国内LLDPE市场浅析

在综述了美国、加拿大、西欧、日本LLDPE树脂市场消费状况和发展趋势的基础上,重点分析了美国、西欧薄膜料LLDPE树脂的应用市场和消费走向,并提出了适合我国市场情况的LLDPE品种生产的比例及我国LLDPE树脂研究开发的建议。     

聚乙烯树脂

LL4004EL是一种线性低密度聚乙烯（LLDPE）树脂，用于低压供电电缆绝缘。据说，该树脂可达到交联速度与易于加工性能之间的良好平衡，价格有竞争力。由于优化了防老剂，改善了聚合物的性能，该树脂特别适用预硅烷交联工艺，因为对该工艺来说，交联速度和加工性是关键因素。LL4004EL树脂已经过两年的现场实验，适于在一步和两步加工工艺中使用。     

LLDPE树脂专用复合抗氧剂的研究

针对LLDPE树脂分子特征,选用国产单一抗氧剂进行复合研究,从中优选出性能优良的复合抗氧剂(代号CAO-Ⅲ),并对使用该抗氧剂的树脂进行了物理性能测试、抗热加工老化性能试验以及使用性能试验,同时与进口助剂进行了对比试验。     

茂金属聚乙烯(MPE)/线性低密度聚乙烯(LLDPE)共混熔体的流变学

研究了不同比例共混的茂金属聚乙烯 (MPE)和线性低密度聚乙烯 (LLDPE)熔体的流变学行为 ,讨论了共混物组成、剪切速率和剪切应力以及温度对熔体流变曲线、熔体粘度的影响 ,为MPE的共混改性提供了理论依据。结果表明 :随着LLDPE含量的增加 ,共混熔体的粘度降低 ,转变应力和非牛顿指数减小 ,粘流活化能升高 ,MPE的流动性和加工性能得到改善。     

茂金属聚乙烯（MPE）／线性低密度聚乙烯（LLDPE）共混溶体的流变学

研究了不同比例共混的茂金属聚乙烯（MPE）和线性低密度聚乙烯（LLDPE）熔体的流变学,讨论了共混物组成、剪切速率和剪切应力以及温度对熔体流变曲线、熔体粘度的影响,为MPE的共混改性提供了理论依据。结果表明：随着LLDPE含量的增加,共混熔体的粘度降低,转变应力和非牛顿指数减小,粘流活化能升高,MPE的流动性和加工性能得到改善。     

高性能LLDPE电缆护套的研制

采用扬子石化公司生产的LLDPEX基体树脂制备通信电缆用黑色LLDPE电缆护套料,研究了电缆护套料各组分选择、用量和加工工艺对其性能的影响,给出了成型电缆护套的工艺条件。结果表明,该电缆护套料的配方合理、加工工艺可行,性能达到了国家标准要求,尤其是拉伸强度、断裂伸长率、耐环境应力开裂等性能优异。该电缆护套料的加工性能可满足生产通信电缆外层护套的要求,生产的护套的各项指标均达到邮电部标准要求。     

高密度聚乙烯和线性低密度聚乙烯共混用于包装薄膜的生产

研讨了线性低密度聚乙烯(LLDPE)/高密度聚乙烯(HDPE)共混取代线性低密度聚乙烯(LLDPE)/低密度聚乙烯(LDPE)共混用于包装薄膜的生产,并测试了其物理性能。     

模压法制备LLDPE高发泡塑料的研究

研究了用模压法制备线型低密度聚乙烯(LLDPE)的高发泡泡沫塑料。探讨了发泡剂、交联剂、促进剂以及LLDPE与低密度聚乙烯(LDPE)的配比对高发泡塑料的表观密度、回弹率、压缩永久变形和压缩强度的影响。实验结果表明,在合适的配方和工艺条件下,以LLDPE为主,配以少量的LDPE树脂可制得高发泡塑料。     

埃克森美孚推出新型包装用HDPE树脂——HTA108

美国埃克森美孚化学公司近日推出一种用于共挤压或与聚乙烯掺混的新型高密度聚乙烯(HDPE)树脂产品——HTA108，该产品具有优良的强度、韧性和阻隔性能。当它与线性低密度聚乙烯(LLDPE)或茂金属线性低密度聚乙烯(mLLDPE)掺混时，这种新型HTA108HDPE可以提高聚乙烯的加工成型性能。     

线性聚乙烯的主要生产技术及进展

PROCESSTECHNOLOGYANDPROGESSPOLYETHYLENE1前言线性聚乙烯（LLDPE）从70年代末实现工业化生产以来,迅速变成聚乙烯产品中的第三大品种。全球生产LLDPE主要采用的工艺有气相工艺、溶液工艺、浆液工艺。国际上各大公司为了提高竞争能力,保持竞争中的优势,除了开发极低密度（VLDPE）、超低密度聚乙烯（ULDP）、“双峰”树脂、宽分子量分布树脂新的产品外,还加大力度对催化剂技术、工艺技术和MXIPE的功能化进行专门开发和研究。象茂金属催化剂、冷凝态循环撤热技术、超临界浆液法技术和球形粒子树脂技术都是各大…     

线型低密度聚乙烯的改性研究进展

综述了近几年线型低密度聚乙烯(LLDPE)的改性在力学、阻燃、电学、结晶等性能上取得的研究进展,并对未来LLDPE改性的研究方向进行了展望。     

反应挤出制备的接枝LLDPE流变性

采用恒速型双毛细管流变仪定量研究了线型低密度聚乙烯(LLDPE)及其反应挤出接枝料的流变行为,研究了接枝改性对反应接枝料熔体的粘弹性、挤出压力振荡及挤出物外观影响。结果表明,反应接枝使LLDPE的平均相对分子质量增加,粘流活化能增大。高速挤出时,LLDPE的挤出压力出现振荡现象,挤出物表观出现鲨鱼皮畸变;相对而言,反应接枝料的挤出过程更加稳定,挤出物表观得到改善。     

国外LLDPE树脂现状及发展预测

对近10年来国外部分地区和国家的线性低密度聚乙烯(LLDPE)的生产能力、产量、消费量、产品用途分配、进出口及价格情况进行了详细的综述和分析,同时对国外LLDPE的发展趋势作了预测。     

开口剂在LLDPE中的应用

通过无机、有机、复配开口剂对线型低密度聚乙烯(LLDPE)爽滑、开口性能的改进研究发现,添加复配开口剂可使LLDPE薄膜获得理想的爽滑、开口性能,并在LLDPE装置上成功实现工业化生产,且生产平稳可控.工业化产品测试结果表明:LLDPE产品PE-l的熔体流动速率为2.0 g/10 min,拉伸屈服应力为10.20 MPa;薄膜雾度为28.1%,动摩擦系数为0.342,静摩擦系数为0.307,薄膜爽滑、开口性能得到大幅改进,满足质量指标要求.     

LLDPE/LDPE blends. I. Rheological,thermal, and mechanical properties

Structure and mechanical properties were studied for the binary blends of a linear low density polyethylene (LLDPE) (ethylene‐1‐hexene copolymer; density = 900 kg m⁻³) with narrow short chain branching distribution and a low density polyethylene (LDPE) which is characterized by the long chain branches. It was found by the rheological measurements that the LLDPE and the LDPE are miscible in the molten state. The steady‐state rheological properties of the blends can be predicted using oscillatory shear moduli. Furthermore, the crystallization temperature of LDPE is higher than that of the LLDPE and is found to act as a nucleating agent for the crystallization of the LLDPE. Consequently, the melting temperature, degree of crystallinity, and hardness of the blend increase rapidly with increases in the LDPE content in the blend, even though the amount of the LDPE in the blend is small. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3153–3159, 1999     

双峰型LE6592 LLDPE的性能研究

分析了部分第一代聚乙烯和第二代聚乙烯双峰型膜料ＬＥ６５９２ ＬＬＤＰＥ的结晶和流变行为，对比了它们的成膜情况及薄膜性能，总结了ＬＥ６５９２ ＬＬＤＰＥ膜的力学性能随膜厚度、膜泡瓶颈高度及吹胀比变化的规律。     

Thermostimulative shape memory effect of linear low‐density polyethylene/polypropylene (LLDPE/PP) blends compatibilized by crosslinked LLDPE/PP blend (LLDPE–PP)

A novel linear low‐density polyethylene (LLDPE)/polypropylene (PP) thermostimulative shape memory blends were prepared by melt blending with moderate crosslinked LLDPE/PP blend (LLDPE–PP) as compatibilizer. In this shape memory polymer (SMP) blends, dispersed PP acted as fixed phase whereas continuous LLDPE phase acted as reversible or switch phase. LLDPE–PP improved the compatibility of LLDPE/PP blends as shown in scanning electron microscopic photos. Dynamic mechanical analysis test showed that the melt strengths of the blends were enhanced with increasing LLDPE–PP content. A shape memory mechanism for this type of SMP system was then concluded. It was found that when the blend ratio of LLDPE/PP/LLDPE–PP was 87/13/6, the blend exhibited the best shape memory effect at stretch ratio of 80%, stretch rate of 25 mm/min, and recovery temperature of 135°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Thermoplastic Elastomers Derived from Scrap Rubber Powder/LLDPE Blend with LLDPE‐graft‐(Epoxidized Natural Rubber) Dual Compatibilizer

Summary: Attempts were made to prepare thermoplastic elastomers (TPE) from scrap rubber powder (SRP) and linear low‐density polyethylene (LLDPE) as thermoplastic polymer matrix. The solid‐phase grafted copolymer of LLDPE (LLDPE‐g‐VM) and epoxidized natural rubber (ENR) were used as dual compatibilizers to improve the interfacial adhesion between SRP and LLDPE. The compatibilized SRP/LLDPE blends had obviously improved the interfacial properties between SRP particles and LLDPE. Using this method, thermoplastic elastomer was prepared successfully. The mechanical properties especially elongation at break was improved significantly. SEM and TEM studies showed that the ENR/LLDPE‐g‐VM dual compatibilizer improved the distribution state of SRP particles in LLDPE and the adhesion between SRP and LLDPE. DSC results showed a distinct glass transition at 74 °C of the interfacial region. The improvement in mechanical properties was attributed to the enhanced interfacial properties of the blend.

Surface of SRP particles of the composites compatibilized by the dual compatibilizer.     

Thermal properties and morphology of recycled poly(ethylene terephthalate)/maleic anhydride grafted linear low‐density polyethylene blends

Properties of recycled Poly(ethylene terephthalate) were greatly improved. Recycled PET was blended with LLDPE‐g‐MA by low‐temperature solid‐state extrusion. Mechanical properties of the blends were affected obviously by the added LLDPE‐g‐MA. Elongation at break reaches 352.8% when the blend contains 10 wt % LLDPE‐g‐MA. Crystallization behavior of PET phase was affected by LLDPE‐g‐MA content. Crystallinity of PET decreased with the increase of LLDPE‐g‐MA content. FTIR testified that maleic anhydride group in LLDPE‐g‐MA reacted with the end hydroxyl groups of PET and PET‐co‐LLDPE‐g‐MA copolymers were in situ synthesized. SEM micrographs display that LLDPE‐g‐MA phase and PET phase are incompatible and the compatibility of the blends can be improved by the forming of PET‐co‐LLDPE‐g‐MA copolymer. LLDPE‐g‐MA content was less, the LLDPE‐g‐MA phase dispersed in PET matrix fine. With the increase of LLDPE‐g‐MA content, the morphology of dispersed LLDPE‐g‐MA phase changed from spherule to cigar bar, then to irregular spherule. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008