| 查看: 639 | 回复: 3 | |||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | |||
[交流]
翻译
|
|||
|
Living polymerization techniques1 allow the synthesis of polymers with predictable molecular weights and narrowmolecular weight distributions, end-functionalized polymers andwell-defined block copolymers. While intense efforts haverecently focused on development of homogeneous single-site,early metal d0 and d0fn catalysts for polymerization of ethyleneand R-olefins (particularly propylene),2 rapid chain transferprocesses in these systems have limited their use as iving polymerization catalysts. The living polymerization of R-olefins has been achieved only in rare instances and at very low temperatures.3,4 We describe here the development of a procedurefor living polymerization of R-olefins based on recently reported NiII-R-diimine catalysts5 and application of this procedure to the synthesis of diblock and triblock poly(R-olefins). Access to well-defined transition metal olefin polymerizationcatalysts has allowed detailed mechanistic studies of this importantclass of catalysts. While much attention has centered on earlytransition metal d0 and lanthanide d0fn systems,1-7 we have focusedon developing single-site late metal catalysts. Our initial report8 that Ni(II) and Pd(II) aryl-substituted R-diimine complexes bearing bulky ortho substituents were capable of polymerizing ethyleneand R-olefins has stimulated extensive experimental9-20 andtheoretical21-27 work on these catalysts. The Pd(II) systems yield highly branched polyethylene under typical polymerization conditions,while the microstructure of polyethylene produced by theNi(II) systems is dependent on monomer concentration, reactiontemperature, and ligand structure. |
回复此楼» 猜你喜欢
290求调剂
已经有7人回复
-
电气专硕320求调剂
已经有5人回复
-
一志愿西北工业大学289 085602
已经有33人回复
-
一志愿哈工大 085600 277 12材科基求调剂
已经有24人回复
-
268分085602化学工程调剂
已经有28人回复
-
化学工程调剂289
已经有50人回复
-
求调剂，262机械专硕
已经有8人回复
-
305求调剂
已经有6人回复
-
327求调剂
已经有5人回复
-
347求调剂
已经有4人回复
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
2楼2010-09-16 21:12:47
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
3楼2010-09-16 21:38:01
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
4楼2010-09-16 21:40:03
5