着色剂在PVC压延膜中的应用

概述了聚氯乙烯压延膜的特点和优点;针对PVC压延工艺的特殊要求,总结了PVC压延膜对颜料的特殊要求;介绍了PVC压延膜中常用的无机和有机颜料及使用注意事项。     

受阻酚类抗氧剂在高分子领域的研究进展

综述了受阻酚类抗氧剂的种类及其抗氧化作用机理、抗氧化效率的影响因素,并展望了受阻酚类抗氧剂的发展趋势。目前,受阻酚类抗氧剂主要向高稳定性、高抗氧化效率及环境友好的目标发展。提高硫代受阻酚类抗氧剂的相对分子质量及合成反应型硫代受阻酚类抗氧剂将成为研究重点。单酚类抗氧剂与超细粉体接枝将成为重点研究方向。改变抗氧剂骨架结构,简化合成工艺,降低成本,提高与基体的相容性及抗氧化效率将成为多酚类抗氧剂的研究重点。     

聚氯乙烯压延加工过程中影响因素的分析与探讨

随着压延加工应用领域的不断增加，压延加工工艺也得到了相关部门的高度重视。从我国目前压延加工的制品种类来看，主要包括橡胶、人造革、硬质PVC和软质PVC几种，根据制品种类的不同，在压延加工过程中所产生的影响因素也不尽相同。本文通过对聚氯乙烯（PVC）压延加工过程中的影响因素进行分析和探讨，并在此基础上简述如何提高聚氯乙烯压延加工质量，为今后聚氯乙烯压延加工工作提供一定的参考依据。     

PVC耐候环保型助剂的应用研究

选取4种具有代表性的终止剂（水溶型终止剂1、油溶型终止剂2、乳液抗氧剂型终止剂Upack B7032D和悬浮抗氧剂型终止剂U-pack B245D）,从物理性能、环保性、终止效率、PVC树脂的老化白度和热稳定时间等多个角度进行详细对比研究,最终选取PVC聚合环保性好、终止效率高、PVC树脂老化白度高、热稳定时间长的终止剂U-pack B245D,为PVC生产企业选择终止剂提供参考。同时,研究了不同种类光稳定剂对PVC压延膜耐候性的影响,利用Q-Lab QUV/Spray紫外荧光老化试验箱模拟室外老化条件对PVC压延膜进行耐光老化测试,筛选出耐候性最好的光稳定剂U-pack UV-7917,为PVC压延膜的室外耐候性使用提供依据。     

汽巴精化PVC行业用新型添加剂

PVC是最重要的热塑性聚合物之一,每年的产量和加工量接近2500万t。PVC的应用范围广,能和多种聚合物共混改进自身的物理机械性能。酚类产品,特别是受阻酚广泛用于PVC行业。新近开发的高效光稳定剂和其他功能性添加剂(抗菌、抗静电、防雾和荧光增白剂等)增强了PVC制品的品质,因此强化了PVC应用在市场中的地位。1受阻酚抗氧剂1.1PVC聚合中的链终止剂和抗氧剂理想的链终止剂必须能完全终止聚合反应,猝灭任何催化剂残留(自由基) ,以防止在生产中的过度聚合。从而,减少了停机清理的时间,提高了生产率。IRGANOX1141是两种受阻酚的协效复…     

PVC压延膜生产中需要注意的事项

PVC压延膜是通过压延工艺制得,是将受热的PVC塑料通过一对或多对相向旋转的水平辊筒的间隙,使物料承受挤压、延展作用,而成为具有一定厚度、宽度和表面光滑的薄型制品的过程.特点是产量高,质量好.在PVC压延膜生产中需要注意以下事项.     

镇江开发出抗氧剂1425

镇江市前进化工厂开发成功钙盐抗氧剂1425。 该产品是一种分子量较大的含磷受阻酚类高效抗氧剂。采用该产品生产的高分子材料制品,能长期保持制品色泽,可拓宽制品的应用领域,它与辅助抗氧剂168组成的复合抗氧剂。可广泛用于聚丙烯、聚酯纤维等制品。镇江开发出抗氧剂1425     

非对称型受阻酚类抗氧剂的研究新进展

非对称型受阻酚类抗氧剂以其特殊的结构显著提高了聚合物的抗氧化效率,新型非对称型受阻酚的探索与开发代表了当今世界聚合物抗氧化领域的一大发展趋势。简述了非对称型受阻酚类抗氧剂的结构特性及抗氧化机理,重点介绍了几种典型的半受阻酚类抗氧剂的合成及应用,指出了非对称型受阻酚类抗氧剂的研究方向。     

抗氧剂对PP化学降解及其热稳定性的影响

研究了PP挤出降解反应时抗氧剂和过氧化二叔丁基之间发生的反应。试验结果表明:受阻酚类抗氧剂与酯类抗氧剂配合组成的复合抗氧剂,具有良好的协同稳定效果;选择合适的降解温度,采用抗氧剂母料的混合方式,可提高PP的降解效果、热性能和加工稳定性。     

关于PVC降解与稳定的研究(续)

三、PVC稳定的机理 在已认识PVC降解机理及其影响因素的基础上,使我们认识到PVC的稳定性是可以通过某些措施得到改进的,其中包括添加某些化学助剂于聚合反应过程及其加工过程而获得改进,这种改进PVC稳定性的助剂称为稳定剂,其中包括热稳定剂、光稳定剂、抗氧剂及润滑剂等。现就树脂加工过程中所使用的不同性质的助剂,对于改进PVC     

Effect of Wood Flour Content on the Thermal,Mechanical and Dielectric Properties of Poly(vinyl chloride)

Several composite formulations of poly(vinyl chloride)/olive wood flour (PVC/WF) were manufactured by dry‐blending PVC, wood flour, plasticizer and other processing additives in a high‐intensity mixer. The dry‐blended compounds were calendered into film samples (T = 180°C, calendered time = 8 min). The films obtained are cut into normalized samples for thermal, mechanical, and dielectric characterization. The results obtained show that stress as well as strain at break decrease sharply as the wood flour content increases. On the other hand, this filler content has little influence on the glass transition temperature. It decreases the temperature of decomposition setting and retards the PVC thermal decomposition. It increases permittivity as well as dielectric losses. The thermal stability, as measured by thermogravimetry (TGA) and differential scanning calorimetry (DSC) methods, is good enough to permit processing of these types of PVC compounds using conventional processing techniques and temperatures under 210°C.     

Role of pigments in the stability of polyethylene systems

The photodegradation processes of high‐density polyethylene (HDPE) films containing either a phthalocyanine‐based pigment, or a rutil (TiO₂)‐based pigment, as well as of the unpigmented films stabilised differently were investigated during photo‐ageing, applying mechanical, gel content and XPS measurements. The phthalocyanine pigment‐containing film showed degradation characteristics (abrupt decrease of elongation at break after short irradiation period, no gel formation, high concentration of oxygen‐containing functional groups on the surface) similar to those of the films containing a low amount of stabiliser. The behaviour of the TiO₂‐containing film and that of the unpigmented films containing a higher amount of stabiliser were also similar (slow decrease of elongation at break, increase of gel content, lower amount of oxygen‐containing functional groups on the surface). The concentration of oxygen‐containing functional groups in samples pigmented with phthalocyanine increased remarkably with increasing processing temperature. The results suggest that the phthalocyanine pigment influences the photostability indirectly, through reduction of the thermal stability of polymer due to the adsorption of the thermal stabiliser by the phthalocyanine pigment. Coating the surface of phthalocyanine with reactive surfactant improved the photostability of the HDPE film.     

PVC压延膜生产技术

介绍了PVC压延膜的特性、主要生产原料、生产工艺流程、生产设备,以及生产中的注意事项和常见质量问题。     

Processing and formulation effects on gel levels in flexible PVC extrusions

Gels, or fisheyes, in flexible PVC extruded or calendered products are the ～ 150 μm PVC grains which, for one reason or another, survive the compounding and processing steps to appear as defects on the surface of the profile, sheet, or film. In most applications they are aesthetically objectionable. In other applications, such as medical tubing or blood bags, they are functionally intolerable. Gels are a function of resin and plasticizer selection, processing temperature, residence time at temperature, and shear history. In flexible PVC extrusion, process parameters include cube or pellet versus powder processing, barrel L/D, screw compression ratio, screw RPM, and temperature profile. Choice of resin is, of course critical. Resin morphological parameters of importance include friability, porosity, and absence of glassy particles. Plasticizers vary greatly in their ability to solvate the PVC grain. Various types of dry blend and resin contamination result in large increases in gels.     

Influence of the chemical structure of para-bridged group on the antioxidant behavior of hindered phenol antioxidants in HDPE resin

A hindered phenol antioxidant with rigid para-bridged group (antioxidant AP) was synthesized to study the effect of the chemical structure on the antioxidant properties of hindered phenol antioxidants in high density polyethylene (HDPE). Antioxidant behavior of series of hindered phenol antioxidants with different para-bridged groups in HDPE resin was also investigated by the thermal oxidation experiment, the mobility test, and the long-term accelerated thermal aging test. The results showed that the rigidity of para-bridged group and the molecule size have the important influences on the antioxidant performance of hindered phenol antioxidants in the HDPE resin, and the antioxidant abilities of antioxidant AP and Irganox 1,330 with the aryl para-bridged group was superior to Irganox 1,098 and 1.0G dendritic antioxidant with the alkyl para-bridged group at the same testing conditions. Compared with the hindered phenol antioxidants with alkyl para-bridged group, the hindered phenol antioxidants with aryl para-bridged group have better thermal oxygen stability and less mobility in the HDPE resin. Irganox 1,010 with ester groups is prone to hydrolysis to increase the mobility rate in hot water and the migration resistance of hindered phenol antioxidants in n-hexane. Moreover, the high content of phenolic OH group and the aryl para-bridged group are favorable for improving the antioxidant performance of hindered phenol antioxidants.     

Thermo‐oxidative stabilization of poly(lactic acid)‐based nanocomposites through the incorporation of clay with in‐built antioxidant activity

In this work, an innovative approach to overcome the issue of the poor thermo‐oxidative stability of polymer/clay nanocomposites is proposed. Specifically, biodegradable poly(lactic acid) (PLA)‐based nanocomposites, containing organo‐modified clay with in‐built antioxidant activity, were prepared. Through a two‐step chemical protocol, a hindered phenol antioxidant was chemically linked to the ammonium quaternary salt which was then intercalated between the clay platelets [(AO)OM‐Mt]. The nanocomposites were characterized and their thermo‐oxidative stability during melt processing and under long‐term thermal test conditions was investigated. PLA nanocomposites containing the (AO)OM‐Mt showed higher oxidative stability, along with better clay dispersion, compared to PLA‐nanocomposites containing commercial clay and a free hindered phenol antioxidant. Obtained results can be explained considering that (AO)OM‐Mt may act locally, at the interface, between the silicate layers and the polymer macromolecules, thus contributing to the observed improved stability of the polymer both during processing and under long‐term thermal‐oxidative conditions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44974.     

聚氨酯涂料的配方设计及PVC计算

采用羟基丙烯酸树脂为成膜物质,钛白粉、超细硫酸钡为颜填料,配用合适的助剂和溶剂,制备了高光泽、耐候性优异及低成本的聚氨酯涂料。考察了颜基比(P/B)、填料、催化剂及紫外线吸收剂对漆膜性能的影响。通过单一颜料涂料体系的颜料体积浓度(PVC)的计算,推导出PVC的倒数与P/B的倒数呈一次线性函数关系。     

New process stabilization system for emulsion polymerized ABS

In emulsion polymerized acrylonitrile-butadiene-styrene (ABS), an antioxidant system is added to the latex prior to coagulation. The antioxidant protects the polymer against the high temperatures encountered during drying and processing. Traditionally, hindered phenols have been used in combination with a co-stabilizer, such as tris-nonylphenylphosphite (TNPP) or dilaurylthiodipropionate (DLTDP). This paper discusses an antioxidant stabilization system based entirely on hindered phenol chemistry. This system provides excellent performance compared to the traditional systems without the presence of a phosphite or sulfur based costabilizer. In addition, the new antioxidant system is a liquid allowing for ease of emulsification and handling.     

Photoaging and stabilization of rigid PVC/wood‐fiber composites

Ultraviolet (UV) weathering performance of unpigmented and rutile titanium dioxide pigmented rigid polyvinyl chloride (PVC)/wood‐fiber composites has been studied. The composite samples were manufactured by dry‐blending PVC, wood fibers, and other processing additives in a high‐intensity mixer. The dry‐blended compounds were extruded and compression molded into panel samples. The manufactured samples were artificially weathered using laboratory accelerated UV tests. Composite samples were exposed to 340‐nm fluorescent UV lamps and assessed every 200 h, for a total of 1200 h of accelerated weathering. Each assessment consisted of a visual examination of surface roughness or erosion, a contact angle measurement, a FTIR collection, and a color measurement. The experimental results indicated that wood fibers are effective sensitizers and that their incorporation into a rigid PVC matrix has a deleterious effect on the ability of the matrix to resist degradation caused ultraviolet irradiation. The light stability of these composites could be improved quite efficiently with the addition of rutile titanium dioxide photoactive pigment during formulation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1943–1950, 2001     

双组分水性聚氨酯涂料的制备与性能测试

选用水性羟基丙烯酸分散体为成膜物质,水可分散型异氰酸酯（HDI三聚体）为固化剂,以钛白粉为颜料,搭配合适的助剂,制备了干燥快、光泽高、耐候性优异及低成本的双组分水性聚氨酯涂料。考察了颜基比、固化剂的量对涂膜性能的影响,通过涂料体系颜料体积浓度的计算,推导出PVC的倒数与P/B的倒数呈一次线性函数关系。