Characterization of Fiberglass-Filled Diallyl Phthalate Plastic Molding Resins and Molded Parts,
MOUND LAB MIAMISBURG OH
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Characterization of diallyl phthalate DAP molding resins was undertaken by differential scanning calorimetry DSC and by combined size exclusion chromatography SEClow angle laser light scattering LALLS in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SECLALLS indicated that the better molding resins have lower M sub wM sub n ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between deltaH sub R and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95 cure was achieved in some as-molded parts, with a post-cure temperature of 165 C being required to complete the cure to 100. Thickness of the parts was a factor, with the thicker parts being 100 cured as molded. The glass transition temperature of the molded parts increased as cure was g completed, to approx. l60-l65 C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100 cure can be achieved only if a post-curing operation is conducted above the transition temperature of the polymer.