Branched epoxy novolac

Unstable friction of PA is attributed to tribo-oxidation processes, namely processes with formation of peroxide groups at a-carbon atoms. As a result, a branched and partially cross-linked secondary structure is formed on the friction surface. A 3D rigid skeleton formed in materials on the base of polyamide blends with thermosetting pol3miers (phenol, melaminoformalde-hyde, epoxy-novolac block copol3miers and other t3rpes) improves the wear resistance of their compositions compared to PA [102]. 

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

NMR has been utilized to characterize epoxy resins, formulations and cured networks. It has been shown to be useful in determining the level of branching in epoxy resins and isomers distribution in epoxy novolacs (88,89). 

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 ... 

Shih et al. [60] studied the modification of a novolac-type epoxy resin with PDMS to overcome brittleness and poor impact resistance. This kind of resin is typically cured via their epoxy functions. The authors also introduced isocyanate monofunctionalized PDMS. Hence, the common treatment with MDA (4,4 -methylene dianiline) not only cured the resin on the one hand, but also made it possible to form the branched copolymer. Mechanical and thermal analyses showed that an optimum in isocyanate-terminated PDMS content was required to reach good thermal and physical properties and low moisture absorption. 

---