高极性聚丙烯的制备及其应用研究

利用双组分熔融接枝极性单体的方法,制备高极性聚丙烯材料。红外光谱和熔融指数表明,采用多组分熔融接枝体系,通过加入苯乙烯单体,能够有效地控制单组分熔融接枝聚丙烯体系中严重的聚丙烯降解反应,大幅度提高极性单体的接枝率,同时保持了聚丙烯优良的力学性能,从而获得一种力学性能优良的高极性聚丙烯材料。     

聚丙烯熔融接枝改性概述

本文综述了聚丙烯熔融接枝的接枝方法、原理、设备、产物表征以及接枝物的性能、微观结构及对聚丙烯共混体系的影响。     

聚丙烯熔融接枝改性概述

本文综述了聚丙烯熔融接枝的接枝方法、原理、设备、产物表以及接枝物的性能、微观结构及其对聚丙烯共混体系的影响。     

聚丙烯熔融接枝改性研究

采用熔融接枝的方法,研究了多组分体系下不同单体熔融接枝聚丙烯的性能。结果表明:在共单体苯乙烯、引发剂和聚丙烯相同的条件下,接枝物的极性均较未接枝的聚丙烯极性增加;不同单体所得接枝物的接枝率不同;熔体流动速率的降低使接枝物的加工性能有不同程度的下降。接枝物极性增加的趋势依次按接枝单体MAH、MMA、GMA递增。接枝物的偏光显微镜分析表明,接枝支链的生成可以促进聚丙烯的异相成核,使晶粒细化。     

聚丙烯固相接枝改性研究进展

聚丙烯(PP)接枝改性方法很多,主要有溶液法、熔融法、固相法等,其中固相接枝共聚法是一种高效节能的方法,笔者综述了聚丙烯固相接枝的研究进展。介绍了聚丙烯固相接枝反应受PP结构、等规度、粒径、空隙率等因素影响,同时从接枝单体、引发剂、界面剂和工艺等方面时PP固相接枝改性体系的影响因素进行了论述。     

马来酸酐接枝改性聚丙烯及其在木塑复合材料中的应用

通过双螺杆挤出机聚丙烯熔融挤出接枝马来酸酐制备马来酸酐接枝聚丙烯（PP-g-MAH）;研究了接枝单体马来酸酐（MAH）、引发剂DCP及共单体St等对聚丙烯（PP）熔融接枝MAH的接枝率的影响。将制备的接枝物应用于木塑复合材料中,发现木粉与聚丙烯之间的界面结合有了明显的改善,添加的PP-g-MAH增强了木粉和聚丙烯基体之间的黏合性,使两相结合得更紧密,进而提高了木塑复合材料的力学性能。     

高极性聚丙烯的制备及应用

利用双组分熔融接枝极性单体技术,制备高极性聚丙烯（ＰＰ）材料。红外光谱和熔体流动指数测试表明,采用双组分熔融接枝体系,通过加入苯乙烯单体,能够有效地控制单体分员接枝ＰＰ体系中严重的ＰＰ降解,大幅度提高极性单体的接枝率,同时保持了ＰＰ优良的力学性能,从而获得一种力学性能优良的高极性ＰＰ材料。     

新型聚丙烯接枝物的制备及应用

为制备强韧的共混材料,利用熔融接枝法研制了含有两种接技单体的新型聚丙烯接枝物,讨论了第二单体在接枝过程中的作用,并将其应用于尼龙6/聚丙烯(PA6/PP)共混体系,获得了使分散相粒径更细小、界面更模糊的增容效果。     

抗菌聚丙烯的制备及其抗菌性能

采用熔融接枝法将反应性有机抗菌剂接枝到聚丙烯上得到抗菌聚丙烯。通过控制有机抗菌剂的添加量,成功制备了一系列抗菌聚丙烯,研究了其对大肠杆菌和金黄色葡萄球菌的抗菌性能以及持久抗菌效果,并与采用共混法制备的抗菌聚丙烯进行比较。结果表明:采用熔融接枝法制备的抗菌聚丙烯的抑菌效率大于99%,所需最低抗菌剂含量为1%(w);通过反应性接枝引入抗菌基团的聚丙烯具有更持久的抗菌性能。     

聚丙烯熔融挤出接枝马来酸酐的研究

研究了通过双螺杆挤出机聚丙烯熔融挤出接枝马来酸酐制马来酸酐接枝聚丙烯（PP—g—MAH）的工艺，包括单体马来酸酐（MAH）、引发剂DCP的用量及熔融反应温度和时间对聚丙烯（PP）熔融接枝MAH的接枝率的影响。结果表明：DCP、MAH的用量对PP—g—MAH接枝率影响比较明显，其最佳配比为DCP0．15份、MAH2份；最佳工艺条件为挤出螺杆转速40r／min，反应温度195-200℃。     

多单体熔融接枝聚丙烯的研究进展

介绍了聚丙烯(PP)多单体熔融接枝聚合技术,总结了现阶段对多单体熔融接枝PP的研究现状,分别阐述了多单体熔融接枝PP的影响因素、性能及结构,以及多单体熔融接枝PP在尼龙中的应用;并指出了其存在的问题及发展前景.     

聚丙烯的绿色环保固相接枝法研究进展

随着国家对化工生产中的污染问题日益重视,传统的聚丙烯熔融接枝和溶液接枝的工业化生产面临巨大的考验,而发展绿色环保的聚丙烯固相接枝法成为研究的热点之一.从热引发、光引发、等离子体引发、辐射引发、其他方法等五个方面综述了绿色环保的聚丙烯固相接枝的研究进展,并分析了各种固相接枝法的优缺点,最后对绿色环保的聚丙烯固相接枝法的前...     

马来酸酐接枝聚丙烯研究进展

介绍了马来酸酐接枝聚丙烯的方法、机理,并重点介绍了溶液法和共单体熔融法影响接枝率的因素。     

马来酸酐接枝聚丙烯的方法及其发展

介绍了马来酸酐(MAH)接枝聚丙烯(PP)的方法,主要有熔融接枝、溶液接枝、固相接枝、悬浮接枝等。指出了每种接枝方法的优缺点及研究进展。提出了工业放大、接枝机理的研究以及接枝过程中应考虑经济环保等是接枝技术的发展方向。     

Microstructure and properties of polypropylene/glass fiber composites grafted with poly(pentaerythritol triacrylate)

Isotactic polypropylene(PP)/glass fiber(GF) composites were modified by grafting polymerization of polyfunctional monomer, pentaerythritol triacrylate (PETA), in the presence of 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane peroxide (DDHP) via melt extrusion. Fourier transform infrared spectroscopy (FTIR), melt strength test (MS), mechanical property test, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to characterize the microstructure and properties of the modified composites. The crystallization kinetics was investigated by Mo method while apparent activation energy of crystallization of the composites was determined by Kissinger method. The FTIR results showed that the acrylic polymers were grafted onto the polypropylene chains. The grafting made the melt strengths and the mechanical properties of the modified composites, and the interfacial adhesion between PP and glass fiber all enhanced. High melting and crystallization temperatures, high crystallization rate and large activation energy of crystallization were also obtained after grafting. In addition, the grafted acrylic polymers recovered the depressed crystallization of polypropylene and restrained α-β transition in fatigue experiment.     

Synergistic effect of styrene and zinc dimethyldithiocarbamate on the properties of high melt strength polypropylene

High melt strength polypropylene was successfully prepared by a reactive extrusion method, in which pure polypropylene without any additives was used as a basic resin; trimethylolpropane triacrylate was used as a grafting monomer, and styrene and zinc dimethyldithiocarbamate (ZDMC) were used as trapping radicals. The synergistic effects of styrene and ZDMC on melt strength and melt flow rate of modified polypropylene were investigated. When the additions of styrene and ZDMC were 3.5 parts by weight per hundred parts of resin (phr) and 0.3 phr, respectively, the melt strength of modified polypropylene (PP5) was about 21 cN, which was much higher than that of modified polypropylene without styrene (PP0, 4.6 cN). Moreover, crystallization behavior and mechanical properties of modified polypropylene were also investigated. The results showed that the melt and crystallization temperatures of modified polypropylene with styrene were higher than those without styrene, and the size of crystal was smaller. Moreover, the mechanical properties of modified polypropylene were greatly improved in the presence of styrene. J. VINYL ADDIT. TECHNOL., 24:13–17, 2018. © 2015 Society of Plastics Engineers     

聚烯烃接枝的研究进展

介绍了以过氧化物为中间产物的聚烯烃本体接枝、链转移反应、多单体熔融接枝的进展情况,重点阐述了表面接枝中的化学方法、利用辐照和光照技术对聚烯烃的表面改性、等离子体工艺及相关的聚丙烯表面改性剂。聚烯烃接枝是制备功能性聚烯烃的主要方法,也是高分子与工程材料领域最活跃的研究热点之一。     

Reactive extrusion of polypropylene with supercritical carbon dioxide: Free radical grafting of maleic anhydride

A reactive extrusion process for the functionalization of polypropylene with maleic anhydride in the presence of supercritical carbon dioxide was studied. Supercritical carbon dioxide was used in this reactive extrusion system to reduce the viscosity of the polypropylene melt phase by forming a polymer–gas solution in order to promote better mixing of the reactants. Subsequently, the effect of supercritical carbon dioxide on the level of grafting, product homogeneity, and molecular weight was evaluated. Analysis of the products revealed that the use of supercritical carbon dioxide led to improved grafting when high levels of maleic anhydride were used. The experimental results showed no evidence of an improvement in the homogeneity of the product, while melt flow rate measurements showed a reduction in the degradation of polypropylene during the grafting reaction when low levels of maleic anhydride were employed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1116–1122, 2003     

N-羟甲基丙烯酰胺熔融接枝PP的流变性能

采用熔融接枝法在双螺杆挤出机上制得接枝率为0．20％～0．85％的N-羟甲基丙烯酰胺接枝聚丙烯(PP-g-NHA),讨论了接枝物的组成、剪切应力和剪切速率以及温度对PP-g-NHA熔体流变行为、熔体黏度的影响,测定了接枝物的非牛顿指数。在相同剪切应力时,PP-g-NHA的剪切黏度比PP低,但黏流活化能比PP高。