化学交联聚乙烯热收缩管的研制

研究化学交联聚乙烯热收缩材料的凝胶含量、拉伸强度及断裂伸长率的变化规律，同时对其电性能和管材的扩张和热收缩性能也作了初步探讨。结果表明，随着乙烯基三乙氧基硅烷（A-151）用量的增加，材料的凝胶含量、拉伸强度均有不同程度地增加，而断裂伸长率却下降；（乙烯／乙酸乙烯酯）共聚物能提高材料的断裂伸长率。但对拉伸强度的影响不大；管材扩张后能恢复原位，其热收缩温度为105～130℃，纵向收缩率为5．9％，满足使用要求，     

聚乙烯泡沫塑料的研制

将线型低密度聚乙烯和低密度聚乙烯结合后，选用化学交联法生产闭孔软质泡沫塑料。     

化学交联聚乙烯泡沫在汽车领域的应用

介绍了化学交联聚乙烯泡沫在汽车领域的应用,主要用途包括汽车内顶饰,行李箱、地垫、侧围板、隔热垫、门内护板、防水帘、遮阳板、打蜡盘、空调系统等。分别介绍了其特点、结构、工艺及使用情况。     

化学交联聚乙烯热收缩管成型

本文讨论化学交联聚乙烯热收缩管成型加工实验结果。     

超高分子量聚乙烯微孔材料微观结构形态学表征

超高分子量聚乙烯（ＵＨＭＷ－ＰＥ）具有优异的综合性能,以ＵＨＭＷ－ＰＥ为基体的微孔材料在医药,环保,能源等领域具有非常广泛的应用前景。利用压汞法对不同ＵＨＭＷ－ＰＥ微孔材料的微观结构参数进行测定和比较,通过孔积分布函数、分形维数等方面的研究对ＵＨＭＷ－ＰＥ微孔材料的微观结构形态及其分布进行了初步的量化表征,并分析了不同参数所代表的物理意义。     

超高分子量聚乙烯微孔材料微观结构形成机理的研究

超高分子量聚乙烯（ＵＨＭＷ－ＰＥ）微孔材料是以ＵＨＭＷ－ＰＥ为聚合物基体的一种新型功能性材料,利用这种材料能够晨均相分离、过主离子通透等多种单元操作过程,可广泛地应用于化工、医药、能源等领域。针对ＵＨＭＷ－ＰＥ物料的特殊性能,采用热致相分离方法（ＴＩＰＳ）进行微孔 成型。ＴＩＰＳ过程涉及到聚合物－溶剂二元体系,因此对ＴＩＰＳ的二元体系热力学过程进行了研究。同时,二元体系的相健康对微观结构有很大的影     

超高摩尔质量聚乙烯微孔材料亲水性能的改善

通过改善结构、添加表面活性剂以及浸泡三种方法对采用热致相分离法制成的超高摩尔质量聚乙烯微孔材料的亲水性能进行了改善，效果均很明显。并通过对其它综合性能进行的比较发现，这几种方法并未影响到材料的其它使用性能。     

化学交联聚乙烯管定径过程的计算模型分析

介绍化学交联聚乙烯管定径过程的计算模型分析。对于管坯区域,假设导热系数α及热容ＣＰ为常数;忽略Ｘ方向和ｙ＝０处的热传导,得到通过定径套带走的热量λ∫ｌｏ（Ｔｗ－Ｔｓ）δ２ｄｓ＞ＣＰρπ（Ｒ２－ｒ２）（Ｔｍ－Ｔｇ）υｘ从而可得到冷却水温Ｔｓ、管坯温度Ｔｍ、牵引速度νｘ、管壁厚度δ１及定径套厚度δ２等参数之间的关系。对于给定的管材规格,绘出了牵引速度和冷却水温选择图,由该图得出最大生产能力区。     

聚对苯二甲酸乙二醇酯的改性及其发泡材料的最新进展

综述了聚对苯二甲酸乙二醇酯(PET)的改性方法及其发泡工艺的研究进展,其中改性方法主要包括固相缩聚、原位共聚和扩链改性,发泡工艺主要有釜压法、模压法、挤出法等.最后,简要介绍了我国PET发泡材料的工业化现状,并指出未来研究和发展的方向.     

国内聚乙烯接枝和交联改性的研究进展

综述了国内聚乙烯接枝改性和交联改性技术的最新进展。     

微发泡弹性体材料的研究进展

微发泡弹性体材料是一种重要的高分子材料，它有其独特的微孔结构能够满足多方面的需要，因此也成为近来一段时间研究的热点。本文综述了其微孔成型机理及其制备微发泡弹性体材料的几个重要的方面即发泡剂的选择、发泡助剂的选择及交联过程和发泡过程的匹配，通过恰当的控制这几个方面，可以制得性能良好的微发泡弹性体材料。     

Study on the foaming of crosslinked polyethylene

The processing of crosslinked polyethylene foam, which has a closed‐cell structure, has been investigated. In this study, two types of linear low‐density polyethylene (LL) produced by a metallocene catalyst were crosslinked by dicumyl peroxide (DCP). The expansion ratio of the foams decreases with increasing the DCP content, which is due to the enhancement of the elastic modulus. Moreover, the crystallization temperature T_c of the foams is also responsible for the expansion ratio. After expansion, the crosslinked foam with lower T_c shrinks to a great degree prior to the crystallization, which is attributed to the volume reduction of the gas in the cells. As a result, the expansion ratio decreases. The degree of shrinkage decreases with increasing the T_c, because immediate crystallization prevents the shrinkage. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2146–2155, 2001     

ABS微孔发泡材料的制备与性能研究

利用化学交联模压法制备了丙烯腈–丁二烯–苯乙烯塑料(ABS)微孔发泡材料,研究了发泡剂偶氮二甲酰胺(AC)、活化剂氧化锌(ZnO)、交联剂过氧化二异丙苯(DCP)用量对ABS微孔发泡材料力学性能和泡孔结构形态的影响。结果表明,当AC为2份、DCP为0.15份、ZnO为0.2份时,制得的ABS微孔发泡材料的泡孔密度为1.31×108cells/cm3,平均泡孔尺寸为24μm,比强度达到44.7 N/tex,综合性能最佳,可以满足微孔发泡材料的要求。     

发泡PET研究进展

介绍了聚对苯二甲酸乙二醇酯(PET)提高熔体强度的方法,主要有固相缩聚、长链支化等,讨论了各种方法的国内外研究情况,以及国内外在发泡理论、应用方面的最新进展,对PET发泡前景进行了展望。     

聚乙二醇/二氧化硅定形相变材料的制备

采用多孔二氧化硅（SiO₂）、聚乙二醇(PEG)等研究一种定形无机 有机复合相变材料的制备方法,并加入适当的促进剂和改性剂对复合材料进行了改性。利用多孔二氧化硅具有良好的吸附性能特点,将聚乙二醇相变材料吸附在二氧化硅微孔结构内,在毛细管力和表面张力的作用下,聚乙二醇在发生固液相变的时候很难从二氧化硅的微孔结构内渗透出来,从而解决了聚乙二醇在蓄热技术中应用时的液体流动问题。同时对相变材料进行了热性能分析,实验证明该复合相变材料具有形状稳定,导热率高,储热能力大等特点。     

Lightweight polyethylene terephthalate bead foams with good interfacial adhesion and thermal insulation performance fabricated by supercritical carbon dioxide secondary foaming strategy

This paper reported the novel supercritical carbon dioxide (scCO₂) secondary foaming and molding strategy to prepare the thermal-insulation polyethylene terephthalate (PET) bead foam part with good interfacial adhesion and high expansion ratio. The incorporation of porous structure could effectively enhance the blowing agent solubility and fabricate the system viscosity difference, which contributed to the expansion and further welding of the expanded PET beads. Under the optimum foaming conditions, PET bead foam parts with excellent comprehensive performance were successfully prepared by molding method in the confined space via scCO₂ secondary foaming, and the corresponding welding mechanism of PET beads was further investigated. The obtained foam parts possessed good tensile and compressive properties, reaching 1.03 and 1.27 MPa (at 20% strain) respectively. Besides, the foam part exhibited the low thermal conductivity of 0.060 Wm⁻¹ K⁻¹, which confirmed the improvement of thermal insulation performance owing to the high expansion ratio.     

Microcellular foaming of PE/PP blends

Three different polyethylene/polypropylene (PE/PP) blends were microcellular foamed and their crystallinities and melt strengths were investigated. The relationship between crystallinity, melt strength, and cellular structure was studied. Experimental results showed that the three blends had similar variation patterns in respect of crystallinity, melt strength, and cellular structure, and these variation patterns were correlative for each blend. For all blends, the melt strength and PP melting point initially heightened and then lowered, the PP crystallinity first decreased, and then increased as the PE content increased. At PE content of 30%, the melt strength and PP melting point were highest and the PP crystallinity was least. The blend with lower PP crystallinity and higher melt strength had better cellular structure and broader microcellular foaming temperature range. So, three blends had best cellular structure at PE content of 30%. Furthermore, when compared with PE/homopolymer (hPP) blend, the PE/copolymer PP (cPP) blend had higher melt strength, better cellular structure, and wider microcellular foaming temperature range, so it was more suited to be microcellular foamed. Whereas LDPE/cPP blend had the broadest microcellular foaming temperature range because of its highest melt strength within three blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4149–4159, 2007