硅氧烯负载Ziegler-Natta催化剂的制备及其催化乙烯聚合的研究

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关键词：硅氧烯；接枝改性;Ziegler-Natta催化剂；烯烃；原位聚合；聚乙烯;纳米复合材料 中图分类号：TQ325.1 文献标志码：A doi：10.12415/j.issn.1671-7872.25087

Abstract： In this studya siloxene-supported Ziegler-Natta catalyst was developed，and polyethylene/siloxene nanocomposites were successully prepared via in-situ polymerization.Two-dimensional siloxene material was first synthesized by an etching method，and its surface was graft-modified with octadecylamine.The polar groups on the modified siloxene were then utilized to support the Ziegler-Natta catalyst.After activation with triethylaluminum， ethylene in-situ polymerization was caried out.The influence ofsiloxene on the catalyst properties，the role of the supported catalyst in ethylene polymerizationactivity，and the variations in the properties of the resultingcomposites weresystematically investigated.The results demonstrate that the prepared siloxene-supported ZieglerNatacatalyst exhibits significantly higher activity than the conventional Zigler-Natta catalyst.After polymerization， the siloxene isuniformly dispersed in the polyethylene matrix，efectively enhancing the mechanical and thermal properties of the matrix. With only 0.62% （mass fraction） siloxene addition， the tensile strength， elastic modulus， and elongation atbreakof thecomposite are increased by 129.5% 54.1% ，and 58.0% ，respectively，comparedwith those of pure polyethylene， while the thermal decomposition temperature （ （θd5%） is raised by 54.3‰ . This study provides a novel and efective strategy for preparing high-performance polyolefin nanocomposites.By overcoming the limitations ofconventionalmaterials inmechanical strengthandthermal stabilityitalsoestablishesafoundationfor expanding their applications in critical fields such as high-end packaging， new energy，and precision manufacturing.

Keywords：siloxene;graft modification；Ziegler-Natta catalyst；olefin；in-situ polymerization;polyethylene; nanocomposite

聚烯烃作为全球产量最高的合成聚合物之一，其产量约占塑料总量的 50% ，是日常生活中应用最广泛的化工材料[。（剩余18042字）