PETPTT共混体系的相容特性及力学性能研究.docx

PETPTT共混体系的相容特性及力学性能研究
摘要：
本文研究了PET和PTT共混体系的相容性和力学性能。通过扫描电子显微镜（SEM）、差示扫描量热法（DSC）、拉伸测试和环境应力裂纹扩展测试等手段，分析共混体系的相互作用及其对力学性能的影响。结果表明，PET和PTT在一定比例下可形成相容的共混体系，共混体系的熔融温度和熔体黏度均比单组分高，拉伸强度和断裂伸长率也随PET含量的增加而增加。此外，PET/PTT共混体系在裂纹扩展方面表现出与单组分PTT相似的特性。本研究为PET/PTT共混体系的应用提供了理论依据和参考。
关键词：PET、PTT、共混体系、相容性、力学性能
Introduction
PET(Polyethyleneterephthalate)andPTT(Polytrimethyleneterephthalate)aretwocommonlyusedengineeringthermoplasticsduetotheirexcellentmechanicalpropertiesandchemicalresistance.PEThasgooddimensionalstability,highstrengthandstiffness,andiswidelyusedinpackaging,engineeringplastics,andtextilefibers.PTThasexcellentelasticity,lowshrinkage,andgooddyeability,makingitsuitableforhigh-performancefabricsandfibers.However,thetwopolymershavedifferentpropertiesandmolecularstructures,whichlimitstheircompatibilityandblendingatamolecularlevel.Therefore,itisofgreatsignificancetostudythecompatibilityandmechanicalpropertiesofPET/PTTblends.
Experimental
Materials:PET(Intrinsicviscosity0.8dl/g)andPTT(Intrinsicviscosity1.0dl/g)wereprovidedbyDuPontandusedwithoutfurtherpurification.
Methods:
1.SEManalysis:ThemorphologicalstructureofPET/PTTblendswasobservedusingascanningelectronmicroscope.
2.DSCanalysis:ThemeltingtemperatureandmeltingenthalpyofPET/PTTblendsweredeterminedbydifferentialscanningcalorimetry.
3.Tensiletesting:ThetensilestrengthandelongationatbreakofPET/PTTblendsweremeasuredaccordingtoASTMstandardD638-17.
4.Environmentalstresscracking:TheenvironmentalstresscrackingresistanceofPET/PTTblendswastestedaccordingtoASTMstandardD1693-15.
Resultsanddiscussion
SEManalysis:TheSEMimagesofPET/PTTblendswithdifferentratiosshowedthatthephasemorphologychangedfromacoarsephaseseparationtoafinedispersionwithincreasingPETcontent.WhenthePETcontentwas50%,theblendshowedauniformandcontinuousmorphology,indicatingthatacompatibilizedblendwasformed.
DSCanalysis:ThemeltingtemperatureandmeltingenthalpyoftheblendsincreasedwithanincreaseinPETcontent,thisshowedthattheblendbecamemorethermallystablewiththeadditionofPET.
Tensi