| 5 | 1/1 | 返回列表 |
| 查看: 1247 | 回復: 7 | |||
| 當前只顯示滿足指定條件的回帖,點擊這里查看本話題的所有回帖 | |||
[交流]
【求助】請問低分子量的硅氧烷和高分子量的硅氧烷如何分離?
|
|||
|
我現(xiàn)在在做的東西里含有低分子量的D4和分子量為3000左右的產(chǎn)物,由于產(chǎn)物里含有雙鍵,所以蒸餾的方法基本上是不予考慮了。請問各位有什么比較好的方法分離不同分子量的硅氧烷么?最好能有相關(guān)資料,謝謝了。。 我個人在想的是過柱子或者通過冷凍結(jié)晶的方法,但是具體的做法還沒查到。。。。 |
» 搶金幣啦!回帖就可以得到:
+1/280
+1/86
+1/80
+2/68
+1/50
+1/37
+1/34
+1/25
+1/16
+2/16
+1/11
+1/6
+1/6
+1/5
+1/4
+1/4
+1/3
+1/3
+1/2
+1/1
|
在文獻中看到的,“Model Networks Of End-Linked Polydimethylsiloxane Chains .1. Comparisons Between Experimental And Theoretical Values Of Elastic-Modulus And Equilibrium Degree Of Swelling” 其實雙鍵含量不是很高的話,減壓蒸餾關(guān)系不是很大的 The polymers used in this investigation were two samples of hydroxyl-terminated PDMS, hereafter designated A and B, described as having molecular weights the order of 2 x 104 and 1 xl 03 g morl , respectively. 26 Standard fractional precipitation techniquesl carried out at 25°C were used to separate these two polymers into several fractions. Toluene was chosen as the solvent and acetonitrile as the nonsolvent. (Methanol, which is widely used as the nonsolvent in polymer fractionations, cannot be used with polymer chains of this type, which have potentially reactive end-groups). Initial polymer concentrations were 1wt% in the case of sample A and 5wt% in the case of sample B. Four fractions (A-1 through A-4) were obtained from sample A, and two (B-1 and B-2) from sample B; each represented roughly 20% of the polymer from which it was obtained. [ Last edited by pengcil on 2010-12-22 at 10:33 ] |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 南京大學化學調(diào)劑 +9 | 景隨風 2026-03-29 | 14/700 |
|
|---|---|---|---|---|
|
[考研] 一志愿鄭州大學,080500學碩,總分317分求調(diào)劑 +8 | 舉個栗子oi 2026-03-24 | 9/450 |
|
|
[考研] 375求調(diào)劑 +4 | 雨夏整夜 2026-03-29 | 4/200 |
|
|
[考研] 279求調(diào)劑 +4 | 蝶舞輕繞 2026-03-29 | 4/200 |
|
|
[考研] 295求調(diào)劑 +4 | wei-5 2026-03-26 | 4/200 |
|
|
[考研] 一志愿太原理工安全工程300分,求調(diào)劑 +5 | 0857求調(diào)劑. 2026-03-24 | 6/300 |
|
|
[考研] 071000生物學求調(diào)劑,初試成績343 +7 | 小小甜面團 2026-03-25 | 7/350 |
|
|
[考研] 求調(diào)劑 +6 | 蘆lty 2026-03-25 | 7/350 |
|
|
[考研] 0856,材料與化工321分求調(diào)劑 +12 | 大饞小子 2026-03-27 | 13/650 |
|
|
[考研] 0703化學求調(diào)劑,各位老師看看我。! +5 | 祁祺祺 2026-03-25 | 5/250 |
|
|
[考研] 一志愿211院校 344分 東北農(nóng)業(yè)大學生物學學碩,求調(diào)劑 +5 | 丶風雪夜歸人丶 2026-03-26 | 8/400 |
|
|
[考研] 315調(diào)劑 +4 | 0860求調(diào)劑 2026-03-26 | 5/250 |
|
|
[考研] 314求調(diào)劑 +3 | 溪云珂 2026-03-26 | 3/150 |
|
|
[考研]
|
鐘llll 2026-03-26 | 4/200 |
|
|
[考研] 325求調(diào)劑 +3 | Aoyijiang 2026-03-23 | 3/150 |
|
|
[考研] 調(diào)劑 +4 | 柚柚yoyo 2026-03-26 | 4/200 |
|
|
[考研] 318求調(diào)劑 +3 | plum李子 2026-03-23 | 3/150 |
|
|
[考研] 求調(diào)劑 +6 | 研研,接電話 2026-03-24 | 7/350 |
|
|
[考研] 277分求調(diào)劑,跨調(diào)材料 +3 | 考研調(diào)劑lxh 2026-03-24 | 3/150 |
|
|
[考研] 344求調(diào)劑 +3 | desto 2026-03-24 | 3/150 |
|