可控流变PP的制备

以抗冲共聚聚丙烯(PP)作为基础树脂,采用可控流变技术制备了不同流动性能的可控流变聚丙烯(CRPP).研究了CRPP与基础树脂性能之间的关系以及CRPP的链结构、结晶行为、相态结构和流变行为.结果表明:高流动CRPP的性能与基础树脂的性能关系密切:可控流变技术难以获得高拉伸断裂应变和高冲击强度的高流动CRPP;降解剂用量为700μg时,CRPP的重均分子量从2.270×10s降至1.351×104,相对分子质量分布从6.49降至4.71;高流动CRPP的相态结构与基础树脂明显不同.     

四川石化聚丙烯装置开发抗冲共聚新品

<正>四川石化45万吨/年聚丙烯装置二号反应器在线转产CI36D高端抗冲共聚聚丙烯产品近日获得成功。这是继二号反应器成功生产出优级C128F高端抗冲共聚聚丙烯产品后,该公司开发的另一高端抗冲共聚产品。CI28F、CI36D具有熔体流动速率稳定、气味低、白度高的特性,同时保持了高抗冲共聚聚丙烯高橡胶含     

HR催化剂制备高性能聚丙烯的研究

分别采用HR催化剂和进口催化剂在25 kg/h的环管中试装置上,制备了高光泽抗冲共聚聚丙烯与透明抗冲共聚聚丙烯,研究了产品的结构与性能.结果表明:HR催化剂的氢调敏感性更好,制备相同熔体流动速率高光泽抗冲共聚聚丙烯和透明抗冲共聚聚丙烯时加入的氢气量更少,提升了生产负荷,均聚聚丙烯等规指数更高,最终产品的相对分子质量分布...     

大庆炼化抗冲PP实现规模化生产

近日，从大庆炼化公司获悉，该公司最近实现EPT30R、EPC30R、SP179三个抗冲共聚聚丙烯牌号的成功切换。目前，该公司抗冲共聚聚丙烯年产能力已经达到30万t，在国内率先实现了此类产品的大批量规模化生产。抗冲共聚聚丙烯是一种市场前景看好、技术含量高、附加值高的产品，此前国内装置最多只能达到15万t／a的生产能力。大庆炼化聚丙烯装置设计产能为30万如。按照设计，该装置可生产103种牌号的聚丙烯。     

大庆炼化抗冲PP实现规模化生产

大庆炼化公司最近实现E P T30R、EPC30R、SP179三个抗冲共聚聚丙烯牌号的成功切换。目前,该公司抗冲共聚聚丙烯年产能力已经达到30万吨,在国内率先实现了此类产品的大批量规模化生产。抗冲共聚聚丙烯是一种市场前景看好、技术含量高、附加值高的产品,此前国内装置最多只能达到1     

高流动性抗冲共聚聚丙烯树脂的开发

采用流变改性工艺生产高流动性抗冲共聚聚丙烯树脂,通过研究母料添加量、乙烯含量、加工温度等因素对树脂性能的影响,实现对流变改性工艺的有效控制,获得流动性和抗冲击性能优异的高流动性抗冲共聚聚丙烯。     

抗冲共聚聚丙烯在Novolen装置上的生产

对Novolen工艺中抗冲共聚聚丙烯生产的共聚反应机理、产品质量控制原理、工艺调节措施进行了综述。影响抗冲共聚物产品质量的主要因素有均聚物MFR、粉料总MFR、乙烯总含量和橡胶相中乙烯含量。只有对每个影响因素进行仔细选择和控制才能得到高质量的抗冲共聚聚丙烯产品。此外,以抗冲共聚聚丙烯2500H生产为例,对抗冲共聚聚丙烯产品的生产过渡步骤进行了研究,并对得到的产品进行了分析讨论。     

Unipol气相法聚丙烯装置IRTS堵塞问题的研究与分析

Unipol气相流化床工艺聚丙烯装置有两台反应器,第一反应系统单独运行,用于生产均聚产品和无规共聚产品;第一反应系统和第二反应系统串联运行,用于生产抗冲共聚产品。在生产抗冲共聚产品时,装置中间传输系统(IRTS)下料线经常出现周期性堵塞,导致第二反应系统无法长周期运行。结合理论研究与生产实际数据,通过分析IRTS管线吹扫气流量、产品橡胶含量、不同的助催化剂(给电子体)、第二反应器床层重量和床层高度控制等因素,探求造成中间传输系统下料线堵塞的根本原因,并通过工艺调整解决该问题,从而促进装置第二反应系统的长周期运行,抗冲共聚产品的长周期生产,为同类装置提供数据支持和理论依据。     

可控流变抗冲共聚聚丙烯的相分离及增长模型

研究了抗冲共聚聚丙烯(ICPP)和可控流变抗冲共聚聚丙烯(CRICPP)的流变行为以及亚微观形态.结果表明:CRICPP在加工流动性大幅度提高的同时,经注塑加工,相分离后的形态与ICPP明显不同; ICPP的分散相由较大的颗粒组成;而CRICPP则由多个小颗粒聚集而成,且随着过氧化物含量的提高,组成分散相的颗粒尺寸明显变小.为直观描述ICPP及CRICPP的相分离过程,建立了相应的分散相增长模型.     

提高聚丙烯抗冲共聚物低温冲击强度的研究

本文介绍聚丙烯抗冲共聚物的生产工艺和产品的结构性能,针对低温冲击强度对聚丙烯抗冲共聚物的重要性做了阐述,同时结合抗冲聚丙烯EPS30R从工艺控制的角度出发,着重从生产过程中的乙烯用量、氢气用量、催化剂选型、橡胶含量、MFR、凝胶体含量、和停留时间几个方面进行了认真的分析,得出了提高产品低温冲击强度的有效途径。总结抗冲共聚聚丙烯结构研究方法及发展方向,以利于抗冲共聚聚丙烯新产品的进一步开发。展望了抗冲共聚聚丙烯领域的某些可能发展。     

无规共聚聚丙烯的结构与性能

利用博里叶变换红外光谱仪与差示扫描量热仪分析了五种无规共聚聚丙烯(PP)的组成和结构,测试了五种PP产品的力学与光学性能.五种无规共聚PP都是由乙烯与丙烯无规共聚合而成,在高分子链中没有乙烯结晶.PP树脂的拉伸屈服应力随着共聚单体乙烯含量的升高而降低,Izod缺口冲击强度、光学性能随着乙烯含量的增加而提高.加入乙烯的质量分数控制在2％～3％为宜.     

Spheripol工艺生产高抗冲聚丙烯

介绍了Spheripol工艺生产高抗冲聚丙烯产品的方法,采用两步复合工艺生产嵌段聚丙烯,第1步采用环管反应器进行丙烯液相均聚反应,第2步采用流化床反应器进行丙烯均聚物与乙烯单体气相共聚反应,即在气相反应器中,利用来自环管反应器中的均聚物的残余活性,加入乙烯和补充的丙烯及氢气实现乙-丙共聚,共聚物的生成使最终产品的抗冲性能大大提高,尤其是低温下的抗冲性能。     

Influences of copolymerization conditions on the structure and properties of isotactic polypropylene/ethylene–propylene random copolymer in situ blends

A spherical TiCl₄/MgCl₂‐based catalyst was used in the synthesis of in situ isotactic polypropylene/ethylene–propylene random copolymer blends by propylene bulk polymerization and subsequent gas‐phase copolymerization of ethylene with propylene. Different copolymerization conditions, such as the reaction time, monomer pressure, and composition, were investigated, and their influences on the structure and properties of the products were studied. Raising the monomer pressure was the most effective way of speeding up the copolymerization, but it caused more increases in the random copolymer than the block copolymer fractions. Increasing the ethylene content of the monomer feed also resulted in higher reaction rates and copolymer contents, but the ethylene contents of both the random and block copolymer fractions were also raised. In situ blends that contain more than 50 wt % copolymer were prepared. The mechanical properties of the blends, including the impact strength and flexural modulus, were regulated in a rather broad range with changes in the copolymerization conditions. The properties were highly dependent on the amount, distribution, and chain structure of the copolymer fractions. The impact strength was influenced by both the random copolymer and block copolymer portions in a complicated way, whereas the flexural modulus was mainly determined by the amount of random copolymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 445–453, 2002; DOI 10.1002/app.10415     

Study on morphology of high impact polypropylene prepared by in situ blending

High impact polypropylene (HIPP) was prepared by in situ blending of isotactic polypropylene and ethylene–propylene rubber (EPR) with spherical Ziegler–Natta catalyst. Morphology and pore characteristics of such HIPP were investigated by scanning electron microscope, atomic force microscopy, and mercury intrusion. Amorphous phase was removed from polypropylene matrix and characterized by ¹³C NMR spectrum. It was found that the EPR prepared in this manner contained variable composition polymer chains with a distribution of ethylene and propylene sequence lengths. Final products of HIPP were free flowing, spherical granules. There were small pores in HIPP, which seemed not to be filled up, and could be determined by mercury intrusion even when the content of rubber was up to 24 wt %. Homopolypropylene with pore diameter between 100 and 10,000 nm was suitable for EPR to fill in during ethylene–propylene copolymerization. The block copolymer fractions act as a compatilizer between matrix and EPR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1386–1390, 2006     

Morphology and mechanical properties of polypropylene/polyamide 6 nanocomposites prepared by a two‐step melt‐compounding process

Polypropylene/polyamide 6 blends and their nanocomposites with layered silicates or talc were prepared in a melt‐compounding process to explore their mechanical performance. The thermomechanical behavior, crystallization effects, rheology, and morphology of these materials were studied with a wide range of experimental techniques. In all cases, the inorganic filler was enriched in the polyamide phase and resulted in a phase coarsening of the polypropylene/polyamide nanocomposite in comparison with the nonfilled polypropylene/polyamide blend. The mechanical properties of these nanoblends were consequently only slightly better than those of the pure polymers with respect to the modulus, whereas the impact level was below that of the pure polymers, reflecting the heterogeneity of the nanoblend. Polymer‐specific organic modification of the nanoclays did not result in a better phase distribution, which would be required for better overall performance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 283–291, 2006     

聚丙烯的改性

介绍了目前广泛采用的聚丙烯改性研究方法,包括共聚,接枝,交联,填充,增强及共混改性,并重点讨论了纳米粒子改性PP的新技术,结果认为纳米PP复合材料具有更好的刚性,保持了良好的低温冲击性。     

The role of crystallization kinetics in the development of the structure and properties of polypropylene filaments

The processing, structure, and properties of filaments melt spun from three polypropylenes with similar rheology but substantially different crystallization kinetics were studied. The crystallization kinetics of the homopolymer was increased by the addition of a nucleating agent, whereas slower crystallization kinetics was obtained through a small amount of random copolymerization with ethylene. The relative crystallization kinetics of these three polymers was examined under quiescent conditions using differential scanning calorimetry. The technique of on-line diameter and birefringence measurement was used to show the characteristics of the on-line crystallization of the different resins. It was found that changing the quiescent crystallization kinetics by either the addition of a nucleating agent or through copolymerization with ethylene can produce profound effects on the structure and properties of polypropylene as-spun filaments when they are spun under relatively low stress and low takeup velocity conditions. Higher takeup velocities and spinline stresses reduce the effect of differences in quiescent crystallization due to the influence of on-line stress-induced (molecular orientation-enhanced) crystallization. © 1993 John Wiley & Sons, Inc.     

国内车用改性聚丙烯的研究现状及进展

主要综述了近年来国内在车用改性聚丙烯材料方面的研究进展,重点介绍了高抗冲共聚聚丙烯、无机纤维和粒子增强聚丙烯、弹性体增韧聚丙烯以及低VOC聚丙烯和阻燃聚丙烯材料的制备方法和性能。     

Structured polymer blends: 2. Processing of polypropylene/EDPM blends: controlled rheology and morphology fixation via electron beam irradiation

Electron beam irradiation has been used to improve the processability of polypropylene/ethylene-propylenediene monomer (PP/EPDM) blends (controlled rheology) in combination with fixation of morphology by inducing crosslinks in the dispersed EPDM phase. An optimum morphology for impact toughening has been obtained via extrusion-blending high molecular weight PP with EPDM. Upon irradiation before subsequent processing (injection moulding) this morphology is fixated, whereas the viscosity of the blend decreases as a result of chain scission of the PP matrix. Impact strength and elongation at break of these irradiated blends are better than those of blends of low molecular weight PP with EPDM, which possess comparable overall viscosity.     

单体组成切换法调控聚丙烯/丁烯合金的结构与性能

为解决聚丙烯材料抗冲击强度低的问题,同时利用国内大量廉价的1-丁烯资源,采用单体组成切换法在反应器内进行丙烯本体均聚和丙烯/丁烯本体共聚,原位制备聚丙烯合金。该合金主要由丙丁无规共聚物、长丙烯链段的丙丁嵌段共聚物和高等规度的聚丙烯组成。共聚物作为橡胶相分散在聚丙烯基体中,形成海岛结构,充当应力集中点,起到诱发及终止银纹、吸收能量的作用。长丙烯链段的嵌段共聚物增加了橡胶相与基体的相容性,使合金材料具有优异的刚性和韧性平衡,材料的抗冲击强度最高达48.91 kJ/m²。本文探究了聚合工艺对合金组成结构的影响,并揭示了合金组成结构和相形态、力学性能的关系。