K****N
发帖数: 10783 | 1 dmf估计可以
也可以试ethyl acetate, thf, dioxane, dcm, toluene， ether等，或者混合溶剂 |
|
q****e
发帖数: 3660 | 2 need a patent, and please send to l***************[email protected]
Thanks a lot!
IMPROVED ESTERIFICATION OF OXYHYDROCARBON POLYOLS AND ETHERS THEREOF, AND
PRODUCTS THEREFROM, -1992000947/WO-A1/
1992-01-23 1992000947/WO-A1 NDN- 052-0134-0935-5 PCN Univentio
INVENTOR-MILSTEIN, Norman
DATE FILED-1991-07-09
PUBLICATION NUMBER-1992000947/WO-A1
DOCUMENT TYPE-A1
PUBLICATION DATE-1992-01-23 |
|
l**2
发帖数: 20 | 3 Tetrahedron Letters, Volume 25, Issue 23, 1984, Pages 2411-2414
Improved highly efficient synthesis of α,β-acetylenic ketones. Nature of
the intermediate from the reaction of lithium acetylide with boron
trifluoride etherate
Herbert C. Brown, *, Uday S. Racherla, Shankar M. Singh and Richard B.
Wetherill |
|
d****i
发帖数: 360 | 4 Help me, Please! Thanks a lot!
E-mail: x**********[email protected]
International Journal of Pharmaceutics
Volume 311, Issues 1-2, 27 March 2006, Pages 215-222
Effects of conditions for preparing nanoparticles composed of
aminoethylcarbamoyl-β-cyclodextrin and ethylene glycol diglycidyl ether on
trap efficiency of a guest molecule
Masaru Eguchia, Yong-Zhong Dua, 1, Yoshikatsu Ogawaa, Tomoko Okadaa,
Noboru Yumotob and Masato Kodakaa, |
|
e****2
发帖数: 2723 | 5 这样的酸催化剂容易和空气的水反应，产生微量HF ，自然有雾气
不必理会。 出现颜色液滴是因为溶解性不同而已
ether
trifluoride |
|
f********h
发帖数: 247 | 6 加入到epichlorohydrin里的时候，白雾非常大。epichlorohydrin已经是除过水的了，
这是为什
么呢？
ether
trifluoride |
|
R******i
发帖数: 33 | 7 I planned to synthesize two diketonates using Claisen Condensation reaction.
1, 2-acetothiophene+ethyl 2-thiophenecarboxylate
2, 2-acetylnaphthalene+ethyl2-naphathoate
use sodium methoxide as base and diethyl ether as solvent,acdify using HCl.
Question:
Reaction time (at RT)? Yield? How to promote the yield? How to purify the
product?
Thank you very much for your expert opinion. |
|
s***r
发帖数: 67 | 8 The isomerism of the oximes. Part XXVI. The methyl ethers of the aldoximes
Oscar L. Brady, Frederick P. Dunn and Richard F. Goldstein, J. Chem. Soc.,
1926, 2386
DOI: 10.1039/JR9262902386
3X |
|
c******x
发帖数: 438 | 9 Competing processes for poly(aryl ether-ketone) synthesis, 3†.
Polymerization reactions of 1,3-bis(4-chlorobenzoyl)benzene and 1,3-bis(4-
fluorobenzoyl)benzene in N-methyl-2-pyrrolidinone
Atul Bhatnagar, Rajrathnam S. Mani, Brandon King, Dillip K. Mohanty
Macromolecular Chemistry and Physics
Volume 197, Issue 1, pages 315–328, January 1996
Thanks |
|
|
s*********n
发帖数: 68 | 11 Polymer Bulletin
Volume 35, Number 3, 291-297, DOI: 10.1007/BF00963126
Synthesis of poly(vinyl alcohol)s with narrow molecular weight distribution
from poly(benzyl vinyl ether) precursors
Clive Forder, Steven P. Armes and Norman C. Billingham
s*********[email protected]
Thanks a lot. |
|
r******s
发帖数: 3662 | 12 【 以下文字转载自 NanoST 讨论区 】
发信人: rayfalls ( b), 信区: NanoST
标 题: [大包子求帮助]金属nanoparticle如何在溶剂中分散？
发信站: BBS 未名空间站 (Wed Feb 16 11:08:47 2011, 美东)
小弟不才，摸索着做这破玩意也快两年了，可是每次做出来的particle分散性时好时不
好，surfactant用
的是oleic acid，在phenyl ether中需要加热到200度。清洗是用酒精和正己烷hexane
反复洗三次，洗完
之后有时能分散进非极性溶剂比如说甲苯,有的能分散进极性溶剂比如说丙酮，有时候
啥也分散不进去。
跟别人讨论有的说洗的太多了把surfactant都洗掉了，也看有的人做的时候最后洗完再
加一滴oleic acid
然后加1:3 hexane/methanol摇匀后去掉上清液再分撒，这招也是时灵时不灵，有时候
能分散很好，有
时候进TEM看还是一团粘在一起的。
在此不惜散尽家产请求各位大牛帮助，有帮助的给建议的双簧包，有帮助的十个大包子
，谢谢各位了。 |
|
s***r
发帖数: 67 | 13 Nelson, T. D.; Crouch, R. D.
"Selective deprotection of silyl ethers."
Synthesis 1996, 1031–1069.
doi:10.1055/s-1996-4350 |
|
d********w
发帖数: 1110 | 14 反应物在酸性条件下不是很稳定。我的做法是：先旋蒸除掉大部分pyridine,再用1N 的
盐酸快速的把有机相（ether溶液）洗两遍。可是最后产率不是很高，不知道是不是洗
坏了。请问谁还有更好的办法？不想用油泵减压抽，不知道NH4Cl好使不。 |
|
J*J
发帖数: 132 | 15 不好意思， 不知道那个连接不能用，这是其他的Info
Convenient preparations of t-butyl esters and ethers from t-butanol
Tetrahedron Letters, Volume 38, Issue 42, 20 October 1997, Pages 7345-7348
Stephen W. Wright, David L. Hageman, Ann S. Wright, Lester D. McClure
谢谢了 |
|
j**********i
发帖数: 187 | 16 Article:
Crown Ethers with a Lewis Acidic Center: A New Class of Heterotopic Host
Molecules
Author: Reetz, Manfred T.
Journal:
Angewandte Chemie International Edition in English
ISSN: 0570-0833
Date: 11/1991
Volume:
30
Issue:
11
Page:
1472
DOI:
10.1002/anie.199114721 |
|
p****g
发帖数: 70 | 17 PEEK polyether ether ketone那个苯上的氢 (PhCOPh)的PKA是多少有人知道么?
LDA是36, 苯上氢是43, |
|
|
s****r
发帖数: 736 | 19 由于试验需要，在水相反应中必须添加一定量表面活性剂。在反应结束后，又必须去除
该表面活性剂。现在基本的想法用有机物萃取分离表面活性剂。但是该表面活性剂亲水
性很高（HLB ~10）， 一般的有机物，如hexane，diethyl ether，都无法将其萃取出
来。所以在此求教各位xdjm，有什么好的萃取剂推荐么？ |
|
S***k
发帖数: 158 | 20 单体是：N-(Isobutoxymethyl)acrylamide，里面的阻聚剂是200 ppm monomethyl
ether hydroquinone。单体本身会和CaH、Na等反应，所以不能通过这种办法除水、除
阻聚剂。Sigma-Aldrich给的单体沸点是108摄氏度，阻聚剂沸点256度，所以我就想用
减压蒸馏来除阻聚剂。
问题出在减压蒸馏上：我减压蒸馏蒸到了200度，这东西还是没出来，最后升到了230度
才有少许的单体流出来。这样蒸基本上50mL的单体能蒸出来10mL就不错了，剩下的全在
瓶子里聚合后玻璃化了。而且蒸出来的东西我也不确定有没有阻聚剂残余（含量太低，
NMR也很难看出来）。
想问一下有没有人有处理过这一类型单体的经验。按理说108度沸点的单体，就算是常
压下蒸也不需要200+度吧。难道是这种类型的单体比较特殊？ |
|
S***k
发帖数: 158 | 21 单体是：N-(Isobutoxymethyl)acrylamide，里面的阻聚剂是200 ppm monomethyl
ether hydroquinone。单体本身会和CaH、Na等反应，所以不能通过这种办法除水、除
阻聚剂。Sigma-Aldrich给的单体沸点是108摄氏度，阻聚剂沸点256度，所以我就想用
减压蒸馏来除阻聚剂。
问题出在减压蒸馏上：我减压蒸馏蒸到了200度，这东西还是没出来，最后升到了230度
才有少许的单体流出来。这样蒸基本上50mL的单体能蒸出来10mL就不错了，剩下的全在
瓶子里聚合后玻璃化了。而且蒸出来的东西我也不确定有没有阻聚剂残余（含量太低，
NMR也很难看出来）。
想问一下有没有人有处理过这一类型单体的经验。按理说108度沸点的单体，就算是常
压下蒸也不需要200+度吧。难道是这种类型的单体比较特殊？ |
|
C*******b
发帖数: 174 | 22 做一个model RCM reaction，如附图，但是产率只有百分之三十左右。用的是Grubbs
II，浓度0.01 M，回流两天，然后用ethyl vinyl ether淬灭，浓缩，然后走柱子。结
果产率只有百分之三十左右。并且得到了一些粘稠黑黑的看似低聚物的东西。不知道我
的反应问题何在，请高手指点一二。十分感谢。 |
|
j***j
发帖数: 560 | 23 Solvent-free synthesis of cyclic ethers from dihalo compounds in the
presence of alumina
Mihara, Masatoshi
Synlett, (9), 1526-1528; 2002
Thanks in advance,
[email protected]
/* */ |
|
s******s
发帖数: 699 | 24 表哥回家过年去了让我帮他下，可是我们学校医学院没有订阅，求大牛们帮忙下载，包
子答谢：）
我的邮箱是：[email protected]
/* */
文章是：
Recent development of carbon electrode materials and their bioanalytical and
environment applications.
还有一篇
Simultaneous volammetric determination of heavy metals by use of crown ether
modified eletrodes and chemometrics.
再次谢谢大家了。 |
|
d********y
发帖数: 176 | 25 http://onlinelibrary.wiley.com/doi/10.1002/masy.19900320118/pdf
On the nature of active species in cationic ring-opening polymerization of
cyclodimethylsiloxanes
Authors
Pierre Sigwalt,
Vivian Stannett
First published: February 1990Full publication history
DOI: 10.1002/masy.19900320118View/save citation
Cited by: 5 articlesCitation tools
Abstract
Contrarily to cationic ring-opening polymerization of cyclic ethers and of
some other cyclic monomers, for which direct identification of the various
t... 阅读全帖 |
|
g*****j
发帖数: 1211 | 26 中医阴阳五行六经，博大精深，是世界古代医学中的一颗明珠。有人说中医是医学的
最高境界，因为它的理论来自自然界的更本规律。将哲学，物理和医学结合起来，自
然会觉得这样的理论是自然界的最高理论。那是不是我们的祖先特别聪明，能够发现
这样的自然界根本规律呢？
我们来看看世界上的其他文明中，哲学，物理，医学是如何发展的呢？
古希腊的哲学认为世界由四种element组成，而人和自然界的万物一样，也离不开
四种element。而这四种element在人体中也能找到相对应的体系。见图1， 图2。
印度文明的哲学叫做Samkhya。它认为世界有两种最更本的principles：Purusha
and Prakrti; 而自然界由五种物质：ether, air, fire, water and
earth组成。见图3。
不难看出，不同的古代文明对自然界，物理学，医学的认识惊人的相似。其理论的结
构几乎是一致的，只是具体的解释各个文明略有不同。其中水，火，土，更是不约而
同地被三种伟大文明同时认为是自然界最根本的元素。这种巧合是否一定程度上是人
类对自然认识的必然过程呢？要知道元素周期表的发现也只是最近一 |
|
h*****n
发帖数: 924 | 27 yes, i totally agree. the funny thing in china is, all journals and books ne
ed a series number approved by the gov't, and this number specifies it is wh
ether a book or a journal.
i guess the standard to be a journal is higher, such that some journals cann
ot be officially journals, but books. only official journals have "levels,"
s
omething stupid called level 1, level 2, authority... These levels are be
nchmarks for promotion decisions.
US academia has something similar, but it is very depart |
|
J*R
发帖数: 187 | 28 One postdoctoral research fellow position is available from Oct 1 or
earlier. The successful candidate will work on one of the following topics
depending on his/her background and expertise: novel morphing structures
using smart materials, mechanics of morphogenesis in embryos, fast motion of
plants (e.g., the Venus flytrap's rapid closure), and mechanical
instability of thin structures (e.g., DNA, plant tendrils, self-assembly of
nanostructures, etc.). The candidate should have received (or exp... 阅读全帖 |
|
w********h
发帖数: 12367 | 29 diethyl ether
suggest u read this paper:
Dynamic viscoelasticity study of the phase transition of
poly(N-isopropylacrylamide)
Macromolecular Rapid Communications
Volume: 21, Issue: 8, May 2000. pp. 476 - 480.
Hsu, Shan-hui; Yu, Tzyy-Lung |
|
b**s
发帖数: 589 | 30 现在才反应过来diethyl ether 就是乙醚
我认为沉淀剂的选择应该有以下的特点
1。必须是不良溶剂(不用说)
2。必须便宜(用量较多)
3。必须容易挥发(一般要放到红外灯下烘干)
要沉淀充份
1。不良溶剂量要足
2。沉淀时间要足够(要能把小分子的部分也沉下来，以使样品保持原样)
3。你的样品分子量要觉高一点 |
|
w********h
发帖数: 12367 | 31 薛奇老师的文章你应该看过？
A CONDUCTING POLYMER FILM STRONGER THAN ALUMINUM
SHI GQ, JIN S, XUE G, LI C
SCIENCE
267: (5200) 994-996 FEB 17 1995
Document type: Article Language: English Cited References: 25
Times Cited: 41
Abstract:
Polythiophene (Pth) was electrochemically deposited onto stainless steel
substrate from freshly distilled boron fluoride-ethyl ether containing 10
millimoles of thiophene per liter. The free-standing Pth film obtained at an
applied potential of 1.3 volts (versus Ag/A |
|
c****e
发帖数: 252 | 32 Does anyone know where to buy poly (vinyl methyl ether)(PVME)? I find that in
Aldrich there is only PVME solution for sale. I need some pellets of PVME. |
|
c*******n
发帖数: 1648 | 33 I don't think the free radical can make it, degradative chain transfer could
happen. However, the cationic polymerization probably do. If you have time,
check out some textbook on polymerization, such as Odian's. Take a look at the
table for monomer and corresponding polymerization method. Generally vinyl
ether can not be polymerized by free radical.
of |
|
c****n
发帖数: 134 | 34 Thanks a lot guys.
Chenchuan is right. DMSO is a better solvent for homoPVA, since PVA dissolves
much faster than in water (as I observed). One more fact:
polyisobutylene-b-poly(methyl vinyl ether) is soluble in water when DPn of PIB
is 50 and DPn of PMVE is 260. (PMVE is water soluble). Seems two factors work
together resulting the insolubility of the PIB-PVA in water: "This additional
kind of long range
orderness (from PIB) will make it more difficult to be attacked by solvent";
water is weak |
|
c****n
发帖数: 134 | 35 A thermoplastic elastomer...and I need to see the morphology
for butadiene and styrene, it is well-known.
but now I need to taint a poly(vinyl ether).
any idea? perhaps I can acknowledge you in a paper :)
(this is last result for a paper.
To measure the TEM, my boss has to cooperate with another prof.
with a promise of coauthorship...I am sad. I worked so hard, it is too easy
for the cooperator!) |
|
p******s
发帖数: 137 | 36 来自主题: Macromolecules版 - 我看炸药奖 ft..
你说学科分类过时不错，但Nobel Prize和纯理论的关系可不是这样，
很多的奖都是颁给了那些具有十分重要意义的技术进步，
如STM/AFM, NMR etc..
也有很多的奖是颁给了开创新领域的实验，
如C60(although this one is not so good), crown ether...
Nobel prize不牛，还有谁牛？老大你醒醒。
搞数学的只能怪那个把Nobel老婆拐走的那个数学家，
但他们也有Wolf和Fields拿拿，
一般开发软件的就算了吧，不过你做模拟牛也是可以拿的，
开发个什么molecular dynamics等等不也照拿？
什么叫做非理性的发现？
机遇表面来自于偶然，但更必然。
更何况一个偶然发现就能获得Nobel奖的时代早就过去了，
你必须得抓住现象看本质，然后打通一片天地才好获奖。
科
。
现 |
|
r******0
发帖数: 2753 | 37
The difference between alchol and ester is much larger than alchol and ether.
~~~~
C-NMR may be more sensitive on this case.
I do hope you are right. Low MW polymer and very good NMR might tell the
difference. What I did is give you other possibilities that you may need
consider. Another suggestion is to order some very low MW poly(ethylene
glycol) and see if you NMR can see the chain end. If yes, you are right; if
not, :(
overlap.
ends
good |
|
s****e
发帖数: 2934 | 38 Thank you very much for your comprehensive information!
I need to measure electric properties of my compound, so a thin layer of
PMMA is not ok for me. My compound is also a silicone compound, which is a
nonpolar. I have tried xylene, toluene, hexane, THF, ether. For xylene and
toluene, only 50%-40% can fully wet the wafer before I spin the spinner. So
all the other concentration can not fully wet the surface, everything is
gone when spin for 2mins at 1500RPM. For the 40% one, crystalline is big |
|
c*s
发帖数: 2145 | 39 azotropic distill then precipitate it in ether followed by vacuum dry, you
will get fine poder
去，
原来
不知 |
|
s*****i
发帖数: 146 | 40 先前我问了一个关于他们溶解性的问题，后来我突然想到是不是里面PLA-PEG 的比例也
会影响溶解性？如果是的话从可溶到不可溶（溶剂为水，或者CH2CL2 或者DMF）转变点
PLA/PEG ratio是多少？ 有没有大牛指点一下？
还有就是 我将聚合物沉淀在乙醚里面，得到的是粘粘的，粘在哪里都是，也不好洗下
来，我看见既有用diethyl ether/hexane or diethylether/methanol来沉淀的，是不
是这样得到的聚合物形态好？如果是的话一般混合溶剂比例大概多少？
问题比较多，因为是新手，大家不要见怪，谢谢大家！ |
|
s*****i
发帖数: 146 | 41 今天作了沉淀,试了一下 diethyl ether/methanol 85/15得到形态好的聚合物 |
|
s****e
发帖数: 2934 | 42 ☆─────────────────────────────────────☆
cds (红毛呼呼猪) 于 (Sun Oct 1 23:40:38 2006) 提到:
thanks a lot. BUt my case is kinda special. it is PEG-PtBA, as u know, PtBA
can be dissolved in almost all solvents except water. therefore, the
solubility property of the block polymer is quite similar to homopolymer.
what I am trying to do is to precipitate PEG in MeOH using ether, while
keeping the block polymer micelles in MeOH. This looks viable but I am not
sure this is the best combination or not in |
|
s*****i
发帖数: 146 | 43 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. |
|
s****e
发帖数: 2934 | 44 如果随便找一个塑料瓶，这样会不会有添加剂溶于perfume吧。perfume里面大概都是花
草类的提取物和ether啊，ethanol这些吧？ |
|
c******h
发帖数: 4573 | 45 不是。。。
我做poly arylene ether sulfone |
|
j***n
发帖数: 19 | 46 apply some organic solvents on PMA first such as chloroform, aetone or ether
.
the |
|
c*******n
发帖数: 1648 | 47 Isn't a cosolvent better?
ether |
|
d****n
发帖数: 237 | 48 我觉得能，两者先按照1：1的比例形成charge transfer complex（CTC），得到几乎为
交替结构的共聚物。如果前者的AAm过剩则可以得到交替共聚物与PAAm的混合物，如果
是后者过剩，则得到交替共聚物和残余单体B。
allyl ether就可以与马来酸酐通过自由基聚合形成alternating copolymers |
|
d****n
发帖数: 237 | 49 1984和Kennedy一起搞出了isobutene的阳离子活性聚合；稍晚于1982年Sawamoto的
vinyl ether体系的阳离子活性聚合。 |
|
s********0
发帖数: 1 | 50 Title: Single-pot synthesis of methyl tert-butyl ether from tert-butyl
alcohol and methanol: dodecatungstophosphoric acid supported on clay as an
efficient catalyst
Author: G. D. Yadav and N. Kirthivasan
Source: J. Chem. Soc., Chem. Commun., 1995, 203 - 204,
DOI: 10.1039/C39950000203
http://www.rsc.org/publishing/journals/C3/article.asp?doi=c39950000203
Thank you very much! |
|
