Premium
Blends of a chlorinated poly(vinyl chloride) compound and a thermotropic liquid crystalline copolyester: Mechanical properties of squeezed flow films
Author(s) -
Lee BiingLin
Publication year - 1992
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760321508
Subject(s) - thermotropic crystal , copolyester , materials science , vinyl chloride , composite material , ultimate tensile strength , chlorinated polyvinyl chloride , polymer blend , acryloyl chloride , hydroxybenzoic acid , liquid crystal , polymer , polyester , polymer chemistry , polyvinyl chloride , organic chemistry , liquid crystalline , copolymer , chemistry , optoelectronics , acrylate
Abstract The mechanical properties of squeezed flow films were measured on blends of a chlorinated poly(vinyl chloride) (CPVC) compound and a thermotropic liquid crystalline copolyester of p‐hydroxybenzoic acid/poly(ethylene terephthalate) (60/40), hereafter referred to as LCC. CPVC is immiscible with LCC. The most serious and unique problem of liquid crystalline polymers is their tendency to fibrillate when fabricated into films and injection molded parts, primarily because of a high degree of mechanical anisotropy. It has been found that the mechanical anisotropy of LCC and blends could be lessened using nonisothermal squeezing equibiaxial extension flow. The maximum tensile properties of LCC are achieved when processed in the vicinity of 260°C. For blends of CPVC containing LCC, the mechanical properties are dependent on the processing temperature and compositions. Blends with no more than 20 wt% of LCC exhibit significant increases in tensile properties. This is due to the possibility of frozen‐in macroscopic biaxial orientation of LCC in the blends during the nonisothermal squeezing flow. Within the range of processable temperatures, the reinforcement of CPVC due to the incorporation of LCC can be achieved at a temperature below the optimum processing temperature of LCC, although the thermal history of blends never reaches that temperature.