Interacting Blends of Novel Acrylated Poly(Ester-Amide) Resins - I with Methyl Methacrylate Monomer—Part 1
Bisphthalamic acids were prepared by reaction of phthalic anhydride and aliphatic diamines. Novel poly(ester-amide)s (PEAs) were prepared by reaction of epoxy resin with bisphthalamic acids. Acrylation of PEAs were carried out using acryloyl chloride; products are called acrylated poly(ester-amide)s (APEAs). Elemental analysis, Number average molecular weight and IR spectra recorded for both PEAs and APEAs. Blending of APEAs was carried out with methyl methacrylate monomer. Curing of APEAs-MMA blends were monitored on differential scanning calorimeter. Composites of these blends have been laminated and characterized. Unreinforced cured samples of these blends were analyzed thermogravimetrically.
Novel Flame-Retardant Acrylated Poly(Ester-Amide) Resins Based on Brominated Epoxy
Bisphthalamic acids were prepared by reactions of phthalic anhydride and aromatic diamines. Novel flame-retardant poly(ester-amide) resins (FR-PEAs) were prepared by reactions of brominated epoxy resin (BER) with bisphthalamic acids using a base catalyst. The post reactions of these FR-PEAs were carried out with acryloyl chloride. The resultant products are designated as flame-retardant acrylated poly(ester-amide)s (FR-APEAs). The FR-PEAs and FR-APEAs were characterized by element analysis and number average molecular weight determined by nonaqueous conductometric titration. IR spectra for FR-PEAs and FR-APEAs were also carried out. The curing of these FR-APEAs was monitored on a differential scanning calorimeter (DSC) by using benzoyl peroxide as a catalyst. Glass fiber-reinforced composites of FR-APEAs have been fabricated and their chemical, mechanical, electrical and flame-retardant properties have been evaluated. The unreinforced cured samples of FR-APEAs were analyzed thermogravimetrically.
Evolution of carbide precipitates in Hastelloy N joints during welding and post weld heat treatment
Abstract The effects of welding and post weld heat treatment (PWHT) on the morphology, composition and lattice parameter of the precipitates in the welding joints of Hastelloy N alloy have been investigated. Joint samples were prepared using a gas tungsten arc welding process with ERNiMo-2 fillers, and then solid-solution treated at 1100 °C for 20 min. After welding, eutectic M6C carbides can be observed in the heat affected zones (HAZ) and weld zones (WZ). These eutectic M6C carbides become spheroidized during the following PWHT. The concentration of Si decreases during the transformation from the primary ones to eutectic ones, and then increases during the spheroidizing process. The total concentration of Si + Cr in M6C carbides remains stable during welding and PWHT. At the same time, the heat leads to the outward diffusion of Mo from the M6C carbides, which results in a decrease of the lattice parameter.