CRYSTALLIZATION KINETICS OF COMPATIBILIZED BLENDS OF A LIQUID-CRYSTALLINE POLYMER WITH POLYPROPYLENE

Blends of a maleic anhydride-grafted polypropylene (m-PP) and a liquid crystalline polymer (LCP) based on a copolyester of hydroxynapthoic a cid and hydroxybenzoic acid were fabricated. The morphology and isothe rmal and nonisothermal crystallization kinetics behavior of the m-PP c opolymer and m-PP/LCP blends were investigated using polarizing optica l microscopy, depolarized light intensity, and differential scanning c alorimetry. A polarizing optical micrograph revealed that the m-PP is very effective to promote a finer dispersion of the LCP phase in the P P matrix. Consequently, the LCP domains or fibrils acted as potential sites for the spherulite nucleation. The isothermal kinetics measureme nts also indicated that the rate of crystallization is enhanced in the maleated PP/LCP blends which exhibit transcrystallinity. In general, the nonisothermal kinetics results were in good agreement with those o btained from the isothermal kinetics measurements. (C) 1997 John Wiley & Sons, Inc.