刚性大分子活化剂阴离子接枝PA6的制备与性能

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1、湖南大学博士学位论文刚性大分子活化剂阴离子接枝PA6的制备与性能姓名：刘耀驰申请学位级别：博士专业：化学工程与技术指导教师：徐伟箭20080415刚件人分予活化剂阴离了接枝PA6的制备与性能采用DSC、XRD、SEM、TG及平衡吸水试验，对不同接枝率的聚合物的玻璃化转变、结晶形态与结晶度、热性能、平衡吸水量及断面形态等进行了研究。刚性聚合物在PA6基体内的分散均一。增大刚性聚合物含量，接枝聚合物的T。值升高，而Tm和结晶度降低。均匀分布于PA6基体内的刚性聚合物使得PA6链段的运动受阻，扰乱PA6分子链规整有序的排列、结晶的完善程度下降。与PS

2、和PMMA接枝共聚可以明显降低PA6的吸水率、提高PA6的尺寸稳定性。当PS含量为l8．3％时，PS．g．PA6的吸水量由纯PA6的4．8％降低至1．9％；PMMA含量为19．9％时，共聚物PMMA．g．PA6的吸水率降至2．1％。与PS和PS．alt．NPMI接枝可以提高PA6的热稳定性。当PS含量为18．3％时，PS．g．PA6的Td值比纯PA6高出450C；PS．alt．NPMI含量为7．2％～20％、热失重20％时，共聚物的热降解温度提高了400C～600C。PS和PS．alt—NPMI降低了共聚物低温区的降解速率，起到了保护PA6基体

3、的作用。但是，受PMMA易于热分解的影响，PMMA．g．PA6在275℃后出现了明显的降解。关键词：刚性聚合物单体浇注聚酰胺6接枝大分子活化剂阴离子聚合性能博卜学位论文ABSTRACTTheusageofpolyamide6(PA6)islimitedbysomedrawbacks，suchashighmoistureabsorption，lowdimensionalstabilityandlowthermaldegradationtenlperature．ThemodificationoflinearI?A6obtainedbyhydroly

4、ticpolymerizationsof￡一caproIactam(CL)caneasilybemodi行edbyphysicalblendingorreactiVecompatibilization．Blendsbetweenlinearpolyamide6andrigidpolymers，suchaspolystyrene(PS)，poly(methylmethacrylate)(PMMA)andpolyimide(PI)，arenowreadilyaVailable．ReactiVeandnonreactiVecompatibilizat

5、ions，howeVer，arenotpracticableforthemodincationofmonomercastingpolyamide6(MCPA6)preparedbyanionicpolymerizationofCL，whichcommonlyresultsinacrosslinkedandstructuralirregularpolymerbecauseofClaisen—typecondensationsandothersidereactions．DuringtheanionicpolymerizationofCL，anact

6、iVatoriscommonlyaddedtospeeduptheactivationstep．Therebyf．unctionalizedMCPA6canbepreparedbychemicallymodifyingactiVators，i．e．，byfunctionalizedmacroactiVators．Premadepolymerswithpendantsofestersandimideswereusedasthefunctionalizedmacroactivators．ThesependantsreactedwithCLstofo

7、rmN—carbamatedcaprolactam(CCL)moieties，fromwhichPA6chainsgrew．HoweVer，theactiVationcapacitiesofestersandimidesarerelativelylow．Thetimenecessaryforthecompletionofpolymerizationislonger(morethantwohours)thanthemeanresidencetimeofatypicalMCPA6(afewminutes)．Inthispaper，CCLpendan

8、twasincorporatedintoPS，PMMAandpoly(styrene—alt-N—phenylmaleimide)(PS-alt—NP