改性尼龙6结晶动力学的研究

DissertationSubmittedtoHebeiUniversityofTechnologyForTheMasterDegreeofChemistryandPhysicsofPolymersSTUDYOFTHECRYSTALLIZATIONKINETICSOFTOUGHENEDNYLON6byLiuXinranSupervisor:Prof.QuXiongweiMarch2012*A~.~~:m~~~~~~~,~*A~~~m~T,*~~~I~m~1~Ef.JJJX;*0~i)(t:pB~ffIJ)j']IfflEf.JI*J?@:7r,*~1fLi1?;)(/f'E11t1ffriJ1mAQX;~1*B~~~~*~I*J?@:,&/f'E11t*A~a~~~~~w~ffltt~~M.~*~)(m~&Ef.J~~I*.Wfi.~~~~AQX;~1*,~B~)(~~.~~~~o*[-,~~~)(~~tt~~~~~.ff~*A~mo*A7t~7M¥nr~tI!lt*~~Tr&~,f*1f,~ffl~1fLi1?;)((fJ~rm5E:~tstff~*ffl~,.~,~~,.*~QX;~~¥~f*1f~)(;~tstff«.~*~Q~)(~)(~~$~I*J?@:~~mW*;~tstff~~~Q~)((fJ~.QX;.~I*J?@:.Aff~.MW*:fr~~,~mt;~tstff~!f:i][E~ff~.f1llX;~~JL~*3ti~)(aJ][~{tf=*rHt1.:r1t&o(f**~~Q~)(~M*fr5i§:ffl*tt«iJG~)j河北工业大学硕士学位论文 i 改性尼龙6结晶动力学的研究摘要尼龙6属于结晶性聚合物，分子链结构及结晶条件不同，其结晶速度会有很大的差别，进而影响材料的结晶形态和结构，在宏观上表现为材料力学性能和热性能的差异。因此，聚合物结晶动力学的研究，有助于控制结晶过程，改善制品性能，对于聚合物的加工和应用具有重要的理论和现实意义。加入ACR增韧改性剂后，两组分之间的相互作用会对尼龙6基体的结晶性能产生一定的影响，进而影响材料的宏观性能。本文采用差示扫描量热仪(DSC)研究了尼龙6(PA6)及其共混物的结晶行为。研究了壳层功能单体丙烯酸(AA)和甲基丙烯酸(MAA)的用量以及粒径的变化对尼龙6结晶动力学的影响；通过Hoffman-Weeks方程计算出了尼龙6及其共混物的平衡熔点，同时用Avrami方程分析了PA6及其共混物的等温结晶动力学，然后计算了相关的结晶动力学参数。结果表明：共混物的Avrami指数n值介于3-4之间，表明尼龙6共混物是三维球晶生长的球状晶体；乳胶粒子PBMA/PBMMA的加入对尼龙6基体起到了成核剂的作用，影响到PA6成核机理和结晶的生长，且明显改变了尼龙6的结晶行为，使尼龙6的结晶速率增加，更易于结晶。利用修正Avrami方程的Jeziorny法、莫志深法和Kissinger方程对其动力学过程进行了分析。结果表明：由于功能单体的加入起到成核剂的作用，使晶核的生成变快，提高了尼龙6的成核速率。同时，在研究其结晶活化能时发现由于功能单体丙烯酸(AA)和甲基丙烯酸(MAA)的加入起到了诱导结晶的作用，降低了尼龙6的结晶活化能。采用偏光显微镜观察了尼龙6及共混物的非等温结晶行为，发现增韧组分的加入使得尼龙6球晶尺寸减小。关键词：改性尼龙6；DSC；平衡熔点；结晶动力学；结晶活化能；熔融行为改性尼龙6结晶动力学研究 ii STUDYOFTHECRYSTALLIZATIONKINETICSOFTOUGHENEDNYLON6ABSTRACTNylon6(orpolyamide6,PA6)isawidelyusedengineeringpolymerwhichhashightearandabrasionresistance,andlowfrictioncoefficientprovidingagoodbalancebetweenhighstrength,elasticityandtoughnessdesiredinengineeringapplications.Inthispaper,theisothermalandnon-isothermalcrystallizationkineticsoftoughenedNylon6isinvestigatedbydifferentialscanningcalorimetry(DSC).Theisothermal/non-isothermalcrystallizationbehaviorofNylon6/PBMA[Poly(butylacrylate/methylmethacrylate-co-acrylicacid)]andNylon6/PBMMA[Poly(butylacrylate/methylmethacrylate-co-methacrylicacid)]compositeswasstudiedbydifferentialscanningcalorimetry(DSC).TheAvramiequationandLauritizen-Hoffmanequationwereemployedtoanalyzetheisothermalcrystallizationbehavior.ItwasfoundthattheAvramiequationdescribedtheprimarystageoftheisothermalcrystallizationofNylon6well.Theavramiindexoftheblendsis3~4.TheAvramiequationmodifiedbyJeziornyandMo’sequationwasusedfornon-isothermal.Inthestudyofthenon-isothermalcrystallization,Mo’smethodwasbetterfittinginawiderrangeofcrystallinity.Inaddition,theactivationenergywasalsocalcuatedbyHoffman-WeekequationforisothermalandKissingerequationfornon-isothermalrespectively.Polarizingmicroscopewasemployedtoobservethenon-isothermalcrystallizationofNylon6anditsblends.Theresultindicates:ThefunctionalgrouponthesurfaceoftheCore-Shellparticlesactedasnucleatingagentsduringthecrystallizationoftheblends,whichcanreducethecrystallizationactivationenergy;Ontheotherhand,thefunctionalgroupcanblockmolecularchainmovementduringthecrystallization.KEYWORDS:Toughenednylon6;DSC;Crystallizationkinetics;Crystallizationactivationenergy;Equilibriummeltingpoint;Meltingbehavior河北工业大学硕士学位论文 iii 目录第一章绪论...........................................................................................................................11.1引言..........................................................................................................................11.2聚合物结晶动力学的理论研究...........................................................................21.2.1Avrami方程.....................................................................................................21.2.2聚合物非等温结晶动力学研究--Avrami方程的修正.................................41.3尼龙6结晶动力学研究进展...............................................................................71.4本研究立题依据及研究内容.............................................................................10第二章改性尼龙6的等温结晶动力学研究.................................................................112.1改性尼龙6的制备与测试..................................................................................112.1.1试样制备.......................................................................................................112.1.2等温熔融行为的研究及平衡熔点Tm0的测定............................................122.1.3等温结晶动力学的研究...............................................................................122.2改性尼龙6的等温结晶动力学研究................................................................122.2.1等温熔融行为...............................................................................................132.2.2平衡熔点.......................................................................................................142.2.3等温结晶动力学分析...................................................................................172.3本章小结................................................................................................................27第三章改性尼龙6的非等温结晶动力学研究.............................................................293.1测试样条制备与测试...................................