Epoxy-novolac

Epoxy novolac resins are produced by glycidation of the low-molecular-weight reaction products of phenol (or cresol) with formaldehyde. Highly cross-linked systems are formed that have superior performance at elevated temperatures. 

Eor more demanding uses at higher temperatures, for example, in aircraft and aerospace and certain electrical and electronic appHcations, multifunctional epoxy resin systems based on epoxy novolac resins and the tetraglycidyl amine of methylenedianiline are used. The tetraglycidyl amine of methylenedianiline is currently the epoxy resin most often used in advance composites. Tetraglycidyl methylenedianiline [28768-32-3] (TGALDA) cured with diamino diphenyl sulfone [80-08-0] (DDS) was the first system to meet the performance requirements of the aerospace industry and is still used extensively. 

Fig. 12. Powder X-ray diffraction pattern for the 002 peak of samples made from epoxy novolac resin (ENR) as indicated. The data sets have been offset sequentially by 0, 500, 1900 and 3200 counts for clarity.

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... 

The substitution of water-borne versions of these primers is increasing as environmental restrictions on the use of organic solvents become stricter. These are generally aqueous emulsions of epoxy novolac or phenolic based resins stabilized by surfactants [34]. Non-ionic surfactants are preferred, as they are non-hygroscopic in the dried primer films. Hygroscopic ionic surfactants could result in excessive water absorption by the primer film in service. 

Specific strength Epoxy-novolac Resin matrix for filament wound motor case... 

A review of epoxy-novolac reaction mechanisms and kinetics is provided by Biernath et al.85 Depending on the structures of the novolac and the epoxy, reactions have been reported to proceed through an nth-order mechanism or an autocatalytic mechanism.88-92... 

Bisphenol A-derived epoxy resins, 10 356 Bisphenol A epoxy novolacs, 10 370 Bisphenol A manufacture, microporous catalysts and, 14 420 Bisphenol A moiety, 10 355-356 Bisphenol A polycarbonate (BPA-PC),... 

Cresex process, l 676t Cresol epoxy novolacs, 10 369 Cresol novolacs, 10 406 Cresols, from propylene, 20 786-787 m-Cresol, 20 268. See also 3-Methylphenol antimicrobial used in cosmetics, 7 831t o-Cresol. See also 2-Methylphenol... 

Epoxy nanocomposites, 10 350, 434 Epoxy novolac resins, 10 367-370, 383, 450 multifunctional, 10 452 Epoxy novolacs, 17 839 1,2-Epoxypentane, butyraldehyde derivative, 4 462... 

Trisphenol epoxy novolacs, 10 371-372 Tristimulus colorimeters, 7 325 Trisubstituted alkene synthesis, 13 653 Trisubstituted silyl group, in silylation, 22 691... 

Dow Chemical Company, Production Description - DEN Epoxy Novolac Resins, form No. 170 - 143B (1967). 

Considering thermodynamics of adhesion, epoxy/novolac epoxy resins play a vital role for bonding applications especially for inhibition of composite propellants. In view of this fact, it is considered worthwhile to discuss the chemistry of epoxy/novolac epoxy resins in this section before we discuss other systems for this purpose. 

From this result on MRS, we expected that a combination of phenolic-resin-based resist and aqueous alkaline developer would lead to etching-type dissolution and non-swelling resist patterns. In this paper, we report on a new non-swelling negative electron beam resist consisting of an epoxy novolac, azide compound and phenolic resin matrix (EAP) and discuss the radiation chemistry of this resist. 

Materials. Epoxy novolac, DEN-431, obtained from Dow Chemical Co. was selected as the epoxy component. A 3,3 -diazidodiphenyl sulfone synthesized in our laboratory (5) was used as the azide compound. Poly(/7-vinyl phenol) obtained from Maruzen Oil Co. was used as the phenolic resin matrix. The coating solvent was cyclohexanone. The developer used in this study was 0.1 N tetramethylammonium hydroxide aqueous solution. 

Vacuum Curing Effect. In the early stage of this work, we investigated a mixture of epoxy novolac and poly(p-vinyl phenol) (EP) to obtain an electron beam sensitive non-swelling resist. Epoxy novolac was chosen as the sensitizing component, because epoxy groups are known to be electron-beam-sensitive substituents (2). However, it is also known that electron beam resists... 

Exposure-induced Reaction Products. Gel permeation chromatograms of EP, MRS, and EAP were measured before and after exposure at 20 /uC/cm2. The results are summerized in Figures 8 to 10. In the case of EP resist, shown in Figure 8, peaks 1, 2, and 3 represent epoxy novolac dimer, trimer, and tetramer, respectively. Peak 4 represents the main component of the poly(p-vinyl phenol) resin and peak 5 indicates the presence of exposure-induced high molecular weight components in the resin. 

The result obtained from EAP is shown in Figure 10, where peak 1 represents the azide compound and epoxy novolac dimer, and peaks 2, 3, and 4 represent epoxy novolac trimer, tetramer, and the main component of poly(p-... 

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