官能化聚四氢呋喃-b-聚异丁烯-b-聚四氢呋喃三嵌段共聚物的合成与性能  

Synthesis and Property of Novel Functionalized Polytetrahydrofuran-b-polyisobutylene-b-polytetrahydrofuran Triblock Copolymers

作　　者：张方[1] 张航天[1] 杨甜 孔波 郭安儒[1] 章琦 吴一弦[1] Fang Zhang;Hang-tian Zhang;Tian Yang;Bo Kong;An-ru Guo;Qi Zhang;Yi-xian Wu(State Key Laboratory of Chemical Resource Engineering,Beijing Laboratory of Biomedical Materials,Beijing University of Chemical Technology,Beijing 100029)

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室生物医用材料北京实验室

出　　处：《高分子学报》2020年第1期98-116,I0004,共20页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51521062,21574007)资助项目

摘　　要：采用2-氯-2,4,4-三甲基戊烷或对二枯基氯为引发剂和TiCl4或FeCl3为共引发剂,引发异丁烯(IB)可控/活性正离子聚合与官能端基转化,设计合成不同分子量及窄分子量分布的端基官能化聚异丁烯,如双端烯丙基溴官能化聚异丁烯(Br-PIB-Br)或双端烯丙基胺官能化聚异丁烯(H2N-PIB-NH2).采用烯丙基溴/高氯酸银体系引发四氢呋喃(THF)开环聚合,合成聚四氢呋喃活性链(PTHF+).进一步通过将IB可控/活性正离子聚合与THF可控/活性正离子开环聚合2种方法相结合,设计合成2种新型官能化聚四氢呋喃-b-聚异丁烯-b-聚四氢呋喃(PTHF-b-PIB-b-PTHF)三嵌段共聚物:(1)以上述Br-PIB-Br为大分子引发剂,在AgClO4作用下引发THF活性正离子开环聚合,采用水终止活性链端,设计合成双端为羟基的HO-PTHF-b-PIB-b-PTHF-OH三嵌段共聚物(简称:FIBF-OH);(2)以上述合成的PTHF+活性链与H2NPIB-NH2链端胺基发生高效亲核取代反应,设计合成中间链段连接点含―NH―官能基团的PTHF-b-HNPIB-NH-b-PTHF三嵌段共聚物(简称:FIBF-NH).在上述三嵌段共聚物中,极性PTHF链段与非极性PIB链段的热力学不相容,导致其呈现明显的微相分离,且微观形态与共聚组成相关.PTHF均聚物易结晶,在上述共聚物中由于PTHF链段单端受限致其结晶性减弱.三嵌段共聚物分子链的中间连接点含―NH―官能基团,具有更强的氢键作用,促进PTHF链段重排并结晶,易形成更紧密的超分子网络结构,导致即使在PTHF链段相对分子量为0.7 kg·mol^-1时仍具有较强的结晶性,且结晶熔融温度明显提高.此外,由于FIBF-NH中形成超分子网络结构,使材料具有优异的自修复性能,材料表面的切痕在常温下10 min后可以完全自愈合.本文设计合成的新型官能化PTHF-b-PIB-b-PTHF三嵌段共聚物兼具有PTHF与PIB的优良性能,在生物医用、智能修复等功能材料领域具有潜在的应用前景.The functionalized polyisobutylenes(PIBs)carrying allyl-Br or allyl-NH2 with different molecular weights and narrow molecular weight distribution,could be successfully synthesized via controlled/living cationic polymerization of isobutylene(IB)in n-hexane/CH2Cl2 mixed solvents at-80℃.Controlled/Living cationic ringopening polymerization(ROP)of tetrahydrofuran(THF)was achieved with Allyl-Br/AgClO4 initiating system at 0℃.Two kinds of novel functionalized PTHF-b-PIB-b-PTHF triblock copolymers were designed and synthesized via combination with controlled/living cationic polymerization of IB and controlled/living cationic ROP of THF.Terminal hydroxyl functionalized HO-PTHF-b-PIB-b-PTHF-OH triblock copolymers(expressed as FIBF-OH)were successfully synthesized by using the PIBs with difunctional allyl-Br terminal groups(Br-PIB-Br)as macroinitiators to initiate living cationic ROP of THF in the presence of AgClO4 to create living PTHF+-b-PIB-bPTHF+chains and then terminating by H20 molecules.On the other hand,PTHF-b-HN-PIB-NH-b-PTHF triblock copolymers containing hydrogen bonds at the connection point of PTHF and PIB segments(expressed as FIBFNH)were also successfully synthesized via efficient nucleophilic substitution reaction between living PTHF+chains and amine groups in H2 N-PIB-NH2.Due to the dynamic incompatibility between polar PTHF segments and nonpolar PIB segments and the crystallization of PTHF segments,PTHF-b-PIB-b-PTHF triblock copolymers exhibit an obvious microphase separation micromorphology.It is recognized that the chemical structure in the PTHF-b-PIB-b-PTHF triblock copolymers makes a great contribution to the formation of hydrogen bonding and thus the supramolecular network.The crystallization of PTHF segments could be improved even in FIBF-NH with relatively short PTHF segments,e.g.Mn,PTHF=0.7 kg·mol^-1.FIBF-NH could be completely self-healing at 25℃ for 10 min after cutting on its surface.However,the cutting on FIBF-OH surface was difficult to heal even at 30℃ for 3 days.Moreover,the PTHF-

关 键 词：聚异丁烯 聚四氢呋喃 嵌段共聚物 正离子聚合 超分子网络 

分 类 号：TQ317[化学工程—高聚物工业]