s*****i
发帖数: 146 | 1 I synthesized PLA-PEG-PLA triblock polymer. But there is a strange peak at 1
.7
5-1.8 next to the peak at 1.56 ppm which is attributed to the CH3 of lactide
u
nits. I wonder whether the strange peak belongs to water? but I checked that
w
ater in CDCl3 is 1.5 ppm, NOT 1.75-1.8 ppm. Is there sb who knows?
3x a lot |
s****e
发帖数: 2934 | 2 1。5ppm的水峰是个宽的单峰，你的峰是怎么样的呢？还有你用CDCl3的proton做内标定
位了吗？这个峰在7。26ppm。 NMR样品不纯很难说吧？
1
lactide
that
【在 s*****i 的大作中提到】
: I synthesized PLA-PEG-PLA triblock polymer. But there is a strange peak at 1
: .7
: 5-1.8 next to the peak at 1.56 ppm which is attributed to the CH3 of lactide
: u
: nits. I wonder whether the strange peak belongs to water? but I checked that
: w
: ater in CDCl3 is 1.5 ppm, NOT 1.75-1.8 ppm. Is there sb who knows?
: 3x a lot
|
s*****i
发帖数: 146 | 3 I synethesized two bacth. One is a broad peak, the other is a narrow one.
there is no water in CDCl3. is it possible water exit in the diethyl ether?
I use this to perticipate my sample.
【在 s****e 的大作中提到】
: 1。5ppm的水峰是个宽的单峰，你的峰是怎么样的呢？还有你用CDCl3的proton做内标定
: 位了吗？这个峰在7。26ppm。 NMR样品不纯很难说吧？
:
: 1
: lactide
: that
|
h***s
发帖数: 111 | 4 Could it be oxidized ether? You can check this by adding some ether in NMR
tube, and evaporate most
ether, then run an NMR in CDCl3.
?
【在 s*****i 的大作中提到】
: I synethesized two bacth. One is a broad peak, the other is a narrow one.
: there is no water in CDCl3. is it possible water exit in the diethyl ether?
: I use this to perticipate my sample.
|
