Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosph...Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosphoramide. The molecular weight of P（4-VP） was greatly affected by adding calix[4]arene-neodymium complex,and high molecular weight of P（4-VP） was got by using calix[4]arene-neodymium complex.The highest molecular weight of P（4-VP） was as high as 4.65×106 obtained by using a catalyst system with 2.0×10-4?mol/L of calix[4]arene-neodymium complex,while the molecular weight of P（4-VP） was only 5.62×105 without calix[4]arene-neodymium complex. In addition,4-VP-St copolymers with different 4-VP contents were obtained in good yield.When styrene was polymerized first for a time period,and then 4-VP was added,4-VP-St copolymers with 4.85?mol%～23.3?mol% of 4-VP units were obtained,but when 4-VP and styrene were added at the same time the resultant 4-VP-St copolymers had 44.0?mol%～66.3?mol% of 4-VP units.展开更多
文摘Homopolymerization of 4-vinyl pyridine（4-VP） and copolymerization of 4-VP with styrene（St） were performed by catalyst systems composed of calix[4]arene-neodymium complex 2,di-n-butylmagnesium and hexamethyl phosphoramide. The molecular weight of P（4-VP） was greatly affected by adding calix[4]arene-neodymium complex,and high molecular weight of P（4-VP） was got by using calix[4]arene-neodymium complex.The highest molecular weight of P（4-VP） was as high as 4.65×106 obtained by using a catalyst system with 2.0×10-4?mol/L of calix[4]arene-neodymium complex,while the molecular weight of P（4-VP） was only 5.62×105 without calix[4]arene-neodymium complex. In addition,4-VP-St copolymers with different 4-VP contents were obtained in good yield.When styrene was polymerized first for a time period,and then 4-VP was added,4-VP-St copolymers with 4.85?mol%～23.3?mol% of 4-VP units were obtained,but when 4-VP and styrene were added at the same time the resultant 4-VP-St copolymers had 44.0?mol%～66.3?mol% of 4-VP units.
