CAJ | 학술논문

研究了以二元环状仲胺哌嗪（PPZ）替代二元伯胺作为扩链剂,以六亚甲基二异氰酸酯（HDI）为偶联剂,以端羟基聚（丙交酯-co-对二氧环己酮）（HO-P（LA-co-PDO）-OH）为软段,采用溶液法合成了一系列新型聚氨酯脲（P（LA-co-PDO）-PPZ-PUU）。1 HNMR表征结果证实了P（LA-co-PDO）-PPZ-PUU的结构。比较了以PPZ和BDA为扩链剂时两反应体系的粘度变化,产物在氯仿中的溶解性、热熔性及其玻璃化转变温度（Tg）随NCO/OH摩尔比的变化。同时研究了其形状记忆性能。结果表明,PPZ反应体系的粘度更低,产物的溶解性和热熔性更好,PPZ可明显减少交联;而且,PPZ的环状结构可明显提高PUU硬段的刚度,从而提高Tg。形状回复时间受温度的影响,回复温度越高,形状回复时间越短。该材料呈现良好的形状记忆性能且形状回复率均可达到95%以上。
연구료이이원배상중알고진（PPZ）체대이원백알작위확련제,이륙아갑기이이청산지（HDI）위우련제,이단간기취（병교지-co-대이양배기동）（HO-P（LA-co-PDO）-OH）위연단,채용용액법합성료일계렬신형취안지뇨（P（LA-co-PDO）-PPZ-PUU）。1 HNMR표정결과증실료P（LA-co-PDO）-PPZ-PUU적결구。비교료이PPZ화BDA위확련제시량반응체계적점도변화,산물재록방중적용해성、열용성급기파리화전변온도（Tg）수NCO/OH마이비적변화。동시연구료기형상기억성능。결과표명,PPZ반응체계적점도경저,산물적용해성화열용성경호,PPZ가명현감소교련;이차,PPZ적배상결구가명현제고PUU경단적강도,종이제고Tg。형상회복시간수온도적영향,회복온도월고,형상회복시간월단。해재료정현량호적형상기억성능차형상회복솔균가체도95%이상。
Piperazine （PPZ） was used a chain extender to synthesize a series of novel poly（urethane-urea）（PUU） with poly（lactide-co-p-dioxanone） macrodiol （HO-P（LA-co-PDO）-OH） as a soft segment and hexam- ethylene diisocyanate （HDI） as a coupling agent. PPZ, as a cyclic secondary diamine is expected to reduce or even eliminate the crosslinking during the synthesis of PUU which is often happened when those primary diam- ines are used as chain extenders. Moreover, the cyclic structure of PPZ may be helpful to enhance the rigidity of the hard segments in the PUU. NMR was employed to verify the chemical structures of the PUU copolymers. The phenomenological observations on the reaction mixture and the solubility and melting state of the produced PUU confirmed that PPZ may significantly reduce the crosslinking compared to butanediamine （BDA） as a chain extender. Finally, the effects of the hard segment contents characterized by NCO/OH molar ratios on the Tg values of PUU were investigated by means of differential scanning calorimetry （DSC）, and the results revealed that Tg values can be controlled from 3？. 32 to 43.50℃ by increasing the NCO/OH ratios from 1.1 to 1.5 and the cyclic structure of PPZ increases the rigidity of the hard segments and thereby the Tg values. PUU had good shape memory properties：shape recovery ratio was more than 95 %.