive chemicals is also excellent. Only strong acids and bases and concentrates, can attack and degrade slowly surface resins react fully (in fact capable of withstanding, for example, 12 hours immersion in aqua regia at room temperature, or at least 24 hours in caustic soda 20% hot). The comparative figures of various chemicals and hydrolytic resistance of different aggressiveness reported in Table 6 show a substantial superiority chemistry "Overall resins ISOCYANATE-EPOXY FPR compared to all epoxy materials for use as a consolidated and this superiority is" overwhelming "against unsaturated polyester resins and vinyl-ester if the comparison on the hydrolytic resistance, and above all the bases from which these materials are known to be chemically literally demolished.
3.3e Mechanical and Thermo-Mechanical Properties of Resins Pure completely polymerized
The overall spectrum of their mechanical and thermo-mechanical configure these as excellent matrix resins for structural composites, especially for applications at high temperatures.
4. Main Degrees of Isocyanate-Epoxy FPR Resin Developed
4.1 Two-component resins FPR
Comparing materials put at a relative humidity of 50-55%, flexural properties, tensile and impact at room temperature resins ISOCYANATE-EPOXY FPR are generally equivalent to those of the best unsaturated polyester resins, vinyl ester and epoxy conventional and special "non-impact resistant":
flexural strength at 23 ° C (ASTM D790) = 90 to 110 MPa
flexural modulus at 23 ° C (ASTM D790) = 3 to 4 GPa
A comparison of these values of mechanical properties in bending with the corresponding ranges of variability for different types of epoxy materials for current (shown in Table 7) shows an equivalent rigidity and a strict inferiority average 20% of the tensile strength of FPR compared to epoxy resins [for material conditioned at 23 ° C to dry (in a relative humidity of 50-55%)]. Because of the higher - much higher capacity for water absorption of epoxy resins compared to FPR (see Table 3.3de 5), comparative characterisations on materials to put up along 23 ° C in ambient relative humidity of 95-100% have highlighted the achievement of general equivalence of the resistance to bending and tension between the different epoxy resins for comparison and FPR, and a significant superiority of elastic modulus of the latter compared to the same epoxy reference.
As illustrated in Figure 6a, FPR completely cured resins show better retention of mechanical properties over a very wide temperature range, at least up to about 50 ° C below their glass transition temperature: decrease of 20 to 25% of modulus over the entire temperature range -50 ÷ 200-220 ° C for standard resins (resins FPR S), and over the -50 ÷ 260 ° C for those high heat distortion temperature (FPR H resins). Obviously, decreases proportionally much lower stiffness are exhibited from the same mineral fillers and additives, a fortiori, from reinforced with glass fibers or carbon.
FPR S-1 resin: Resin standard medium viscosity and medium thermal-mechanical properties (HDT> 250 ° C), fire resistance = V1 according to UL 94, transparent, light amber color. Resin for general use and manufacture of composite materials reinforced with standard glass fiber, carbon or Kevlar.
Resin FPR S-1 FG [food grade] (experimental resin): New resin suitable for use in food, fast-curing and performance standards; medium viscosity and medium thermal-mechanical properties (HDT> 250 ° C), resistance Fire = V1 sec. UL 94, transparent, light amber color. Resin for use at high temperatures and high resistance to chemical components and articles in contact with food and drink, this resin system involves the use of special food-grade Catalyst FPC FG-2.
FPR S Resin-2 (experimental resin) resin standard medium viscosity and medium thermal-mechanical properties (HDT> 250 ° C), halogen-free flame retardant (V0, sec. UL 94), translucent, light amber . Resin composite materials standards and general purpose requirements of halogen-free flame retardancy.
FPR S-3 resin: Resin standard medium viscosity and medium thermal-mechanical properties (HDT = 240-250 ° C), brominated flame retardant in part (V0 sec. UL 94), clear, light amber. Resin composite materials std., Applications, electrical / electronic / electromechanical and general applications with higher requirements for fire resistance.
FPR S Resin LV-1: very low viscosity resin and medium-sized thermal-mechanical properties (HDT = 240 ° C), fire resistance = V1 sec. UL 94, transparent, light amber color. Resin suitable for manufacture of composite materials with volume fractions of reinforcement fibers, particularly high, especially for structural composites with high mechanical performance by infiltration of preforms with dense packing of glass fibers, carbon and / or Kevlar ®.
FPR S-3 LV resin: Resin-like FPR S-1 LV, partially brominated flame retardant (V0 sec. UL 94).
FPR H-0 resin: Resin special dark brown to sustained higher viscosity and thermal-mechanical (heat distortion temperature = 300 ° C) and chemical properties, fire resistance = V1-V0 sec. UL 94. Resin for special uses (structural composites for aerospace industry standard for high temperature, high voltage electrical applications, applications in highly aggressive chemical environments).
Resin FPR H-1: Special resin similar to FPR H-0, amber, medium viscosity, high thermal-mechanical (heat distortion temperature> 280 ° C) and chemical properties, fire resistance = V1-V0 sec. UL 94. Resin for special uses (structural composites for aerospace industry standard for high temperatures, medium voltage electrical applications, use in chemically aggressive environments).
FPR Resin H-2 (experimental grade) resin special like FPR H-1, supporting viscosity, halogen-free flame retardant (V0 sec. UL 94).
FPR Resin H-3: Special resin similar to FPR H-1, medium viscosity, partially brominated flame retardant (V0 sec. UL 94).
4.2 Catalysts and Polymerization Specialists Owners FPC
The FPC catalysts are insensitive to moisture, are non-toxic, harmless, non-corrosive and non-flammable, with a guaranteed minimum of one year stability at room temperature when properly stored in closed containers and protected from prolonged exposure to sunlight or sources artificial actinic light (preferably in cans or metal drums or in dark glass containers). Products, "catalyst pure" systems are only available in conjunction with FP Resin System complete. Products, "catalyst concentrate" are available separately from components isocyanate "and" epoxy "system PF Resin System users interested in their own supplies, according to the specifications of liquid isocyanates and epoxy resins for different systems PF Resin System.
Catalyst FPC 1A "pure catalyst. Catalyst Semi rapid hardening std. For all the standard FPR S Resin Clear oily liquid, colorless to straw rapidly soluble in resins at room temperature. Catalyst at low cost, dual-function: fast + hardening accelerator catalyst impregnation of reinforcing fibers in composite materials. Perfect in the manufacture or LIM RTM composites and structural quality standards for motor vehicles, industrial vehicles, parts and various industrial buildings.
Catalyst FPC 1B: "Catalyst pure." Catalyst std. of fast-curing, for the standard FPR Resins S. Clear oily liquid, straw-colored; rapidly soluble in resins at room temperature. Catalyst convenient dual functionality: a catalyst for rapid hardening accelerator + impregnation of reinforcing fibers in composite materials. Ideal for making R-RIM, S-RIM, RTM & HS-RTM, LIM, and in the pultrusion of structural composites for vehicles, industrial vehicles, parts and various industrial buildings.
Catalyst FPC 2A: "Catalyst pure." Catalyst for very rapid hardening, specialized for special FPR H resins, or as a catalyst for rapid low-dose or standard FPR S Resin Clear liquid honey, refractive, yellowish, readily soluble in resins at room temperature. For applications requiring hardened resin with a higher level of thermal performance, thermo-mechanical and chemical: Recommended for high temperature use continuous use in oxidizing conditions and / or strong chemical attack, stress cycles involving wet / dry or hot / cold, etc.. Excellent for achieving electrical insulation for heavy operating conditions.
Catalyst FPC CP-2A: "Catalyst concentrated. Solution master of fast-curing catalyst FPC 2A in a liquid mixture of epoxy resins. Liquid honey Clear, pale yellow; easily miscible with the resin at room temperature. Particularly suitable for precise dosage of catalyst 2A FPC preparations and uses of small batch of resin systems FPR.
Catalyst FPC FG-2: Catalyst pure. " Special fast-curing catalyst, food grade, developed for the system Resin System FPR S-1 FG [food grade]. Liquid honey clear, pale yellow (catalyst experimental).
Catalyst FPC 2B "pure catalyst. Catalyst hardening super-fast, specialized for special FPR H resins, or as a catalyst super-fast or very low dose for the standard FPR S Resin Clear liquid honey, refractive, yellowish, easily soluble in resins at room temperature. For applications requiring resin hardened with an overall spectrum of rewarding performance thermal, thermo-mechanical, chemical and electrical properties, ideal for the manufacture of composite structural parts and components of motor vehicles, industrial vehicles, equipment and various industrial construction, aimed at heavy thermal conditions of labor standards for composite aerospace, electrical insulation for high voltage equipment and incurred operating temperatures.
Catalyst FPC CP-2B "Catalyst concentrated. Solution master of fast-curing catalyst FPC 2B in a liquid mixture of epoxy resins. Liquid honey Clear, pale yellow; easily miscible with the resin at room temperature. Particularly suitable for precise determination of the catalyst FPC 2B preparations and uses of small batch of resin systems FPR.
Catalyst FPC XF NEW! "Catalyst pure." Ultra-fast curing catalyst for all resins and FPR FPR H. St. Low-melting crystalline solid, pale yellow in color. Designed to minimize that further reduce the already low concentration of the catalyst rapidly FPC 2B.
Catalyst FPC W1: "Catalyst pure." Special catalyst for all S & H FPR Resins, long pot life, specializing in microwave accelerated processing. Reflective liquid honey, amber in color; rapidly soluble in resins gently warmed. Imparts to the resins harden the same range of features than the guaranteed Catalyst FPC 2A.
Catalyst FPC W2: "Catalyst pure." Special catalyst for all S & H FPR Resins, long pot life, specialized for processing super-accelerated microwave. Honey-like liquid with high viscosity, refractive, amber, easily soluble in resins gently warmed. Imparts to the resins harden same reward spectrum of thermal, thermo-mechanical, chemical and electrical guaranteed by Catalyst FPC 2B.
5. Riferimenti Generali
F.W. Harris and H.J. Spinelli (eds.), Reactive Oligomers, ACS Symp. Ser., 282, Am. Chem. Soc., Washington DC, 1985.
P.E. Cassidy, Thermally Stable Polymers, Dekker, New York, 1980; J.P. Critchley, C.J. Knight and W.W. Wright, Heat Resistant Polymers, Plenum Press, London, 1983.
F. Parodi, "Step-Growth Polymerization", in The Encyclopedia of Advanced Materials, eds. D. Bloor, R.J. Brook, M.C. Flemings and S. Mahajan, Pergamon (Elsevier Sci. Publ.), Oxford, 1994, vol. 4, pp. 2665-2679.
F. Parodi, "Isocyanate-Derived Polymers", in Comprehensive Polymer Science, vol. 5, eds. G. Eastmond, A. Ledwith, S. Russo and P. Sigwalt, Pergamon Press, Oxford, 1989, chapter 23 (pp. 387-412).
M. Uribe and K.A. Hodd, "The Catalysed Reaction of Isocyanate and Epoxide Groups: A Study using Differential Scanning Calorimetry", Thermochimica Acta, 77, 367-373 (1984); T.I. Kadurina, V.A. Prokopenko and S.I. Omelchenko, "Curing of Epoxy Oligomers by Isocyanates", Polymer, 33, 3858-3864 (1992).
J.B. Enns and J.K. Gillham, "Time-Temperature-Transformation (TTT) Cure Diagram: Modeling the Cure Behavior of Thermosets", J. Appl. Polym. Sci., 28, 2567-2591 (1983); M.T. Aronhime and J.K. Gillham, "Time-Temperature-Transformation (TTT) Cure Diagram of Thermosetting Polymeric Systems", Adv. Polym. Sci., 78, 83-113 (1986); J.K. Gillham and J.B. Enns, "On the Cure and Properties of Thermosetting Polymers using Torsional Braid Analysis", Trends Polym. Sci., 2, 15-25 (1994).
M.T. DeMeuse, J.K. Gillham and F. Parodi, "Evolution of Properties of an Isocyanate/Epoxy Thermosetting System During Cure: Continuous Heating (CHT) and Isothermal Time-Temperature-Transformation (TTT) Cure Diagrams", J. Appl. Polym. Sci., 64, 15-25 (1997).
M.T. DeMeuse, J.K. Gillham and F. Parodi, "Evolution of Properties of a Thermosetting Isocyanate /Epoxy/Glass Fiber Composite Model System with Increasing Conversion", J. Appl. Polym. Sci., 64, 27-38 (1997).
M.T. DeMeuse, F. Parodi, R. Gerbelli and A.C. Johnson, "Microwave Processing of Isocyanate/Epoxy Composites", 39th International SAMPE Symp. (Anaheim, California, USA, April 11-14, 1994), conference proceedings, vol. 1, pp. 13-23.
6. Answers to Frequently Asked Questions
The FPR resins contain plasticisers, solvents and / or volatile organic compounds? The FPR Resin Systems are specifically developed to support very high temperatures (250 - 300 ° C), similar to commercial multifunctional epoxy systems with higher glass transition temperature, for structural, electrical, electronic and electromechanical challenging, with the advantage to be compared to these, much less viscous and very quickly cured. In relation to their primary intended use as materials for high temperatures, FPR resin systems contain no plastic, paint thinner or solvent, nor any volatile organic compound.
These materials can be toughened thermosetting polymer additives with conventional toughening? FPR Resin Systems chemically toughened plastic and can be developed on demand according to specific technical requirements of the buyer, though hardened resins in this family with values of the glass transition temperature below 220 ° C are not recommended. This in order to minimize adverse effects, however toughening agents and plasticizers used against excellent heat resistance, hydrolytic, chemical and fire their own these thermosets. Several toughening agents oligomeric / polymeric use established in the field of epoxy resins can also be used in epoxy-isocyanate systems, with effects
What are the margin of tolerance on the conditions of processing / curing, for example% humidity, temperature, etc.. ? The FPR Resin Systems are much more tolerant of moisture than is commonly expected on the basis of their high content of aromatic isocyanate free starting. For the manufacture of structural composites and castings in the mold quality, pre-vacuum degassing of resins is desirable or even strongly recommended, as it is for all liquid epoxy systems used for the same purposes. Typical requirements for the manufacture of parts and quality parts and composite structural processes through closed molds (R-RIM, S-RIM, RTM, Vacuum Infusion Molding and casting): molds clean and dry, reinforcing fibers and mineral fillers having or pre-dried with hot air or infrared so you have a moisture content less than 0.05% by weight and preferably less than 0.02% (good option microwave or radio frequency drying of glass fiber); transfers resins through pipes clean and dry containers purgaggio resins with nitrogen or air dry (recommended, though not usually necessary).
What are the storage conditions of the components of the FPR Resins, p. es. % moisture, maximum temperature and duration of the products in stock? Epoxy (insensitive to humidity) of at least one year at room temperature (up to 35 ° C) in closed containers. Isocyanate (reactive with water and humidity): typical duration of isocyanates MDI liquid, that is 6 months to maximum 20 ° C in original sealed drums or containers provided partially emptied after purgaggio closed carefully with dry air or nitrogen. Catalyst FPC (moisture insensitive or only weakly hygroscopic): one year at room temperature (up to 35 ° C) in original sealed containers, at least 6 months in milk cans or partially emptied, provided always tightly closed.
The isocyanate-epoxide uncatalyzed mixtures are stable over time? The isocyanate-epoxide mixtures should be prepared in quantities required before their use, and can be stored only for limited periods of time without significant increases spontaneous viscosity. Storage time at room temperature for mixtures suggested uncatalyzed epoxy-isocyanate: 48 hours maximum (typically no more than 36 hours at 20-25 ° C, no more than 12 hours at 30-35 ° C).