ATMOSPHERIC PROCESS FOR POLAR OLEFIN COPOLYMERS AND TERPOLYMERS BY SINGLE SITE CATALYSTS

摘要

Synthetic resins are broadly grouped according to properties such as crystalline vs. amorphous, plastic vs elastic, thermoset vs thermoplastic, insulating vs conductive, polar vs nonpolar, etc. Copolymers of ethylene and polar comonomer possesses very useful properties. They are currently manufactured using free radical initiators at elevated temperature and pressure. These plants are very expensive to construct, so there is urgent need for more economical atmospheric process to replace the aging existing plants. Ziegler catalyst is the most versatile and high performance system to polymerize ethylene and α-olefins. However, its group IVB organometallic catalytic species are easily poisoned by σ or π Lewis basic moiety of a polar monomer. Several approaches have been developed to overcome this limitation. They are the use of functional derivative of polar monomer, generate polar functionality by reaction with vinyl groups, or develop new catalysts based on late transition metal complexes. These methods suffer from either being specific to a single type of polar functionality, or low in productivity. The catalyst cost can be prohibitively high as in the case of Pd catalysts. We have developed a general method to polymerize at ambient temperature and pressure any common polar monomer using either group IVB or VIIIB precursor of single-site Ziegler catalyst. The results are presented here.