Modification of illite with calcium pimelate and its influence on the crystallization and mechanical property of isotactic polypropylene

A novel illite with β-nucleation ability toward iPP has been prepared through decoration the pristine illite with CaHA, i.e. CaHA-illite. The crystallization behavior and mechanical property of the iPP/CaHA-illite composite were studied. For comparison, the composites were also made simply by adding different components simultaneously into iPP matrix during mixing in a mini-extruder. The results show that, due to the opposite nucleation ability of illite and CaHA, the illite inhibits the β crystallization whereas the CaHA promotes the β crystallization of iPP. The CaHA-illite is very efficient for inducing the β crystallization of iPP. Its efficiency is higher than any of the other samples. Due to the high crystallinity and β iPP crystal fraction, the iPP/CaHA-illite exhibits the best mechanical properties with an increase of 36% in tensile modulus, 163% in maximum strain, and 69% in non-notched impact strength. Meanwhile, the tensile strength of pure iPP has been well maintained.