Ma. Mcleod et Dg. Baird, The influence of processing variables on the mechanical properties of injection molded pregenerated microcomposites, COMPOS P B, 30(3), 1999, pp. 297-308
This work was concerned with addressing how injection molding process varia
bles affected the final mechanical properties of composite materials based
on poly(ethylene terephthalate) (PET) reinforced with pregenerated thermotr
opic liquid crystalline polymer (TLCP) fibrils, where the TLCP had a higher
melting point than the PET. These composites, referred to as pregenerated
microcomposites, were produced using a two step processing scheme. First, a
novel dual extrusion process was used to spin strands of PET reinforced wi
th continuous lengths of TLCP fibrils. Second, these composite strands were
subsequently chopped into pellets and injection molded below the melt proc
essing temperature of the TLCP but above that of the matrix. This allowed t
he high modulus TLCP fibrils generated in the spinning step to be retained
in the final injection molded samples. The influence of several injection m
olding variables on the final composite properties was examined, including
the injection molding temperature and the type of diluting matrix used. The
se Variables were shown to affect the final mechanical properties of the co
mposites, with the best mechanical properties being achieved using low inje
ction molding temperatures and poly(butylene terephthalate) as the diluting
resin. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.