Reinforcement of Polypropylene with Polypropylene-Co-Poly(Ethylene-Propylene) Copolymer prepared by Ziegler-Natta catalyst

In this research, the reinforcement of polypropylene (PP) was studied by using the new appropriate method for synthesizing polypropylene-block-poly (ethylene-propylene) copolymer (PP-co-EP), which can be utilized as rubber toughening agent. This copolymer (PP-co-EP) could be synthesized by varying the feed condition and change of feed gas in the batch reactor system by using Ziegler-Natta catalysts system at copolymerization temperature of 10 ℃. The 13C-NMR tested by 21.61 ppm resonance peak indicated the incorporation of ethylene to propylene chains that could build the microstructure of the block copolymer chain. DSC, SEM, and DMA results also confirmed these conclusions. From this circumstance, the morphology of copolymer trapped in PP matrix could be observed and the copolymer Tg would decrease if higher amount of PP-co-EP were increased. It was found from DMA study that PP-co-EP is good for the polypropylene reinforcement at low temperature. Moreover, the PP-co-EP content affected to the crystallinity and morphology of polymer blend. It was found that the crystallinity of polymer decreased when the PP-co-EP content increased, but tougher mechanical properties under low temperature were observed.