Processing, thermosets bulk molding

Model polyamicdialkylamides were prepared by the reaction of the secondary amines (XX) and (XXI) with the polyisoimide (XVII) in DMAC at room temperature. Unfortunately, the resultant polyamicdialkylamides only exhibited limited softening behavior for processing into bulk specimens. The inability to provide molded specimens prevented the validation of the In Situ Molecular Composite concept. Research is currently being carried out at a number of academic and industrial institutions on new thermoset chemistry, polyamices-ters, and extended chain polyimides. 

Alkyd thermoset compounds are based on unsaturated polyester resins, which are combined with cross-linking monomers, catalysts, reinforcements, lubricants, and fillers. They are similar to TS polyesters, but have lower levels of monomers. They are part of the group that includes the bulk-molding compounds (BMCs) and sheet-molding compounds (SMCs). Their fast molding cycles at low pressure make them easier to process than other TSs by vacuum, compression, transfer, or injection molding. 

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