Development And Production Of Ethylene-Propylene Random Copolymer Specialty For Tubes

PPR tube has become the first choice in hot water conduct industry on account of its eminent mechanical performance, chemical stability, process ability, creep resistance and thermal endurance and pressure endurance performance. Nationalization of raw material is one of the absolutely necessarily conditions in developing hot and cold tube industry. In view of the tremendous market space and developing foreground of PPR for hot and cold tube, it is necessary to make the special resin for PPR tube nationalized so as to meet the demand of market. Currently, Sinopec Beijing Yanshan Company (BYPC) has successfully developed RCP special resin for tubes named PPR4220 in its 40kt/a liquid-gas phase bulk method PP plant.During the research process, we mapped out the property index for the new developed PPR tube material according to the performance characteristics of PPR tube material and designed its microstructure and fixed the research process for producing.For microstructure of PPR tube, the main parameters to be controlled are MW, MWD, ethylene content and ethylene distribution on molecular chain. In the polymerization test, we aim to control the microstructure of final product such as MW, MDW, ethylene content, ethylene sequence distribution and composition distribution etc by adjusting process parameters such as feed flow of each reactor, reactor level, and polymer amount of each reactor, ethylene flow rate and hydrogen flow rate, etc so as to meet the requirement of our expected design data for microstructure of product and make final product have excellent macro-performance to reach the standard of special material for tube. We have solved key impact factors for production by adjusting process conditions and enable to ensure stable operation of the plant during the production of PPR4220.Proper main and assistant anti-oxidation agents for special resin of PPR tube material were chosen to make optimum anti-oxidation system formulation through tests, such as oxidative abduction period, accelerated thermal oxidative aging, machining stability, water-fast extraction, light aging, etc. Structure and performance of PPR tube special material made from random copolymer polypropylene was studied by analytic technology, such as 13C NMR, TREF, DSC, GPC, etc., and compared with import product. It shows up PPR4220 product made by Yanshan has excellent comprehensive performance, all specifications meet technical index and have same quality with same kind of overseas excellent product. Currently Yanshan has realized big scale industrial production of PPR tube material, been in the domestic leading level no matter on technology or market share and been praised by numerous customers.