Epoxy resins, additives

They are also used for vulcanization of organosilicon cauchucs, solidifying agents for epoxy resins, additives to pigments, and so on. [715]. 

Thus, the direct reaction between epoxide and anhydride has been found to be very slow, and the anhydride ring must first be opened before reaction can occur. Ring opening can result from reaction with hydroxyl groups present in commercial epoxy resins addition of basic catalysts, such as tertiary amines and carboxylate ions or addition of Lewis acids (not discussed here). Ring opening by... 

Effect of Epoxy Resin Addition on the Moisture Sensitivity of Macro Defect Free Polymer-Cement Composites... 

Promising flexural strengths were obtained when MDF cements were produced with the addition of small amount of diglycidiyl ether of bisphenol A. The strength drop was only 19% after 28-d water storage of MDF cements with 1% epoxy resin addition. 

Chem. Descrip. Tetrabromophthalic anhydride CAS 632-79-1 EINECS/ELINCS 211-185-4 Uses Flame retardant in prod, of unsat. polyester resins and rigid PU polyols cohardener for epoxy resins additive for latex emulsions derivs. used as flame retardants in diverse applic. (adhesives, wire coating, and wool, etc.)... 

Synonyms MN-dimethyl-i,3-propanediamine N,N-dimethyl-i,3-diaminopropane 3-(dimethylamino)-propylamine dimethylamino-propylamine i-amino-3-dimethylaminopropane N,JV-dimethyl-N-(3-aminopropyl)amine 3-(dimethylamine)propylamine N,N-dimethyl-i,3-propylenediamine 3-(N,N-dimethylamino)propylamine 3-aminopropyldimethylamine DMPA Uses intermediate substance in the synthesis of alkylamidopropyldimethylamines/alkylamidobetaines found as an impurity in cosmetic surfactants present in e.g. shampoos hardener of epoxy resins additive in fuel, dyes, pesticides and binding agents in the production of ion-exchangers A... 

The key intermediate, a cyclic hydrogenphosphinate, 9,10-dihydro-9-oxa-lO-phosphaphenanthrene-lO-oxide, has been converted, originally by Japanese manufacturers, to a variety of difunctional polymer intermediates. Addition to itaconic ester produces a dicarboxylic ester commercially used to make thermoplastic polyesters. This technology is discussed below in connection with modified polyester fibers and epoxy resins. Addition of the hydrogen phosphonate to itaconic acid and copolyesterification can be done in a single operation (61). 

The same general comments apply when epoxy resin additions are made to hydroxy acrylic/amino resin combinations. In addition, the presence of epoxy resins in these systems means that the curing temperature must be raised, from 120°C to between 140 and 1S0°C, in order fully to exploit the improvement in performance expected from such modifications. 

TetrabromobisphenolA. TBBPA is the largest volume reactive flame retardant. Its primary use is in epoxy resins (see Epoxyresins) where it is reacted with the bis-glycidyl ether of bisphenol A to produce an epoxy resin having 20—25% bromine. This brominated resin is typically sold as a 80% solution in a solvent. TBBPA is also used in the production of epoxy oligomers which are used as additive flame retardants. 

In addition, boron trifluoride and some of its adducts have widespread appflcation as curing agents for epoxy resins (qv), and in preparing alcohol-soluble phenoflc resins (qv) (41). 

Grade G-11, glass fabric with heat-resistant epoxy resin binder, has properties similar to those of Grade G-10 at room temperature and, in addition, has high retention of flexural strength at elevated temperatures. 

Nickel dialkyldithiocarbamates stabili2e vulcani2ates of epichlorhydrinethylene oxide against heat aging (178). Nickel dibutyldithiocarbamate [56377-13-0] is used as an oxidation inhibitor in synthetic elastomers. Nickel chelates of substituted acetylacetonates are flame retardants for epoxy resins (179). Nickel dicycloalkyldithiophosphinates have been proposed as flame-retardant additives for polystyrene (180—182) (see Flame retardants Heat stabilizers). 

The binder system of a plastic encapsulant consists of an epoxy resin, a hardener or curing agent, and an accelerating catalyst system. The conversion of epoxies from the Hquid (thermoplastic) state to tough, hard, thermoset soHds is accompHshed by the addition of chemically active compounds known as curing agents. Flame retardants (qv), usually in the form of halogens, are added to the epoxy resin backbone because epoxy resins are inherently flammable. 

High purity 4-dodecylphenol is used to produce specialty surfactants by its reaction with ethylene oxide. The low color of high purity 4-dodecylphenol is important in this appHcation from a standpoint of aesthetics. 4-Dodecylphenol is also used to produce phenoHc resins which are used in adhesive appHcations and printing inks. 4-Dodecylphenol is also used as an epoxy curing catalyst where the addition of 4-dodecylphenol accelerates curing of the epoxy resin to a hard, nontacky soHd. 

A variety of thermosetting resins are used in SMC. Polyesters represent the most volume and are available in systems that provide low shrinkage and low surface profile by means of special additives. Class A automotive surface requirements have resulted in the development of sophisticated systems that commercially produce auto body panels that can be taken direcdy from the mold and processed through standard automotive painting systems, without additional surface finishing. Vinyl ester and epoxy resins (qv) are also used in SMC for more stmcturaHy demanding appHcations. 

A variety of materials has been proposed to modify the properties of asphaltic binders to enhance the properties of the mix (112), including fillers and fibers to reinforce the asphalt—aggregate mixture (114), sulfur to strengthen or harden the binder (115,116), polymers (98,117—121), mbber (122), epoxy—resin composites (123), antistripping agents (124), metal complexes (125,126), and lime (127,128). AH of these additives serve to improve the properties of the binder and, ultimately, the properties of the asphalt—aggregate mix. 

Covers for the battery designs in Figures 1 and 2 are typically molded from materials identical to that of the respective case, and vent plugs are frequentiy made of molded polypropylene. Other combinations are possible, eg, containers molded of polyethylene or polypropylene may be mated with covers of high impact mbber for use in industrial batteries. After the cover is fitted over the terminal post, it is sealed onto the case. The cover is heat bonded to the case, if it is plastic it is sealed with an epoxy resin or other adhesive, if it is vulcanized mbber. Vent caps are usually inserted into the cover s acid fiU holes to faciHtate water addition and safety vent gasses, except for nonaccessible maintenance-free or recombinant batteries. In nonaccessible batteries, the vent is fabricated as part of the cover. 

The addition—reaction product of bisphenol A [80-05-07] and glycidyl methacrylate [106-91-2] is a compromise between epoxy and methacrylate resins (245). This BSI—GMA resin polymerizes through a free-radical induced covalent bonding of methacrylate rather than the epoxide reaction of epoxy resins (246). Mineral fillers coated with a silane coupling agent, which bond the powdered inorganic fillers chemically to the resin matrix, are incorporated into BSI—GMA monomer diluted with other methacrylate monomers to make it less viscous (245). A second monomer commonly used to make composites is urethane dimethacrylate [69766-88-7]. 

Specialty Epoxy Resins. In addition to bisphenol, other polyols such as aUphatic glycols and novolaks are used to produce specialty resins. Epoxy resins may also include compounds based on aUphatic, cycloaUphatic, aromatic, and heterocycHc backbones. Glycidylation of active hydrogen-containing stmctures with epichlorohydrin and epoxidation of olefins with peracetic acid remain the important commercial procedures for introducing the oxirane group into various precursors of epoxy resins. 

In recent years, proprietary catalysts for advancement have been incorporated in precataly2ed Hquid resins. Thus only the addition of bisphenol A is needed to produce soHd epoxy resins. Use of the catalysts is claimed to provide resins free from branching which can occur in conventional fusion processes (10). Additionally, use of the catalysts results in rapid chain-extension reactions because of the high amount of heat generated in the processing. 

The higher molecular-weight soHd epoxy resins are used in formulations that usually consist of a resin, hardener, reinforcing filler, pigments, flow control agents, and other modifiers. In addition to using conventional hardeners in these formulations, epoxy resins can also be hardened with other resins, ie, acryhcs or polyesters. 

In addition to electrical uses, epoxy casting resins are utilized in the manufacture of tools, ie, contact and match molds, stretch blocks, vacuum-forrning tools, and foundry patterns, as weU as bench tops and kitchen sinks. Systems consist of a gel-coat formulation designed to form a thin coating over the pattern which provides a perfect reproduction of the pattern detail. This is backed by a heavily filled epoxy system which also incorporates fiber reinforcements to give the tool its strength. For moderate temperature service, a Hquid bisphenol A epoxy resin with an aHphatic amine is used. For higher temperature service, a modified system based on an epoxy phenol novolak and an aromatic diamine hardener may be used. 

Hexahydrophthalic anhydride (Figure 26.10 II) (Mol. Wt. 154) has a melting point of 35-36°C and is soluble in the epoxy resin at room temperature. When 0.5% of a catalyst such as benzyldimethylamine is used the curing times are of the same order as with phthalic anhydride. About 80 phr are required. In addition... 

A hard carbon with high capacity can be made from epoxy novolac resin [12]. The epoxy resins used cost about US 2.50 per pound and give pyrolysis yields between 20 and 30%. However, it is well known that phenolic (or phenol-formaldehyde) resins can be pyrolyzed to give hard carbons with a yield of over 50% [42]. In addition, these resins cost about USSl.OO per pound. Phenolic resins therefore offer significant cost advantages over epoxy resins, so we... 

Flexibilized epoxy resins are important structural adhesives [69]. Liquid functionally terminated nitrile rubbers are excellent flexibilizing agents for epoxy resins. This liquid nitrile rubber can be reacted into the epoxy matrix if it contains carboxylated terminated functionalities or by adding an amine terminated rubber. The main effects produced by addition of liquid nitrile rubber in epoxy formulations is the increase in T-peel strength and in low-temperature lap shear strength, without reducing the elevated temperature lap shear. 

In the narrow sense, bis-maleimide resin means the thermosetting resin eom-posed of the bis-maleimide of methylene dianiline (BMI, bis(4-maleimidophenyl)-methane) and methylene dianiline (MDA, bis(4-aminophenyl)methane) (Fig. 1). Beeause of the addition meehanism, the resin is eured without elimination, whieh is a eharacteristic of this resin. Bis-maleimide resin is used as a thermally stable matrix up to 204°C (400 F) whieh typical epoxy resins may not normally be used. However, in spite of having an imide structure, bis-maleimides are classified as being moderately thermally stable resins. The aliphatic structure of the resin is not stable for long periods above 232°C (450°F.) If a highly aromatic thermally stable thermosetting resin is necessary, acetylene end-capped aromatic imide-based oligomers should be used. 

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