c*s
发帖数: 2145 | 1 once AIBN decompose to release radicals, it will be trapped by CTA and this
is the basis for raft. |
|
d*****i
发帖数: 77 | 2 Thanks.
But it won't be released any more?
this |
|
|
|
d*****i
发帖数: 77 | 5 关键是用的AIBN和polymer-CTA比是2：1啊！
是因为polymer比AIBN的残留基团更容易离去吗？ |
|
b******0
发帖数: 45 | 6 为什么加这么多AIBN？
和反应温度有关，AIBN和polymer-CTA比是2：1，也未必结果不好。
styrene 温度高的话，不需要引发剂也行。
反应控制不好，可能有些其它中止的PS均聚物。试试沉淀在cyclohexane里，或者用
cyclohexane洗掉PS均聚物 |
|
b*****y
发帖数: 40 | 7 我一般用的是0.05：1 到 0.2：1，这么大量的还第一次听说
那反应温度和时间呢？实际有多少AIBN裂解了呢？你看到的是那篇文献？ |
|
t****1
发帖数: 232 | 8 Depends on your ester group... I have experience of H-bonding of n-butanol
and methacrylates/acrylates, even the OH group in monomer can form H-bonding
with carbonyl group. |
|
t****1
发帖数: 232 | 9 high temperature might disrupt H-bonding, but 90-100C should be fine. In
order to prove the existance of H-bonding, you can try to do some FT-IR with
the mixture of your monomer and solvents. The carbonyl peak should show up
around 1710cm-1 and there will be a distinctive shoulder upon the peak once
there is H-bonding formed with carbonyl group. For details, you can check my
paper (DOI: 10.1021/ma1009963) |
|
h****z
发帖数: 1996 | 10 除起来不麻烦还是除了吧
或者你告诉大家具体是哪个monomer哪个阻聚剂哪个催化剂 大家也好帮你看看 |
|
m*****e
发帖数: 1506 | 11 这不太容易吧，做AB monomer缩聚？
你用romp单体开出来的FG都是在侧链上的
用cyclooctene开出来FG可以离backbone很近，但还是在侧链 |
|
P********n
发帖数: 372 | 12 有一个recruiter找到我，但是我已经决定不去了，可以推荐合适背景的人试试。公司
在芝加哥附近。
Our client is an emerging company focused on the development of solution-
processable functional materials that are essential to the development of
next generation of electronic display technology.
Having achieved international recognition and reputation, they now have
customer relationships with many of the marquee display companies in the
world and have experienced significant and positive growth.
We are seeking an elite, PhD-level scientist w... 阅读全帖 |
|
w********h
发帖数: 12367 | 13 1 PROG POLYM SCI 24.100
2 POLYM REV 6.281
3 BIOMACROMOLECULES 5.479
4 POLYM CHEM-UK 5.321
5 MACROMOLECULES 5.167
6 MACROMOL RAPID COMM 4.596
7 SOFT MATTER 4.390
8 J POLYM SCI POL CHEM 3.919
9 ADV POLYM SCI 3.890
10 MACROMOL BIOSCI 3.886
11 J MEMBRANE SCI 3.850
12 CARBOHYD POLYM 3.628
13 CELLULOSE 3.600
14 POLYMER 3.438
15 J BIOACT COMPAT POL 2.953
16 POLYM DEGRAD STABIL 2.769
17 EUR POLYM J 2.739
18 REACT FUNCT POLYM 2.479
19 PLASMA PROCESS POLYM 2.468
20 MACROMOL CHEM PHYS 2.3... 阅读全帖 |
|
|
z*****y
发帖数: 7 | 15 Thank you, cds. Would you please show me some references? Thanks in advance! |
|
D********g
发帖数: 533 | 16 CTA只要选对，能compete with monomer to capture radicals.
除氧，freeze-pump cycle最好，开始先这么弄，保证氧除尽，摸条件上轨道以后再试
试通氮气40分钟（取决于你的反应体系有多大）再看看。一般来说通氮气only应该够了。 |
|
z*****y
发帖数: 7 | 17 increase the concentration of the low propagation constant monomer could
work? |
|
b*****y
发帖数: 40 | 18 Has anybody reported the reactivity ratios of these two monomers?
I agree with you that acrylic acid probably is much more reactive than
acrylamide.
One way to circumvent the problem is to copolymerize tert-butyl acrylate
with acrylamide, which might have similar reactivities. Then hydrolyze.
random |
|
C*******b
发帖数: 174 | 19 最好是蒸馏。省事的方法是过一下碱性氧化铝柱子，出去阻聚剂。 |
|
W********2
发帖数: 4008 | 20 补充：
ATRP最好在无水的环境下进行，所以你的原材料如有条件最好在真空中保存 |
|
|
L**i
发帖数: 22365 | 22 过柱子就行
atrp怕氧气
真空管道要密闭，油泵要给力…… |
|
w********h
发帖数: 12367 | 23 1 PROG POLYM SCI 26.383
2 POLYM REV 7.794
3 MACROMOLECULES 5.521
4 BIOMACROMOLECULES 5.371
5 POLYM CHEM-UK 5.231
6 MACROMOL RAPID COMM 4.929
7 J MEMBRANE SCI 4.093
8 SOFT MATTER 3.909
9 MACROMOL BIOSCI 3.742
10 PLASMA PROCESS POLYM 3.730
11 ADV POLYM SCI 3.648
12 J POLYM SCI POL CHEM 3.543
13 CARBOHYD POLYM 3.479
14 CELLULOSE 3.476
15 POLYMER 3.379
16 POLYM DEGRAD STABIL 2.770
17 EUR POLYM J 2.562
18 REACT FUNCT POLYM 2.505
19 MACROMOL CHEM PHYS 2.386
20 MACROMOL MATER ENG 2.3... 阅读全帖 |
|
w********h
发帖数: 12367 | 24 Date: Feb. 6, 2014
FOR IMMEDIATE RELEASE
National Academy of Engineering Elects 67 Members and 11 Foreign Associates
WASHINGTON — The National Academy of Engineering (NAE) has elected 67 new
members and 11 foreign associates, announced NAE President C.D. (Dan) Mote
Jr. today. This brings the total U.S. membership to 2,250 and the number of
foreign associates to 214.
Election to the National Academy of Engineering is among the highest
professional distinctions accorded to an engineer. Academy m... 阅读全帖 |
|
w********h
发帖数: 12367 | 25 Date: Feb. 6, 2014
FOR IMMEDIATE RELEASE
National Academy of Engineering Elects 67 Members and 11 Foreign Associates
WASHINGTON — The National Academy of Engineering (NAE) has elected 67 new
members and 11 foreign associates, announced NAE President C.D. (Dan) Mote
Jr. today. This brings the total U.S. membership to 2,250 and the number of
foreign associates to 214.
Election to the National Academy of Engineering is among the highest
professional distinctions accorded to an engineer. Academy m... 阅读全帖 |
|
d******1
发帖数: 92 | 26 油溶性的 methacrylate monomer
Thanks |
|
d******1
发帖数: 92 | 27 油溶性的 methacrylate monomer
Thanks |
|
p******s
发帖数: 193 | 28 【 以下文字转载自 Chemistry 讨论区 】
发信人: pastoris (锦涛喇嘛), 信区: Chemistry
标 题: 求指教一个纳米fe3o4@sio2@pmma合成中，pmma的聚合条件
发信站: BBS 未名空间站 (Tue Apr 22 10:27:16 2014, 美东)
想照着2009年邓春晖Angew chemie的Fe3O4@SiO2@PMMA 的文章，做这个东西，用来接功
能蛋白
大家看看，最后的聚合不需要引发剂么？
前文不赘述了，Fe3O4@SiO2-MPS 已经合成好了
要往上面修饰PMMA了，
The sandwich structured Fe3O4@SiO2@PMMA microspheres were synthesized via an
aqueous-phase radical polymerization. Typically, in a three-necked round
bottom flask (100 mL) equipped with a mechanical stirrer, a refluxing
conden... 阅读全帖 |
|
w********h
发帖数: 12367 | 29 Rank Full Journal Title Journal Impact Factor
1 PROGRESS IN POLYMER SCIENCE 26.854
2 BIOMATERIALS 8.312
3 Journal of Biomedical Nanotechnology 7.578
4 Polymer Reviews 6.593
5 MACROMOLECULES 5.927
6 BIOMACROMOLECULES 5.788
7 Acta Biomaterialia 5.684
8 Polymer Chemistry 5.368
9 ACS Macro Letters 5.242
10 JOURNAL OF MEMBRANE SCIENCE 4.908
11 EUROPEAN CELLS & MATERIALS 4.887
12 Advanced Healthcare Materials 4.880
13 MAC... 阅读全帖 |
|
r********4
发帖数: 97 | 30 Special Issue for International Journal of Polymer Science
各位学高分子的朋友， 看看有没有相关研究方向的文章考虑submit...
http://www.hindawi.com/journals/ijps/si/672671/cfp/
Functional Polymer Materials from Natural and Sustainable Resources
Call for Papers
Functional polymers represent a class of materials with advanced chemical,
physical, and biological properties, which have found broad uses in both
industry and people’s daily life, including semiconducting materials,
stimuli-responsive materials, and biomimetic mater... 阅读全帖 |
|
发帖数: 1 | 31 本人多年从事polymer chemistry, organometallic, nanomaterials的研究工作，最近
在展审稿数量申绿，求推荐。以下是我的研究领域：
• Strong proficiency in design multi-step organic/organometallic/
inorganic syntheses under the various conditions, design of synthetic
strategy based on goal compound, cultivation of single crystals, synthesis
and characterization of organometallic compounds (Pd, Al, Sc, Y, Ti, Zr, Hf,
Fe, Co, Ni, Cr, Ir, Ru), macromolecules and nanomaterials:
1. Cross-Coupling polymerization: design, synthesis an... 阅读全帖 |
|
发帖数: 1 | 32 本人多年从事polymer chemistry, organometallic, nanomaterials的研究工作，最近
在展审稿数量申绿，求推荐。以下是我的研究领域：
• Strong proficiency in design multi-step organic/organometallic/
inorganic syntheses under the various conditions, design of synthetic
strategy based on goal compound, cultivation of single crystals, synthesis
and characterization of organometallic compounds (Pd, Al, Sc, Y, Ti, Zr, Hf,
Fe, Co, Ni, Cr, Ir, Ru), macromolecules and nanomaterials:
1. Cross-Coupling polymerization: design, synthesis an... 阅读全帖 |
|
p******e
发帖数: 164 | 33 could you supply some "BASIC" literature for in-situ polymerization of CNT
in monomers? I am writing several papers on this topic, don't want to be
critisized by you later, haha... |
|
A***N
发帖数: 219 | 34 谢谢~~~
自我介绍一下。我是Master，现在做的是关于火焰合成碳纳米管的课题。和大家比较不
一样的是我不用纯的fuel（比如H2，CO，methane，ethane，etc）。而是先将聚合物（
比如polyethelene, polystyrene）裂解，获得monomer，dipolymer或multimer之后通入氧气燃烧，
从而获得CO，H2等大家认为可以用来生成碳纳米管的gas source。 |
|
d***g
发帖数: 9 | 35 很多年轻人到美国都想要申请大学的护士专业，也就是英文所说的Nursing，因为几乎
每个人都说护士可以在美国申请到绿卡，可以赚年薪起薪6万，那为什么有人说简单，
有人说复杂，这其中究竟有什么诀窍呢？
那么下面整个介绍一下在美国做护士的步骤，以及申请绿卡的条件。
这篇文章会介绍几个部分的内容，
包括：
1 申请护士职业移民最基本的条件和优点。
2国内护士专业毕业，人在美国，或人不在美国，如何申请美国大学的护士专业或申请
护士执照考试和如何进行职业规划。
3国内高中毕业，有高中毕业文凭，人在美国，如何申请美国大学的护士专业。
4国内大专或本科毕业（非护士专业），有高中和大学文凭，如何申请美国大学的护士
专业。
5 已经有身份（有绿卡或是美国公民），但是想申请护士专业，如何申请美国大学的护
士专业。
6 通过考试后，取得美国护士执照，通过托福考试后，如何找医院面试谈判，如何找律
师递交移民申请，如何关注职业移民配额，最终申请绿卡。
7 注册护士考试的英文名称和考试内容，那里可以买参考书，网上有哪些资源。
8 申请过程中常见的困难和困扰有那些
9 托福考试的复习与报考准备
10 附录 护士注册... 阅读全帖 |
|
n****n
发帖数: 492 | 36 polymer 由 monomers 间形成共价键构成
蛋白质，核酸，多糖都算 polymer
但这些 polymer 的分子量要高于一定标准 (few thousand daltons?)
才算 macromolecule |
|
a*****y
发帖数: 361 | 37 【 以下文字转载自 Whisper 讨论区 】
【 原文由 aimerfy 所发表 】
发信人: space (排骨教主), 信区: Whisper
标 题: 关于DNA的弹性---by space(供讨论)
发信站: The unknown SPACE (Tue Feb 1 23:21:18 2000), 转信
DNA的弹性. 不对头的地方大家指点一下啊. 这些东西可能3.24号会有人提问.偶
还不如先演习一下...
DNA的双链结构,可以数出来和整体力学性质有关系的相互作用大概有下面几种:
1. 单链是带电的. 单链作为一个polymer, 每个monomer之间的相互作用是共价键
作用. 和共享电子有关系,所以作用强度在一个电子伏特量级;
2. 碱基之间的作用构成碱基对, 这个作用是氢键作用, 量级小很多,是KT量级;
3. 碱基对之间还有所谓堆栈作用, 也是在KT量级.
所以拉扯DNA, 想把backbone拉断很不容易. 但是打开双链,或者拉直DNA需要的力气就小
很多.
DNA的力学性质就由这几个作用共同决定了.
现在比如把DNA一端固定,拉另外一端. 假设总长度(co |
|
i****k
发帖数: 236 | 38 Estimated Life Expectancy Chart
The following chart details the predicted life expectancy of household
materials and components.
Interior and exterior paints can last for 15 years or longer, however
homeowners often paint more frequently. Surface preparation is likely the
most important determiner of paint life expectancy.
ADHESIVES, CAULK AND PAINTS YEAR
Caulking 5-10
Paint 7
Roofing Adhesives 15+
Appliance life expectancy depends to a great extent on the use it receives.
F... 阅读全帖 |
|
