Study On Ziegler-Natta Catalysts Containing Novel Environmental-Friendly Internal Donor And Transparent Polypropylene Of Wide Peak Molecular Weight Distribution

In the development of Ziegler-Natta catalysts,many different types of internal electron donors have been explored and developed.But the phthalates are still the most widely used internal electron donors in industrial polypropylene production.Phthalates are harmful to the human body.Both the European Union and the United States have restricted the use of phthalates in certain plastic products.The environment and health concerns of phthalates have promoted the research and development of new type of non-phthalates internal electron donors.In this paper,using biomass resources,two novel environmental-friendly internal electron donors,tributyl maleopimarate(ID1)and trioctyl maleopimarate(ID2)have been designed and synthesized by different routes.The esters and the intermediates prepared were analyzed by 1H-NMR,FTIR,mass spectrometry and element analysis methods.A series of environmentally-friendly Ziegler-Natta catalyst for the polymerization of propylene was prepared using the synthetic internal electron donor ID1 and ID2.The Ziegler-Natta catalyst was analyzed by particle size,SEM,FTIR and XPS methods.The prepared environment-friendly Ziegler-Natta catalyst was used for propylene suspension polymerization and propylene bulk polymerization,and the hydrogen sensitivity of the catalyst was explored.The polymer was analyzed by GPC,FTIR,13C-NMR,DSC,TG-DTG,et al analysis methods.The film made by the prepared polypropylene was analyzed by light transmittance-haze analysis,polarizing optical microscope analysis and WAXD analysis.Among the environment-friendly Ziegler-Natta catalyst prepared by using the novel bio-derived internal electron donor,a Ziegler-Natta catalyst prepared by tributyl maleopimarate as internal electron donor is used to explore the optimum polymerization conditions and the hydrogen sensitivity of the catalyst.The optimum polymerization conditions:hydrogen pressure 0.1.MPa,reaction temperature 70°C.,reaction time 1 h,co-catalyst/catalyst molar ratio Al/Ti =500,external electron donor/catalyst molar ratio Si/Ti = 10.The catalyst activity was 11.9 kgPP·gCat-1·h-1.The polypropylene Mw=1.74×105,MWD=8.15,polypropylene melting point 164.9?,crystallinity 43.1%,decomposition temperature 420.53 °C.The polypropylene film prepared had a light transmittance of 93.8%and a haze of 5.4%.