选用芴基胺基二甲基钛配合物为主催化剂,在改性烷基铝氧烷(MMAO)和2,6-二异丙基苯酚(BHT)的活化下,进行了乙烯与1-十二烯的共聚。结果表明:芴基上引入叔丁基、胺基上引入金刚烷基的芴基氨基二甲基钛配合物对乙烯/1-十二烯的共聚表现出...选用芴基胺基二甲基钛配合物为主催化剂,在改性烷基铝氧烷(MMAO)和2,6-二异丙基苯酚(BHT)的活化下,进行了乙烯与1-十二烯的共聚。结果表明:芴基上引入叔丁基、胺基上引入金刚烷基的芴基氨基二甲基钛配合物对乙烯/1-十二烯的共聚表现出高活性;共聚活性随着Al与Ti物质的量比的增大逐渐上升,当Al与Ti物质的量比为1000时,达到最高活性,为2600 kg Polymer/(mol Ti·h),所得共聚物的重均分子质量最高达到2.7×10~6g/mol,当1-十二烯添加量为6.8 mmol时,共聚物中1-十二烯的插入率达到0.34%,此时共聚物的熔点为124.6℃。展开更多
Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesteri...Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesterification reaction. The effects of the crystallization conditions on melting behavior and SSP of BPA-PC were investigated with differential scanning calorimetry （DSC）, Ubbelohde viscosity method and gel permeation chromatography （GPC）. The reaction kinetics of the SSP of crystallized prepolymers was studied as a function of reaction temperatures for various reaction periods. As a result, the viscosity average molecular weight of BPA-PC particles （2 mm） increased from 1.9 × 10^4 g/mol to 2.8 × 10^4 g/mol after SSP. More importantly, the significantly enhanced thermal stability and mechanical properties of solid-state polymerized BPA-PC, compared with those of melt transesterification polymerized BPA-PC with the same molecular weight, can be ascribed to the substantial avoidance of undergoing high temperature during polymerization. Our work provides a useful method to obtain practical product of BPA-PC with high quality and high molecular weight.展开更多
文摘选用芴基胺基二甲基钛配合物为主催化剂,在改性烷基铝氧烷(MMAO)和2,6-二异丙基苯酚(BHT)的活化下,进行了乙烯与1-十二烯的共聚。结果表明:芴基上引入叔丁基、胺基上引入金刚烷基的芴基氨基二甲基钛配合物对乙烯/1-十二烯的共聚表现出高活性;共聚活性随着Al与Ti物质的量比的增大逐渐上升,当Al与Ti物质的量比为1000时,达到最高活性,为2600 kg Polymer/(mol Ti·h),所得共聚物的重均分子质量最高达到2.7×10~6g/mol,当1-十二烯添加量为6.8 mmol时,共聚物中1-十二烯的插入率达到0.34%,此时共聚物的熔点为124.6℃。
基金financially supported by the National Natural Science Foundation of China(No.51173112)
文摘Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesterification reaction. The effects of the crystallization conditions on melting behavior and SSP of BPA-PC were investigated with differential scanning calorimetry （DSC）, Ubbelohde viscosity method and gel permeation chromatography （GPC）. The reaction kinetics of the SSP of crystallized prepolymers was studied as a function of reaction temperatures for various reaction periods. As a result, the viscosity average molecular weight of BPA-PC particles （2 mm） increased from 1.9 × 10^4 g/mol to 2.8 × 10^4 g/mol after SSP. More importantly, the significantly enhanced thermal stability and mechanical properties of solid-state polymerized BPA-PC, compared with those of melt transesterification polymerized BPA-PC with the same molecular weight, can be ascribed to the substantial avoidance of undergoing high temperature during polymerization. Our work provides a useful method to obtain practical product of BPA-PC with high quality and high molecular weight.
