Synthesis and characterization of side chain liquid crystalline polyacrylates and their effect on the crystallization of polyethylene using as a nucleating agent

The present work was focused on investigating the potential of using side chain liquid crystalline polymers (SCLCP) as nucleating agents for semicrystalline polymers. For this purpose, two vinyl monomers with liquid crystalline properties were designed and prepared. By means of homopolymerization two side chain liquid crystalline polymers having different architectures were synthesized. The monomers and the polymers obtained were characterized by elemental analysis, FTIR and ¹H-NMR measurements. DSC and HS-POM were employed to study the phase-transition temperatures and mesophase textures for the polymers. The thermal stability of the polymers was measured by TGA. The results showed that the polymers were all thermotropic side chain liquid crystalline polymers with wide liquid crystalline phase temperature range and excellent thermal stability. The effect of one of the SCLCPs used as a nucleating agent in the crystallization of high density polyethylene (HDPE) was investigated by DSC and HS-POM. The results indicated that SCLCP could effectively increase the crystallization temperature, crystallization speed and the crystallinity for HDPE. It was found that the synthesized SCLCP could be an effective nucleating agent for HDPE.