b**s
发帖数: 589 | 1 【 以下文字转载自 Chemistry 讨论区,原文如下 】
发信人: boss (养蜂人@城市), 信区: Chemistry
标 题: oxidative polymerization Re: What can be polymerized by APS?
发信站: The unknown SPACE (Sat Nov 16 23:33:32 2002) WWW-POST
实在不明白咱们说的是不是一个东西，到底什么是oxidative polymerization？
我的理解是因为氧化产生free radicals，再引发链增长，这就是oxidative
polymerization
这在油漆，涂料行业是很常见的，基本上有双键就行。
能否给我提供一些你所谓的oxidative polymerization 的资料，我也要refresh一下
了
used
discussed
no
are
polymerization? |
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m******i
发帖数: 834 | 2 17 October 2006; Vol. 103, No. 42
TOC:
1. Polymerization Special Feature: Introduction: Polymerization
Tobin J. Marks
2. Polymerization Special Feature: Surface science of single-site
heterogeneous olefin polymerization catalysts
Seong H. Kim and Gabor A. Somorjai
3. Polymerization Special Feature: Nuclearity and cooperativity effects in
binuclear catalysts and cocatalysts for olefin polymerization
Hongbo Li and Tobin J. Marks
4. Polymerization Special Feature: Kinetic resol |
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c********r
发帖数: 189 | 3 问一个关于蛋白polymerization的问题，一般来说transcription factor polymerization是不是只有两种情况：translation的时候cotranslational dimerizition；或者binding DNA的时候继续polymerize来稳定与DNA的相互作用。
在用overexpression研究这个问题的时候，有没有可能观察到的polymerization是overexpression的artifact呢？ |
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w******z
发帖数: 29 | 4 I used AIBN to polymerize the MMA in bulk. the trick is before the
autoaccelaration, decrease the temperature (-20oC) and continue it at lower
temeprature with a longer time.
and boss is right, bulk polymerization will got much higher Mw than solution
polymerization. if you want lower Mw, increase the amount of AIBN and
temperature and use solution polymerization. there should be a equation to
estimate the Mw but I forgot. you can get it from any polymer synthesis book.
good luck!
现 |
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z**h
发帖数: 224 | 5 usually we refer ionic polymerization as living polymerization. step
polymerization may be regarded as living polymerization. |
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c*w
发帖数: 50 | 6 I want to polymerize poly(ethylene glycol) and lactide in 150 degree, stannous
octoate as catalyst. no water and high vacuum is very important.
In fact, many papers have described the polymerization: a polymerization tube
or flask connected with vacuum pump.
However, i found it's very difficult to find a suitable flask and very
difficult to keep the vacuum during the reaction.
Anyone who do this can teach me?
Thanks a lot!! |
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a*i
发帖数: 1652 | 7 just found that styrene was self-polymerized in a SS tube. same styrene in a
PE tube was not polymerized. Stainless steel might have initiate the
polymerization.
anybody with similar experiences? |
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d****c
发帖数: 4 | 8 Job Description
Description:
The Department of Biomedical Engineering at the University of Minnesota
currently has an opening for a post-doctoral fellow to conduct studies in
engineering of polymeric biomaterials. The biomaterials are used for
regulating cell-microenvironment interactions, constructing stem cell niches
, and tissue regeneration.
Qualifications:
Candidates must have a Ph.D. in a field of study related to biomaterials
engineering. The ideal candidate will have experience in the ar... 阅读全帖 |
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b******e
发帖数: 3348 | 9 一个人一天吃几克盐，正常，让他一次半斤，结果齁死了。得出结论，吃盐让人死亡。
polymerization是不是只有两种情况：translation的时候cotranslational
dimerizition；或者binding DNA的时候继续polymerize来稳定与DNA的相互作用。
overexpression的artifact呢？ |
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d****c
发帖数: 4 | 10 Description:
The Department of Biomedical Engineering at the University of Minnesota
currently has an opening for a post-doctoral fellow to conduct studies in
engineering of polymeric biomaterials. The biomaterials are used for
regulating cell-microenvironment interactions, constructing stem cell niches
, and tissue regeneration.
Qualifications:
Candidates must have a Ph.D. in a field of study related to biomaterials
engineering. The ideal candidate will have experience in the areas of
chemical ... 阅读全帖 |
|
d****c
发帖数: 4 | 11 Description:
The Department of Biomedical Engineering at the University of Minnesota
currently has an opening for a post-doctoral fellow to conduct studies in
engineering of polymeric biomaterials. The biomaterials are used for
regulating cell-microenvironment interactions, constructing stem cell niches
, and tissue regeneration.
Qualifications:
Candidates must have a Ph.D. in a field of study related to biomaterials
engineering. The ideal candidate will have experience in the areas of
chemical ... 阅读全帖 |
|
b**s
发帖数: 589 | 12 找到一片文章，人家是用溶液聚合，跟你的本体聚合不一样。你这是叫自加速现象，
高分子的东东忘光了？呵呵
PVI was prepared by solution polymerization using
2,2'-azobis(isobutyronitrile) (AIBN) as initiator. 1-Vinylimidazole (20 ml)
was dissolved in 50 ml absolute ethanol and dry nitrogen was bubbled through
the solution with vigorous stirring. AIBN (0.04 g) was added to the solution
and polymerization was carried out at 70°C for 40 h. PVI was obtained by
precipitating the ethanol solution in excess THF/hexane (3:8, v/v) solution. |
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t***m
发帖数: 114 | 13 for ATRP and RAFT we follow different criteria
though both are not exact "living" polymerization.
maybe call it controlled polymerization is better. |
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m*****e
发帖数: 1506 | 14 try polar solvents like DMF or DMSO
try polymerization at high temperature
it also depends on what kind of monomer and what kind of polymerization. |
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d****c
发帖数: 4 | 15 Description:
The Department of Biomedical Engineering at the University of Minnesota
currently has an opening for a post-doctoral fellow to conduct studies in
engineering of polymeric biomaterials. The biomaterials are used for
regulating cell-microenvironment interactions, constructing stem cell niches
, and tissue regeneration.
Qualifications:
Candidates must have a Ph.D. in a field of study related to biomaterials
engineering. The ideal candidate will have experience in the areas of
chemical ... 阅读全帖 |
|
发帖数: 1 | 16 第一次发申请，不知道有没有Bio-oil生物油或者聚合物polymerization相关领域的审
稿机会，非常感谢，CV邮件发送 |
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P**A
发帖数: 17 | 17 Polymeric nanoparticles
PM your Info. |
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B*****I
发帖数: 1378 | 18 就是简单的mma，3MBP,crosslinker
用个prepacked column除inhibitor
可是看了一下那个column颗粒非常大，流得非常快，有点担心是不是没有除干净
inhibitor
用很强的光照了一个小时才polymerize了，似乎太慢了。。是不是?
3MBP用了最多有4%,也没用
啥问题？换柱子么？ |
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y******n
发帖数: 8667 | 19 用TIRF or fluorescence microscopy来研究tubulin dynamic in vitro regulated by
other tip proteins.
But now I met a lot of problems:
1. Is labeled tubulin and tubulin easy to lost their activity in vitro?
2. What conditions is better for their polymerization?
以前看到过很好的GMPCPP seeds， 但之后再也重复不出来了。同一批labeled的
tubulin蛋白好象都形成一些很亮的点，应该是蛋白凝聚了或变性了。但新labeled 的
tubulin 也不行。有人有什么建议吗？ |
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a*i
发帖数: 1652 | 20 After solution polymerization, the polymer needs to be purified and dried
into powdered form. Purification is easy---just use lots of water to extract
. How about the drying process? How to make the polymer powdery in the end (
the polymer is glassy at room temperature)? I am not sure how the chemical
industry handles that. Thanks for your suggestion. |
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x*****g
发帖数: 82 | 21 Ihre, Henrik; Soederlind, Erik; Hult, Anders. Synthesis and
characterization of dendritic aliphatic polyesters based on 2,2-bis(
hydroxymethyl)propionic acid. Polymeric Materials Science and Engineering
(1995), 73 351-2. |
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z*******g
发帖数: 9 | 22 大虾帮忙。。
我要做一个本体聚合（BULK POLYMERIZATION)合成PVI，可是这个温度过热问题
简直没办法似的。每次都是到了70度没一秒钟的时间，温度就已经冲上去了，等
在冷却下来，反应已经完了，高分子全部都固化了。
对于这个问题大家有什么好的建议吗？我是想通过这个得到低分子量的高分子。
文献上还说在70度反应2个小时，我就不知道怎么反应2个小时。温度一过热整个
反应液就变成了固体，还反应个啥？
最近被这个折磨死了，先多谢大家了。。。
SIGH.... |
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z*******g
发帖数: 9 | 23 btw..it is a free radical polymerization... |
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z*******g
发帖数: 9 | 24 poly vinyl imidazole....
AIBN is the initiator...very similar to the ppl in the previous
post.just the ratio of initiator to monomer is far higher than
that(solution polymerization)..
Thanks! |
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z*******g
发帖数: 9 | 25 你是说假设我的引发剂量相对单体同样很高的情况下，也是bulk polymerization得到
搞分子量的？
我的这片文献说他们的bulk得到的分子量只有7000呀。。。这分子量应该很低了。可是
他们用的
就是bulk呀。我用过solution的（单体对引发剂量都是一样的），得到分子量绝对超过
10万。
到底是怎么回事的。。。 |
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z*******g
发帖数: 9 | 26 Yeah,maybe I should ask.....Shouldn't be fake one,though.
The literature is Anal.Chem.1993,65,3512-3517
Something about the PVI is like this:
....Bulk polymerization of PVI was carried out by heating 6ml of
1-vinylimidazole and 0.5g of AIBN at 70oC for 2h under Ar.A dark yellow
precipitate formed soon after heating.After the reaction was allowed to
cool,the precipitate was.....(purification)....The molecular weight of the
polymer was found,by HPLC analusis using a Synchrom Catsec300 column with |
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t***m
发帖数: 114 | 27 Polymere Abbreviations
ABA Acrylonitrile butadiene acrylate
ABS Acrylonitrile butadiene styrene
ABS alloys ABS alloys
ACM Acrylic acid ester rubber
ACS Acrylonitrile chlorinated PE styrene
AES Acrylonitrile-ethylene/propylene-styrene rubber
AMMA Acrylonitrile methyl methacrylate
AN Acrylonitrile
AO Antioxidant
APET Amorphous polyethylene terephthlate
APP Atactic polypropylene
ASA Acrylonitrile styrene acrylate
ASA alloys ASA/PC, ASA/AES etc
ATH Aluminum trihydrate
AZ(O) Azodicarbonamide
BDS Buta |
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s****u
发帖数: 19 | 28 我想在实验室里用polymerization的方法合成polypropylene. 有没有可能？？设备的成
本要多少？危险吗？因为我想应该是在气态下进行反应，压强较大！！！ |
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b**s
发帖数: 589 | 29 关键字: propylene polymerization
你想做聚合研究呢还是只想要一点PP
催化剂: Z-N, 和metallocene
氢气: 调节分子量，一般不必
高压： 提高产率
其实随便找个瓶子，只要不漏气，保持无氧无水就可以，催化剂溶到甲苯中，通propylen
e，加酒精终止沉淀就行
能
用
的
备 |
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a***n
发帖数: 578 | 30 The theoretical prediction of 3D polymerized C60 can reach only 70% bulk
modulus of diamond. Since even perfect case can only reach 70% toughness, how
can a real system reach that number?
Physical Review Letters -- September 11, 2000 -- Volume 85, Issue 11, pp.
2328-2331
Personally, I believe that so called breakthough news is a hoax.
Poeple nowaday are interested at that materials for its novel electric and
magnetic properties.
Magnetic carbon
NATURE 413 (6857): 716-718 OCT 18 2001
By the way, |
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y****u
发帖数: 50 | 31 is it possible to polymerize the monomer with such simple structure? |
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c****n
发帖数: 134 | 32 the criteria of a living polymerization are really confusing... |
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a***n
发帖数: 578 | 33 what is living polymerization? curious. |
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w******r
发帖数: 43 | 34 Another requirement is faster initiation rate than polymerization rate to get
low polydispersity. |
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m****e
发帖数: 255 | 35 【 以下文字转载自 Chemistry 讨论区 】
发信人: minute (秒秒), 信区: Chemistry
标 题: 防止烯烃 polymerize的stabilizer
发信站: BBS 未名空间站 (Mon Oct 16 19:57:16 2006)
都有那几类？就知道个BHT。
有不同的stabilizer对付不同的聚合方式么？
请哪位高分子的大虾给科普一下。。。。
或者有什么文献可以读？
Thanks.... |
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q***i
发帖数: 170 | 36 【 以下文字转载自 Chemistry 讨论区 】
发信人: quasi (燕双飞), 信区: Chemistry
标 题: Re: Phenol polymerization?
发信站: BBS 未名空间站 (Sun Oct 28 17:37:38 2007)
paper attached. |
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p******4
发帖数: 38 | 37 The problem may be in the monomer. Normally it has the inhibitor in the
vinyl monomers. So it is necessary to purify the monomer from the inhibitor
before the polymerization.
Otherwise email the corresponding author and tell him/her your problem. In
most cases he/she will contact you soon.
Good luck, |
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c*********3
发帖数: 1 | 38 I synthesized this polymer poly(N-vinyl pyrrolidone) through ATRP method
with living polymerization characteristic.
you can contact with me: C*********[email protected] |
|
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w********h
发帖数: 12367 | 40 http://ec2-174-129-233-187.compute-1.amazonaws.com/journals/ijps/si/pbtea.html
Call for Papers
The interdisciplinary field of biomaterials and tissue engineering has been
one of the most dynamic and rapidly expanding disciplines during the past
two decades. Polymeric biomaterials have many advantages because of their
unique tailorability of chemical structures and physical properties,
biodegradability, and feasibility of being fabricated into medical devices
for applications in tissue replacemen |
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S*****n
发帖数: 6055 | 41 SS has Cr, which is a good catalyst for ethylene polymerization. Not sure
whether it works for styrene or not...
a |
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a*i
发帖数: 1652 | 42 I use a precision pump to deliver styrene. The outlet is a metal fitting.
After I found that the metal fitting was totally blocked, I replaced it with
a new one. If I don't purge out styrene, the styrene would polymerize in
the metal fitting. I can see sticky/viscous stuff extruded out from the
fitting initially; after that styrene will come out. If I stop the pump and
start it again after a day, the same thing will happen.
The metal is SS 316. |
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a********c
发帖数: 60 | 43 interesting.
repeat the experiment by soaking your metal fitting in a beaker full of
styrene see if it will polymerize.- it should not.
Then only possibility would be you created a oxygen starving condition
when you pump the St. Additionally, you created high heat.
fitting.
with
in
and |
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d**a
发帖数: 3715 | 44 If my monomer (aromatic compound) has a very poor solubility in THF or
toluene, then how it can be polymerized? |
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d**a
发帖数: 3715 | 45 Thank you for your reply. The monomer is a multi-ring aromatic compound,
very difficult to dissolve in DMF at 80 oC.
I am currently trying a free radically polymerization process. |
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d**a
发帖数: 3715 | 46 en,make sense. Previously this monomer has been successfully copolymerized
with styrene in a molar ratio of 50/50. I will try a living polymerization
to see what will happen. |
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y***k
发帖数: 57 | 48 Dear All:
Would anyone here can help me to find a good capable company in China can do
customer synthesis of polymers by using anionic polymerization?
Thanks a lot in advance! |
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y***k
发帖数: 57 | 49 No one answer?
Update: Company with experience in ATRP polymerization is also OK. |
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m*****e
发帖数: 1506 | 50 ATRP cannot directly polymerize methacrylic acid, although there are reports
about aqueous ATRP of sodium methacrylate. And the control is not as good
as traditional ATRP. |
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