排序方式: 共有40条查询结果,搜索用时 15 毫秒
1.
Polymer networks in which poly(propylene imine) dendrimers (Astramol?) are connected to each other by linear polytetrahydrofuran (polyTHF) segments, were prepared by two methods. The first method was a one‐step procedure in which bifunctionally living polyTHF, obtained by initiation of the THF polymerization with trifluoromethane sulfonic anhydride (triflic anhydride), was reacted with an amino‐dendrimer. This reaction was very fast but did not allow formation of the end products. The second method was a two‐step procedure. In a first step, living polyTHF, prepared with acryloyloxybutyl triflate as initiator, was grafted on an amino‐dendrimer, to form a star‐like, acrylate‐terminated polyTHF multi‐macromonomer with the dendrimer as core. In a second step, networks were obtained by Michael addition between the acrylate end‐groups and unreacted amino‐groups of the dendrimer. This cross‐linking reaction occurred spontaneously upon heating of the solution of the multi‐macromonomer with gelation times varying from a few minutes to a few hours, depending on the temperature and the composition of the prepolymers. With this method it was possible to prepare networks in the form of coatings or films. © 2003 Society of Chemical Industry 相似文献
2.
聚四氢呋喃及其下游产品的开发应用 总被引:2,自引:0,他引:2
本文论述了聚四氢呋喃技术进展、氨纶弹性纤维发展现状和国内外聚四氢呋喃产能和需求。 相似文献
3.
游利锋 《河南纺织高等专科学校学报》2012,(1):39-45
在低浓度杂多酸催化条件下,利用环氧氯丙烷为促进剂、水为分子链调节剂对四氢呋喃进行开环聚合,得到了最终产物聚四氢呋喃.研究了四氢呋喃开环聚合的反应机制,并采用IR,GPC,DSC,TG及SEM等方法对聚合产物进行了表征.与国外进口的样品对比,聚合产物具有预期的分子结构,相对分子质量可控制在2 000左右且分布也较窄,还具有优良的热稳定性及均一性. 相似文献
4.
5.
聚四氢呋喃催化合成研究进展 总被引:2,自引:0,他引:2
主要论述和归纳了目前文献报道的能够催化四氢呋喃开环聚合的各类催化体系,并对不同催化体系的优缺点进行了评述 相似文献
6.
Living polytetrahydrofuran (pTHF) was terminated with the potassium salt of pyrrole to yield polymers with pyrrole end groups. Copolymerization of THF and pyrrole with short and long pTHF segments was achieved by constant potential electrolysis. Syntheses of the block copolymers were performed using tetrabutylammonium tetrafluoroborate, sodium perchlorate, and sodium p‐toluenesulfonate as the supporting electrolytes. Characterization of the block copolymers were based on scanning electron microscopy, differential scanning calorimetry, thermal gravimetry analysis, cyclic voltammetry, and FTIR studies. No significant effect of the chain length on the properties of the copolymers was observed; however, use of different dopants resulted in different thermal and electrochemical behaviors, surface morphologies, and conductivities. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 713–720, 1999 相似文献
7.
8.
The reactions of mono- and difunctional tertiary amine ended polybutadienes with mono- and difunctional living cationic poly THF have been studied. It is shown that the reaction to form quaternary ammonium linking groups takes place rapidly in all cases, and AB. ABA, BAB and (AB) block copolymers have been prepared. The efficiency of the process is extremely high and the degree of conversion is essentially controlled by the efficiency with which the terminal tertiary amine groups can be introduced on to the polybutadiene. The block copolymers show anomalous behaviour on gel permeation chromatography columns and this has been related to a specific interaction of the created ionic groups with polar species on the column packing. This effect is greatest with (AB) block copolymers where substantial proportions are retained indefinitely on the columns. 相似文献
9.
10.
Living polytetrahydrofuran (PTHF) was terminated with sodium thiophene methonate to yield a polymer with a thiophene group at one end. Copolymerizations of PTHF with pyrrole and thiophene were achieved in water‐p‐toluene sulfonic acid and acetonitrile‐tetrabutylammonium tetrafluoroborate (TBAFB) solvent‐electrolyte couples via constant potential electrolyses. Characterizations of the samples were performed by NMR, cyclic voltammetry, FT‐IR, thermal analyses, and scanning electron microscopy. Electrical conductivities were measured by the four‐probe technique. PTHF/PTh film that was deposited on ITO‐glass in a dichloromethane‐TBAFB solvent‐electrolyte couple was found to exhibit electrochromic behavior and it electrochemically switches between blue oxidized and red reduced states. Optical analyses were carried out to investigate the electronic structure of PTHF/PTh electrochromic copolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1014–1023, 2005 相似文献