Synergistic effect of styrene and zinc dimethyldithiocarbamate on the properties of high melt strength polypropylene. Issue 1 (23rd September 2015) - He, Ying
Abstract : High melt strength polypropylene was successfully prepared by a reactive extrusion method, in which pure polypropylene without any additives was used as a basic resin; trimethylolpropane triacrylate was used as a grafting monomer, and styrene and zinc dimethyldithiocarbamate (ZDMC) were used as trapping radicals. The synergistic effects of styrene and ZDMC on melt strength and melt flow rate of modified polypropylene were investigated. When the additions of styrene and ZDMC were 3.5 parts by weight per hundred parts of resin (phr) and 0.3 phr, respectively, the melt strength of modified polypropylene (PP5) was about 21 cN, which was much higher than that of modified polypropylene without styrene (PP0, 4.6 cN). Moreover, crystallization behavior and mechanical properties of modified polypropylene were also investigated. The results showed that the melt and crystallization temperatures of modified polypropylene with styrene were higher than those without styrene, and the size of crystal was smaller. Moreover, the mechanical properties of modified polypropylene were greatly improved in the presence of styrene. J. VINYL ADDIT. TECHNOL., 24:13–17, 2018. © 2015 Society of Plastics Engineers