Studies On Intermittent Liquid-Phase Bulk Polymerization Technique

As thermoplastics polypropylene resin is made from propylene.Polypropylene's processing technique and its properties have beenimproving continuously because of various kinds of new catalystsemployed. In the recent 30 years, polypropylene has been one of the mostimportant general plastics used in many industrial fields.Intermittent liquid-phase bulk polymerization technique was studiedby researchers in China and further developed on the basis of abundantpropylene gas resources in refining complex and refining plants locatedfar away from each other. This process technology has the advantages ofless equipment used, less investments, low costs, low energy consumptionand less "Three Wastes", etc. However, more and more problems havebeen found in using intermittent liquid bulk polymerization to producepolypropylene due to the shortage of propylene resources since 1990's.Among these, higher energy consumption per unit polypropylene, poorgrade qualities and weaker competition abilities in market were the topthree.In this paper, problems found in using intermittent liquid bulkpolymerization to produce propylene were discussed, and the factors,which influenced the quality of polypropylene, were analyzed. A series ofmethods to solve the problems existed in the production of polypropylenewith intermittent liquid bulk polymerization were proposed.Since using intermittent liquid-phase bulk polymerization method isvery important in the production of polypropylene, to decrease the wasteof propylene per unit polypropylene and improve the quality of theproducts become the center of the paper. This involved optimizingprocess technology in producing process. Especially, we discussed how toimprove the propylene refining system with which the output of refiningpropylene was enhanced, and to decrease the harmful impacts to thepolymerization process caused by the impurities in raw propylenematerials. Since the catalysts with high-activities used can enhance thecompetition abilities of the products in the market, fundamentallyupgrade the quality of the products and decrease the cost in productionprocess, special attentions were also paid to these aspects.Polypropylene modification and advanced technology employmentin future is the key of the development of intermittent liquid-phase bulkpolymerization. Progress can only be made on the basis of enhancedproduct quality and lowered costs.Human beings living quality is closely related to the safetysynthesis of polypropylene and environmental protections. In this paper,problems concerning the safety and environment protection techniques inthe process of polypropylene synthesis were discussed;dangers of staticelectricity and how to remove it were mentioned.