聚对苯二甲酸乙二酯/蒙脱土纳米复合材料的制备和性能

讨论了聚对苯二甲酸乙二醇酯（ＰＥＴ）／层状硅酸盐（蒙脱土）纳米复合材料的制备技术和新材料的结构与性能特征．天然蒙脱土矿物经有机离子修饰剂处理后，参与ＰＥＴ的缩聚反应．ＴＥＭ测定证实蒙脱土在ＰＥＴ中的层厚分布为３０～５０ｎｍ．蒙脱土不影响ＰＥＴ的分子量及其分布．利用ＤＳＣ、ＷＡＸＤ、ＳＡＬＳ和偏光显微镜测定了ＰＥＴ／蒙脱土的结晶速率和结晶形态，说明ＰＥＴ／蒙脱土有着很快的结晶速率，不能生成球晶结构，一般只能生成结构不完整的微晶体．ＰＥＴ／蒙脱土在工程塑料和工业纤维领域有潜在的应用前景

SYNTHESIS AND PROPERTIES OF PET-CLAY NANO-COMPOSITE

PET\|clay hybrid is a nano composite of PET and uniformly dispersed silicate layers of montmorillonite.Cation exchange capacity of the montmorillonite used in our laboratory is 90 meq./100g.The montmorillonite is a sheet\|like particles which are composed of monolayer of 10nm long,10nm wide and 1nm thick.Montmorillonite was dispersed in water or EG,then a kind of nitrogen\|onium ion was added to exchange cations between layers of the montmorillonite.Because interlayers were intercalated by onium ion,the interlayer spaces were increased,subsequently the layers of the montmorillonite were delaminated and uniformly dispersed in the solvent.The above treated montmorillonite was mixed with PET oligomer.The mixtures were reacted for 34 h at 260 to 280,then the PET\|clay hybrids were yielded.It is revealed by electron microscopy that the montmorillonite layers are uniformly dispersed at 3050 nm layer thick in the PET matrix. Crystallization rate of PET\|clay is about 45 times as quick as that of PET. X\|ray patterns of PET\|clay hybrids which was quenched at 160/min were obtained by WAXD.Crystallinities were calculated by peak resolution method.It is about 53% for quenched PET\|clay and much higher than that of pure PET.Neither quenching nor isothermal samples show perfect spherulite structure.It is too small for the size of the spherulite to observe as typical pattern of PET spherulite using polar microscopy and SALS. The montmorillonite layers could act as nucleating agents during crystallization thus increasing crystallization rate, so that molding temperature could be decreased to 6080 during the injection molding. Mechanical and thermal properties of the hybrids were superior to those of PET.The PET\|clay hybrids have excellent spinnability. The tensile modulus of the fibers spun by the hybrids is 160% as high as the one of PET fibers.\=