Poly[3]rotaxane : Synthesis and Property of The Novel Polymer

本研究采用可逆共价键断裂法合成了新型聚合物聚[3]轮烷，并对其性质进行了研究。通过巯基-二硫键交换反应，设计了一个哑铃型分子，其上含有两个仲铵基团，末端含有两个大体积基团。哑铃分子和具有两个二苯并-24-冠-8-醚部分的间苯二甲酰二酰胺的混合物用催化量的苯乙醚处理，得到65%产率的Mn为25000的聚[3]轮烷。考察了聚合物组分的结构、溶剂、催化剂及浓度对聚合反应的影响。当使用具有较长烷基链的轴组分时，聚合反应缓慢，需要长得多的反应时间（超过1周）才能达到平衡。然而，所得聚合物的分子量高于来自较短烷基链衍生物的分子量， ...更多信息 这可能是由于轴和轮两种单体的1：1加成物的形成受到抑制。通过TGA和DSC分析，测得玻璃化转变温度和5%失重温度分别为140℃和330℃。以三苯基膦-水体系作为二硫化物的典型还原体系，对聚[3]轮烷进行处理，回收了相应的哑铃形（硫醇）和同配位冠醚（轮分子）的还原形式，表明聚[3]轮烷具有循环利用的性质，并将聚[3]轮烷的合成方法推广到相应的网状聚合物聚轮烷网络。用聚冠醚代替同二位冠醚，形成不溶于溶剂的凝胶材料，该凝胶材料通过与哑铃分子反应而在DMF中充分溶胀。凝胶聚合物作为聚轮烷网络在干燥时是半透明的，但在DMF中溶胀时是透明的。通过改变单体投料比、单体浓度、溶剂等条件，可以控制弹性溶胀凝胶的性能

The present research has been carried out to study the synthesis and property of novel polymer "poly[3]rotaxane" by using protocol of reversible covalent bond cleavage. A dumbbell molecule was designed as an axle component which contained two secondary ammonium moieties on it and two bulky groups at the termini, by using thiol-disulfide interchange reaction. A mixture of the dumbbell molecule and a isophthaloyl diamide possessing two dibenzo-24-crown-8-ether moieties was treated with a catalytic amount of benzenethiol to give 65% yield of poly[3]rotaxane with Mn 25000. The effects of the structures of the components, solvent, catalyst, and concentration on the polymerization were studied in detail. When the axle component having longer alkyl chain was employed, the polymerization was sluggish to require much longer reaction time (more than 1 week) to reach the equilibrium. However, the molecular weight of the resulting polymers were higher than that from shorter alkyl chain derivative, … More probably because of the suppression of the formation of 1:1 adduct of the two componets, i.e. the axle and wheel monomers.Thermal analyses and decomposition of poly[3]rotaxane were examined. Glass transition temperature and 5% weight loss temperature were 140℃ and 330℃, respectively, as determined by TGA and DSC analyses. Poly[3]rotaxane was treated with triohenylphosphine-water system as a typical reducing system for disulfide, and the corresponding reduced form of the dumbbell (a thiol) and the homofitopic crown ether (the wheel molecule) as the starting materials were recovered, suggesting the recycling property of poly[3]rotaxane.The synthetic method of poly[3]rotaxane was extended to the corresponding network polymer, polyrotaxane network. Poly(crown ether) was used instead of the homoditopic crown ether resulted in the formation of solvent-insoluble gel material which was well swelled in DMF by the reaction with the dumbbell molecule. The gelled polymer as polyrotaxane network was translucent when dried but transparent when swelled in DMF. The property of the elastic swelled gel was controllable by changing the conditions, monomer feed ratio, concentration, solvent and so on Less