w********h
发帖数: 12367 | 1 low molecular weight?
for 1,4-PBD, i know it happens for low molecular weights.. | r****r
发帖数: 14 | 2 Where is the endotherm? The equilibrium melting temperature for cis-1,4-PI is
around 35C. The real Tm will be 20C sth. If you store your sample at room
temperature, I don't think you can find a melting peak. Have you ever quenched
it to very low temperature like below 0C? Check the paper by PJ Phillips:
Macromolecules 1987, 20, 2138. | r****r
发帖数: 14 | 3 For trans-1,4-polyisoprene, the Tm may be over 60C. In that case, you may have
chance to get it crystallized at room temperature. | w********h
发帖数: 12367 | 4 我想他说得是cis, trans 1,4-PIP, 1,2-PIP的mixture吧，
一般阴离子聚合的产物如此，非纯trans 1,4-PIP.
pure trans 1,4-PIP没得话说，当然结晶。
//问zzwh,多少分子量？什么温度上有结晶峰？
is
quenched
【在 r****r 的大作中提到】
: Where is the endotherm? The equilibrium melting temperature for cis-1,4-PI is
: around 35C. The real Tm will be 20C sth. If you store your sample at room
: temperature, I don't think you can find a melting peak. Have you ever quenched
: it to very low temperature like below 0C? Check the paper by PJ Phillips:
: Macromolecules 1987, 20, 2138.
| z**h
发帖数: 224 | 5 sorry, people, it is a fake peak. I got nothing from DSC. PS-PI, Mw 15.4k-9k,
from -60C to 110C.
【在 w********h 的大作中提到】
: 我想他说得是cis, trans 1,4-PIP, 1,2-PIP的mixture吧，
: 一般阴离子聚合的产物如此，非纯trans 1,4-PIP.
: pure trans 1,4-PIP没得话说，当然结晶。
: //问zzwh,多少分子量？什么温度上有结晶峰？
:
: is
: quenched
|
|
