Novolac resin, bisphenol

Calculations for a branched advancement synthesis are defined to permit development of well-characterized functionality in the product molecules. In this study, the difunctional epoxy resin monomer used is the diglycidyl ether of bisphenol A, Epon 828, and the multifunctional epoxy phenol novolac resin used is DEN 438. Let ... 

The epoxy novolac resins are synthesized by reaction of phenolic or cresol novolacs with epichlorohydrin in the same fashion as the bisphenol A resins. The number of epoxy groups per molecule is dependent on the number of hydroxyls in the phenol novolac molecule and to the extent to which they are reacted. Complete epoxidation can be accomplished, but this will lead to steric factors, which could limit the useful size of the cured polymer. Thus, selective epoxidation is often practiced.9... 

The repeat unit of bisphenol F epoxy resins (Figure 2.3) or epoxy novolac resin does not significantly increase the epoxy equivalent weight although viscosity and functionality do increase (Helfad, 1996). 

Alternatively, a Novolac resin can be used in place of the bisphenol A or F and this gives rise to an epoxy resin with a higher functionahty in terms of epoxide gronps per molecules, such as formula D. Thus, whilst the bisphenol resins have a maximnm of two epoxides per molecule (theoretical maximum, the actual value is slightly less), the Novolac can have up to about 10, the average chain length of commercial Novolacs. 

Celanese Epi-Rez SU-8 was chosen for these studies. This resin is a polyfunctional epoxy novolac resin (Scheme 2) made from bisphenol-A. It is optically... 

Expanded materials with excellent high-temperature properties are obtained when cresol novolacs are used as hardeners. A typical formulation is based on mixtures of bisphenol A resins and epoxy novolac resins which are cured by cresol novolacs and accelerated by suitable nitrogen-containing agents. 

Chem. Descrip. Epoxidized bisphenol A novolac resin aq. disp. 

Chem. Descrip. Bisphenol F-based epoxy novolac resin Uses Epoxy for high-solids and solv.-free industrial maintenance coatings, chem.-resist. flooring, groufs, and high-temp, adhesives and laminates inc. crosslink dens, and chem. resist, of ambient cured systems Properties Gardner 1 iiq. sp.gr, 1.19 dens. 9.9 Ih/gal vise. 16,000cps EEW 175 100% solids Epotuf 91-263 [Reichhold]... 

Notes. Data is based on novolac and bisphenol-A resins Poisson s Ratio is stated as 0.33 for all grades Heat distortion temperature of unreinforced resins is 130-155"C (266-311 >F)... 

Epoxy-novolac resin n. A two-step resin made by reacting epichlorohydrin with a phenol-formaldehyde condensate. Such resins are also known as thermoplastic, B-stage phenohc resins that are in a state of partial cure. Whereas bisphenol-based epoxy resins contain up to two epoxy groups per molecule, the epoxy novolacs may have seven or more such groups, producing more tightly crossHnked structures in the cured resins. Thus they are stronger and superior in other properties. 

Branched epoxies (37) are prepared by advancing LER with bisphenol A in the presence of epoxy novolac resins. Such compositions exhibit enhanced thermal... 

Others include brominated bisphenol A resins which impart fire resistance, epoxy phenol novolac (EPN) resins, bisphenol F epoxy (DGEBF) resins, epoxy cresol novolac (ECN) resins, cycloaliphatic epoxy resins, and tetraglycidyl-4,4 -diaminodiphenylmethane (TGDDM). 

A = bisphenol A epoxy—aliphatic amine hardener 1 -B = bisphenol A epoxy—aromatic amine hardener 1 -C = bisphenol F epoxy (epoxy novolac) 2-D = polyester resin—chlorendic acid type 2- E = polyester resin—bisphenol A fumarate type 3- F = vinyl ester resin 3-G = vinyl ester novolac resin ... 

DSC has been applied to the determination of Tg in a variety of other polymers including polyimines [1], polyurethanes (PU) [2], Novolac resins [3], polyisoprene, polybutadiene, polychloroprene, nitrile rubber, ethylene-propylene-diene terpolymer, and butyl rubber [4], and bisphenol-A epoxy diacrylate-trimethylolpropane triacrylate [1516]. 

Recently, because high-performance epoxy resin is strict in its requirements, polyfunctional epoxy has been offered in practical fields. In particular, epoxy novolac resin (ENR) is largely used as electronic encapsulation material because of its well-known thermal resistance properties. Because the strucmres of ENR exert a significant influence on the properties of the cured resins, it is necessary to understand their structure-property relationship. Despite various advantages, epoxy needs modifications to overcome some crucial disadvantages like limited solubility in polar solvents, higher cost of bisphenol A-based epoxy and maximum service temperature of only about 100 °C. 

Being a glycidyl ether of a novolac type phenol formaldehyde resin, epoxy phenol novolac resins (Figure 2.39 (a)) are the polymeric multifunctional counterpart of bisphenol F resin. They are supplied as highly viscous through semisolid to solid resins. They are generally prepared by reacting epichlorohydrin with novolac type phenol formaldehyde resins. 

Tg measurements have been performed on many other polymers and copolymers including phenol bark resins [71], PS [72-74], p-nitrobenzene substituted polymethacrylates [75], PC [76], polyimines [77], polyurethanes (PU) [78], Novolac resins [71], polyisoprene, polybutadiene, polychloroprene, nitrile rubber, ethylene-propylene-diene terpolymer and butyl rubber [79], bisphenol-A epoxy diacrylate-trimethylolpropane triacrylate [80], mono and dipolyphosphazenes [81], polyethylene glycol-polylactic acid entrapment polymers [82], polyether nitrile copolymers [83], polyacrylate-polyoxyethylene grafts [84], Novolak type thermosets [71], polyester carbonates [85], polyethylene naphthalene, 2,6, dicarboxylate [86], PET-polyethylene 2,6-naphthalone carboxylate blends [87], a-phenyl substituted aromatic-aliphatic polyamides [88], sodium acrylate-methyl methacrylate multiblock copolymers [89], telechelic sulfonate polyester ionomers [90], aromatic polyamides [91], polyimides [91], 4,4"-bis(4-oxyphenoxy)benzophenone diglycidyl ether - 3,4 epoxycyclohexyl methyl 3,4 epoxy cyclohexane carboxylate blends [92], PET [93], polyhydroxybutyrate [94], polyetherimides [95], macrocyclic aromatic disulfide oligomers [96], acrylics [97], PU urea elastomers [97], glass reinforced epoxy resin composites [98], PVOH [99], polymethyl methacrylate-N-phenyl maleimide, styrene copolymers [100], chiral... 

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