24小时热门版块排行榜    

Znn3bq.jpeg
查看: 1272  |  回复: 5

超级小笨瓜

银虫 (小有名气)

[求助] RAFT试剂对强酸的稳定性问题

有做RAFT试剂的大神没,RAFT试剂(二硫酯)对有机强酸如三氟乙酸的稳定如何,能否在RAFT聚合的过程中加入强酸同时实现可控/"活性"聚合。
回复此楼

» 猜你喜欢

» 本主题相关商家推荐: (我也要在这里推广)

» 本主题相关价值贴推荐,对您同样有帮助:

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

shakete

金虫 (正式写手)

【答案】应助回帖

★ ★ ★ ★ ★
感谢参与,应助指数 +1
超级小笨瓜: 金币+3, 有帮助 2013-06-24 20:13:28
Meteorの泪: 金币+2, 感谢交流 2013-06-24 20:57:13
Chaleux好像一篇文章中提到过RAFT试剂在酸性条件下会水解
具体数值不太清楚,应该是70℃下几个小时内就有相当量的RAFT试剂水解
所以加入强酸之后可能会有一定的影响
2楼2013-06-24 18:16:53
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

超级小笨瓜

银虫 (小有名气)

引用回帖:
2楼: Originally posted by shakete at 2013-06-24 18:16:53
Chaleux好像一篇文章中提到过RAFT试剂在酸性条件下会水解
具体数值不太清楚,应该是70℃下几个小时内就有相当量的RAFT试剂水解
所以加入强酸之后可能会有一定的影响

能给下文章的题目么
3楼2013-06-24 20:13:49
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

love-study

至尊木虫 (职业作家)

【答案】应助回帖

★ ★ ★ ★
感谢参与,应助指数 +1
Meteorの泪: 金币+1, 感谢交流 2013-06-24 20:57:57
超级小笨瓜: 金币+3, ★★★很有帮助 2013-06-24 21:45:35
双硫脂在强酸体系里的稳定性不是很好,能发生酸解反应
学海无涯
4楼2013-06-24 20:25:30
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

shakete

金虫 (正式写手)

【答案】应助回帖

★ ★ ★ ★
超级小笨瓜: 金币+4, ★★★很有帮助 2013-06-25 15:50:41
Trithiocarbonates are known to be less subjected to hydrolysis than dithiobenzoate.(47, 48) However, a UV study performed at pH = 8.0 revealed that after only 30 min at 80 °C the absorbance of the PMAA macroRAFT agent at λ = 310 nm (corresponding to the maximum absorbance of the thiocarbonylthio function) decreased by 36% meaning that one-third of the chains had lost their RAFT chain end. After 5 h, only 14% of the chains still carried an active chain end. These results clearly explain the high amount of unreacted PMAA-CTPPA observed at this pH and the consequent poor control of the polymerization. By comparison, the hydrolytic stability of PMAA-CTPPA was significantly better at pH = 3.4 since a decay of only 4% was observed after 30 min at 80 °C and the proportion of living chains was still of 75% after 5 h (see Figure S2 in Supporting Information). In the emulsion polymerization performed at pH = 3.4, PMAA-CTPPA chains do not spend more than 45 min in the aqueous phase (Figure 1) and chain end hydrolysis can thus be neglected.


不知道怎么发图片,就把原句截下来了
http://pubs.acs.org/doi/full/10.1021/ma300875y这是文献的出处
atch Emulsion Polymerization Mediated by Poly(methacrylic acid) MacroRAFT Agents: One-Pot Synthesis of Self-Stabilized Particles
5楼2013-06-25 09:48:19
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

lanye6209

铁杆木虫 (正式写手)

一般pH在2以上不会有太大的影响,当然时间不能太长
在路上走走看看
6楼2013-06-26 10:35:38
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 超级小笨瓜 的主题更新
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考博] 博士自荐 +6 可可小胖 2026-04-08 6/300 2026-04-10 04:56 by 吴学通
[考研] 293调剂 +23 yj1221 2026-04-08 24/1200 2026-04-09 23:26 by may_新宇
[考研] 初试分332,一志愿报考西北工业大学, +11 故人?? 2026-04-09 11/550 2026-04-09 21:54 by JineShine
[考研] 301求调剂 +3 XYPLR 2026-04-05 5/250 2026-04-09 20:55 by lbsjt
[考研] 284求调剂 +8 让我上岸吧阿西 2026-04-09 10/500 2026-04-09 18:34 by 段伟艳
[材料工程] 材料调剂推荐 +3 蛋糕x2 2026-04-07 3/150 2026-04-09 17:01 by Lilly_Li
[考研] 求调剂材料科学与工程一志愿985初试365分 +5 材化李可 2026-04-08 5/250 2026-04-09 17:00 by Lilly_Li
[考研] 085501机械英二77总分294求调剂,接受跨专业学习 +6 守法公民亓纪 2026-04-08 6/300 2026-04-09 15:55 by wp06
[考研] 材料295 +15 小英11 2026-04-03 16/800 2026-04-09 15:44 by only周
[考研] 调剂 +12 月@163.com 2026-04-08 12/600 2026-04-09 14:27 by rl1980
[考研] 一志愿西南大学生物学学硕344 求生物学相关调剂/生物与医药 +7 超人不会飞@ 2026-04-08 7/350 2026-04-09 09:35 by gong120082
[考研] 材料专硕(0856) 339分求调剂 +16 哈哈哈鹅哈哈哈 2026-04-05 16/800 2026-04-08 16:02 by luoyongfeng
[考研] 生物工程求调剂 +13 喜欢还是不甘心 2026-04-05 13/650 2026-04-07 16:55 by Ecowxq666!
[考研] 312求调剂 +4 LR6 2026-04-06 4/200 2026-04-07 08:42 by jp9609
[考研] 307求调剂 +3 所念及所望 2026-04-06 3/150 2026-04-06 17:30 by 土木硕士招生
[考研] 0854求调剂 +4 assdll 2026-04-04 4/200 2026-04-05 09:44 by zhq0425
[考研] 083200 333求调剂 +3 十二!! 2026-04-04 3/150 2026-04-05 08:28 by barlinike
[考研] 调剂 +9 19945159693 2026-04-03 10/500 2026-04-04 20:16 by dongzh2009
[考研] 400分求调剂 +3 尴尬且挠头 2026-04-04 3/150 2026-04-04 08:41 by jp9609
[考研] 求调剂机会 +5 意染ivy 2026-04-03 5/250 2026-04-03 15:13 by qoooooo614
信息提示
请填处理意见