Studies and characterization of RESOL/VAc–EHA/HMMM IPN systems in aqueous medium

Abstract

ABSTRACT:Resol was solution-blended with vinyl acetate-2-ethylhexyl acrylate (VAc-EHA) resin in an aqueous medium, in varying weight fractions, with hexamethoxymethylmelamine (HMMM) as a crosslinker and the data were compared with a control. The present work was aimed to obtain an optimum combination of high-temperature resistance by synthesis of an interpenetrating network (IPN) of the resins. The control gave a semi-IPN system, in which the resol crosslinked, while the acrylic did not, whereas the blend, where HMMM was the crosslinker, gave a full-IPN system. FTIR spectra of the blends of resol/VAc-EHA/ HMMM indicated the formation of new stretching, which was generated due to crosslinking reactions among VAc-EHA and the crosslinker HMMM. TGA showed that, with an increase in the VAc-EHA percent in semi-IPNs, the decomposition temperature decreased gradually, whereas in case of full-IPNs, the decomposition temperature increased with increase in the VAc-EHA percent. However, the fullIPNs had a higher decomposition temperature than that of the semi-IPNs, at the same resol/(VAc-EHA) ratio.

Mechanical and dynamic mechanical studies of epoxy/VAc‐EHA/HMMM IPN–jute composite systems

“…The full‐IPN systems have higher T g values than semi‐IPN systems (Table I). This is due to the fact that crosslinking efficiency and the extent of interpenetrating network formation in the epoxy/VAc‐EHA/HMMM blend increases with an increase in VAc‐EHA/HMMM percent 11–13…”

“…This is due to the fact that crosslinking efficiency and the extent of interpenetrating network formation in the epoxy/VAc-EHA/ HMMM blend increases with an increase in VAc-EHA/HMMM percent. [11][12][13] Tan ␦ Figure 6(c) shows the tan ␦ vs temperature curves of epoxy, semi-IPN, and full-IPN systems. Tan ␦ is a damping term that can be related to the impact resistance of a material.…”

Mechanical and dynamic mechanical studies of resol/vinyl acetate‐2‐ethylhexylacrylate/ hexamethoxymethylmelamine interpenetrating network systems

“…Full‐IPN systems have higher T g values than semi‐IPN systems (Tables I and II). This is due to the fact that crosslinking efficiency and the extent of interpenetrating network formation in resol/VAc–EHA/HMMM blend increase with increase in VAc–EHA/HMMM percent 20…”

Carbon dioxide adsorption on nitrogen enriched carbon adsorbents: Experimental, kinetics, isothermal and thermodynamic studies

“…Ltd., India, was used as polymeric precursor. HMMM is methylated melamine-formaldehyde resin and is obtained from methylolation reaction between melamine and formaldehyde followed by methylation with methanol under acidic conditions [24]. Mesoporous silica (MCM-41) having surface area of 450 m 2 /g and average pore diameter of 3.5 nm was purchased from M/s Tianjin Chemist Scientific Ltd., Tianjin, China and was used as hard template.…”