Chlorination Modification And Thermal-Oxidative Aging Of High Isotactic Polybutene-1

High isotactic polybutene-1(i-PB-1) was chlorinated by aqueous suspensionmethod. The method was studied in first chapter. Chlorination extent of i-PB-1 wasinfluenced by self characteristic, process conditions and additives. These factors wereinspected in first chapter. Dynamics and inner structures of chlorinated high isotacticpolybutene-1(CPB-1) were researched. Solubility and thermal stability of CPB-1 alsowere researched.Many methods can increase chlorine content of CPB-1,in the process ofchlorinating i-PB-1. These methods contained high melt rate of i-PB-1,chlorinatedtemperature rising and chlorinated time prolonging. High chlorine content of CPB-1was obtained in comparative shorter time through phase-heating method. Initiator canenhance chlorine content of CPB-1 in initial reaction stages. NaCl can reduce chlorinecontent of CPB-1. Rate of aerating Cl₂ and dilute H₂SO₄ didn't influence chlorinecontent of CPB-1.According to spectra of DSC, CPB-1 still contained crystal form of poly-butene-1. According to spectra of DMA, tgδcurves of CPB-1 had tow peaks. Thepeaks were caused by mocular chains ofi-PB-1 and CPB-1.With chlorine content increasing, solubility of CPB-1 improving. When chlorinecontent was up to 60/wt%, CPB-1 almost dissolved overall. With chlorine contentincreasing, intrinsic viscosity of CPB-1 brought down. When chlorine content wasbetween 30 and 60/wt%, thermal degradation temperature rose slowing with chlorinecontent rising. When chlorine content was up to 60/wt%, thermal degradationtemperature rose quickly. Compared to i-PB-l, hardness, density and tensile strength of CPB-1 were higher. Vicat softening point was lower than i-PB-l′sThermal-oxidative aging of i-PB-1 was studied in second chapter. Influence ofdifferent antioxidants on processing and long-lasting thermal stability were inspected.Paper studied thermal-oxidative aging dynamics. Effects that different antioxidantsaffected thermal-degradation of i-PB-1 were explored elementarily.When 1076 was used alone, shore of 0.1 was best. When shores of 1076 increased,effect came down. The antioxidant formula, which contained shore of 0.1 1010 andshore of 0.3 DLTP, prevented aging of i-PB-1 effectively. The best shore that B215prevented aging was shore of 0.3.When aging temperature was 110℃, aging results of long time thermal-oxidativeaging i-PB-1 showed that aging rate ofi-PB-1 without antioxidants was high. Aging 10hours, elongation at break of i-PB-1 was only 4.8% of aging-before's. Material lost itsfunctions. Antioxidants enhanced long-lasting thermal stability of i-PB-1 obviously.Effect of 1010 and DLTP on long-lasting thermal-oxidativity of i-PB-1 was best. Aging456 hours, tensile strength of i-PB-1 was 90.7% of aging-before's. Elongation at breakofi-PB-1 was 80.6% of aging-before's.According to spetra of IR, i-PB-1 ruptured chains under mechanical stress andheat, meanwhile, polymers containing end-group double-bond and carbonyl-goup weregenerated. According to spetra of TG/DTG, maximum thermal weight loss rate ofi-PB-1 without antioxidants was biger than i-PB-1 with antioxidant's in air and N₂ butthermal degradation activation energy of i-PB-1 without antioxidants was lower thani-PB-1 with antioxidant's. In air, thermal degradation of i-PB-1 was twice steps. In N₂,thermal degradation was primary degradation reaction.