Thermal properties and crystallization kinetics of a new polypropylene-polyamide 6 composite

The crystallization behavior of polypropylene (PP)-polyamide 6 (PA6) composites prepared by melt blending was analyzed by differential scanning calorimetry. Nonisothermal experiments were used to evaluate the effect of lithium chloride (LiCl) on the crystallization process of PP from molten state. The addition of LiCl dramatically modified the non-isothermal crystallization behavior of the PP matrix, the crystallization temperature first increased and then decreased with the increase of LiCl, and crystallization rate and effective activation energy decreased compared with PP-PA composite. The influence of LiCl on the thermal stability of PP-PA6 composites was investigated by thermogravimetry. The results showed the addition of LiCl increased the temperatures at the maximum degradation rate and improved the thermal stability of PP-PA6 composites. In addition, the hydrophilicity of PP was largely improved due to the introduction of hygroscopic PA6 and LiCl. The water contact angle of PP-PA 2.25 decreased from 103 degrees to 65 degrees compared with pure PP.