Single-step synthesis of internally functionalizable hyperbranched polyethers
作者:Raj Kumar Roy、S. Ramakrishnan
DOI:10.1002/pola.26821
日期:2013.10
Radical catalyzed thiol‐ene reaction has become a useful alternative to the Hüisgen‐type azide‐yne click reaction as it helps expand the variability in reaction conditions as well as the range of clickable entities. In this study, the direct generation of a hyperbranched polyether (HBPE) having decyl units at the periphery and a pendant allyl group on every repeat unit of the polymer backbone is described;
Hyperbranched Copolymers versus Linear Copolymers: A Comparative Study of Thermal Properties
作者:Girish Ch. Behera、Animesh Saha、S. Ramakrishnan
DOI:10.1021/ma0508146
日期:2005.9.1
varied linearly with monomer composition, confirming the formation of truly random copolymers. Analogous linearcopolymers based on suitably designed AB-type monomers, containing the same two spacers, were also prepared for comparison. Thermal analysis of these copolymers using DSC indicated that the Tg's of both linearcopolymers and hyperbranchedcopolymers varied with composition in a manner that was
结合了具有相似长度但具有不同柔性的间隔片段的两种AB 2型单体的共聚合,首次允许制备一系列高支化共聚物,其中,在保持相似支化密度的同时,改变了骨架的刚性。该共聚物是通过最近开发的熔体互醚化方法制备的,以生产分子量范围为20000至50000的中等分子量的聚合物。11 H NMR光谱研究表明,共聚物的组成随单体组成线性变化,证实了真正无规共聚物的形成。还准备了基于适当设计的AB型单体的类似的线性共聚物,其中包含相同的两个间隔基,以进行比较。使用DSC对这些共聚物进行的热分析表明,线性共聚物和超支化共聚物的T g均以完全符合Fox方程的方式随组成而变化,尽管所有线性共聚物均表现出明显更高的T g的价值高于他们的超支部门。有趣的是,尽管它们的拓扑结构非常不同且存在大量的链端,但超支化共聚物的T g变化与线性类似物相似。在高支化共聚物(例如具有不同支化密度和末端官能度的那些)的更广泛上下文中,这种观察的普遍性仍有待测试。
Thiol-ene clickable <i>hyperscaffolds</i>
bearing peripheral allyl groups
作者:Raj Kumar Roy、S. Ramakrishnan
DOI:10.1002/pola.24597
日期:2011.4.15
that the kinetics of polymerization is not dramatically affected by the change of the ether unit from previously studied methyl benzyl ether to an allyl benzyl ether. The peripheral allyl groups were readily clicked quantitatively, using a variety of thiols, to generate an hydrocarbon‐soluble octadecyl‐derivative, amphiphilic systems using 2‐mercaptoethanol and chiral amino acid (N‐benzoyl cystine) derivatized