聚氯乙烯管材研究进展及使用寿命评估

综述了近年来国内外聚氯乙烯(PVC)管材(硬PVC管材、抗冲改性PVC管材、氯化PVC管材)的研究进展,并对PVC管材使用寿命的评估方法进行了分析和展望。     

浅谈聚氯乙烯管材之应用

聚氯乙烯管材(UPVC管材)问世于30年代,到50年代已具有相当的规模,至今其产销量一直处于各种塑料管之首。国外在1980年～1990年的十年中,塑料管的应用量每年以8％的速度增长,是其他各类管材增长总量的四倍。1992年美国UPVC管材     

R—PVC无毒饮水管材、管件的生产技术

采用国产卫生级聚氯乙烯(PVC)树脂,对稳定体系进行流变性能试验,并选择较佳的混合、挤出和注射成型参数,在引进设备上制得无毒、质轻、连接简便和密水性强的硬质聚氯乙烯(R—PVC)饮水管材、管件。本文介绍该产品的原辅料选择、设备特点以及生产配方和成型工艺。     

国外聚氯乙烯管材发展概况

聚氯乙烯(PVC)管材问世于三十年代,到五十年代已具有相当的规模,至今,其产销量一直处于各种塑料管的首位。PVC管材的优异性能及显著的经济效益,使它在建筑、农田、矿山、污水排放等众多的领域内广泛地应用。特别是自八十年代以来,PVC管材的加工技术水平进一步提高,使各种PVC管材不断涌现,应用领域不断扩大。一、PVC管材稳步发展     

芯层发泡共挤出PVC管材

聚氯乙烯(PVC)管材生产商已开拓了排污水、和排气(简称DWV)管道市场,并经受住了树脂价格上涨的考验,占领了约60％DWV管道市场,管材直径范围为29～203mm。现在,又有一种更新的工艺使PVC管材生产商不必购买更多树脂就可生产比原来多66％的管材。     

GB/T 5836.1和GB/T 5836.2新旧版本的主要内容变化

介绍了GB/T 5836.1—2018《建筑排水用硬聚氯乙烯(PVC-U)管材》和GB/T 5836.2—2018《建筑排水用硬聚氯乙烯(PVC-U)管件》对比原版本GB/T 5836.1—2006和GB/T 5836.2—2006的主要内容变化,分析了这些变化对建筑排水用硬质聚氯乙烯管材、管件生产、使用的影响。     

聚氯乙烯管材的配方、生产和质量监测策略

首先介绍了聚氯乙烯管材配方,其次分析了管材生产的常见问题,并提出了相应的对策,最后以质量监测为切入点,围绕监测温度和方法展开了探究,为聚氯乙烯管材在我国的应用奠定良好基础。     

我国聚氯乙烯管材及型材发展状况

聚氯乙烯硬制品中管材占有最大比例,其次是型材。文简要介绍我国聚氯乙烯管材、型材的发展概况,研制应用情况及发展前景。     

高抗冲聚氯乙烯管材的研究与开发

研究了聚氯乙烯(PVC)树脂、抗冲改性剂、复合润滑剂及工艺对高抗冲聚氯乙烯(PVC-M)管材影响。结果表明:PVC树脂相对分子质量适中,粒度均匀适合PVC-M管材生产;甲基丙烯酸甲酯/丁烯/苯乙烯三元共聚物(MBS)抗冲改性效果优于氯化聚乙烯(CPE)的,用量为8份时,材料由脆性向韧性转变;复合润滑剂用量多,力学性能较差,PVC-M管材配方中复合润滑剂用量不宜超过2.5份。     

双轴取向硬聚氯乙烯管材的加工技术

简要地介绍了双轴取向硬聚氯乙烯(PVC-O)管材的成型原理、相关加工技术以及产品的技术标准.     

聚氯乙烯管道的发展前景

介绍了国内外PVC管材的发展现状，趋势及我国的相关产业政策，分析了PVC的性能特点及发展前景。     

Chemical recycling of poly(vinyl chloride): Application of partially dehydrochlorinated poly(vinyl chloride) for producing a chemically modified polymer

Poly(vinyl chloride) (PVC) pipes were chemically modified to produce a sulfonated polymer with dehydrochlorinated PVC samples as intermediates. Two intermediates were formed: (1) partially dehydrochlorinated PVC with long sequences of conjugated double bonds and (2) the product of the partial dehydrochlorination of PVC and the nucleophilic substitution of chlorine by hydroxyl groups. The IR spectra showed that the dehydrochlorinated samples were heterogeneous materials, showing different proportions of elimination products, hydroxyl substitution, and partial oxidation. Samples dehydrochlorinated with poly(ethylene glycol) with a molecular weight of 400 g/mol for 24 h and 15 min showed the highest sulfonation yield, which was related to the sulfonation mechanism occurring predominantly because of the presence of hydroxyl groups in a mixture of vinyl alcohol and vinyl chloride units. The sulfonation was confirmed by the presence of a medium‐intensity band at 1180 cm^?1, assigned to sulfonic groups. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Processability,rheology, and thermal,mechanical, and morphological properties of postconsumer poly(vinyl chloride) bottles and cables

The processability, rheology, and thermal, mechanical, and morphological properties of three different commercial poly(vinyl chloride) (PVC) compounds blended with postconsumer PVC bottles and PVC cables were examined with respect to the recycled PVC content. The addition of PVC bottle recyclates [recycled bottles (RBs)] into virgin PVC bottle (VB) and virgin PVC pipe (VP) compounds caused a progressive reduction in the average torque. No thermal degradation or color change in the RB‐blended PVC compounds used was detected through carbonyl and polyene indices from IR analysis. The rheological properties for VP compounds were more sensitive to RB addition than those of VB compounds. The extrudate swell ratio did not change with the RB content. The decomposition temperature for the VB and VP compounds increased at 60–80% RB, whereas the glass‐transition temperature was unaffected by the RB loading. The 20 and 80 wt % RB loadings were recommended for the VB and VP compounds, respectively, for the optimum impact strength, the blends showing ductile fracture with a continuous phase. At the optimum impact and tensile properties, introducing RB recyclates into the VB compounds gave better results than the VP compounds. The hardness and density of the VB and VP compounds did not change with the RB content. The RB property change was comparatively faster than that of recycled PVC pipes. Adding the PVC cable recyclate [recycled cable (RC)] to virgin PVC cable (VC) had no obvious effect on the torque value of the RC/VC blends. The decomposition temperatures of the RC/VC blends stabilized at 20–60% RC and tended to decrease at 80% RC. The ultimate tensile stress was improved by the addition of the RC compounds, whereas the hardness and density of the VC compounds were unaffected by the RC content. It was concluded that the optimum concentrations of PVC recyclates to be added to virgin PVC compounds were different from one property to another and also depended on the type of virgin PVC grade used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2738–2748, 2003     

PVC管道行业要走技术创新的路

探讨了发展中国聚氯乙烯（PVC）管道行业的战略,分析了面临的挑战和机遇。提出必须转变发展方式、调整优化结构,走技术创新的道路;防止盲目扩大产能,搞低水平的重复建设。并就如何扩展PVC管道市场和开发新产品提出了建议。     

Effect of poly(vinyl chloride) resin type in the preparation process of slush powder

During the preparation of the poly(vinyl chloride) (PVC) slush powder, we found that PVC resins obtained by different polymerization methods affected many properties of slush powder and its products. Two types of commercial PVC resins were used for slush powder preparation: mass poly(vinyl chloride) (M‐PVC) and suspension poly(vinyl chloride) (S‐PVC). We used the Haake rheomix test to characterize the absorption of plasticizers into PVC resins, and the results showed that M‐PVC absorbed the plasticizers more quickly than S‐PVC. The fusion behavior of the two slush powders was studied by the thermal plate test and Haake rheomix test, and the results showed that the slush powder of M‐PVC was easier to fuse than that of S‐PVC. The different properties of the two resins and slush powder could be explained by the morphology, average size, and size distribution. Due to the “skin” of the particles' surfaces, the wider size distribution, and the large size of particles, S‐PVC absorbed the plasticizers more slowly and was more difficult to fuse. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3331–3335, 2002     

Nonaqueous polymerization of vinyl chloride: An environmentally friendly process

Poly(vinyl chloride) (PVC) is produced via a nonaqueous polymerization process in which hexane is used as a diluent. This nonaqueous process can lead to significant energy savings, significant reductions in carbon dioxide emissions, and the elimination of wastewater. Various suspending agents have been used to evaluate their effects on the shape and morphology of PVC grains. The nonaqueous process leads to the formation of PVC grains with higher porosity than that of typical suspension PVC. The bulk density is slightly lower than that of suspension PVC, but the thermal stability seems to be similar. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of glycidylethylhexylphthalate and its effects on poly(vinyl chloride) films as a novel plasticizer

To improve the processability and prevent the thermal degradation of poly(vinyl chloride) (PVC), various plasticizers and heat stabilizers have to be compounded. Phthalic plasticizers and metal soap stabilizers are usually used with epoxides as costabilizers. Epoxidized soybean oil (ESO), is one of the most commonly used epoxides because of its typical combined roles as a plasticizer and heat stabilizer in PVC compounds. ESO, however, sometimes causes surface contamination of PVC compounds because saturated fatty acids such as stearic and palmitic acids in soybean oil easily bleed onto the surface. In addition, some ingredients in ESO with hydroxide groups and unreacted double bonds during epoxidization also tend to increase the bleeding of ESO. This is due to their low compatibility with PVC resins. In this study, a novel plasticizer of PVC resins, glycidylethylhexylphthalate (GEHP), was synthesized, and its performance was evaluated. GEHP was designed to act as a plasticizer like normal phthalic plasticizers and to act as a heat stabilizer like ESO. Through the addition of epoxy groups in phthalic compounds, the resistance to bleeding was improved, and the plasticizing and heat‐stabilizing effects on the PVC compounds were preserved. Soft PVC films were prepared with GEHP. The mechanical properties, thermal stability, and bleeding properties of the films were investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1347–1356, 2005     

Contributions to characterization of poly(vinyl chloride)–lignin blends

The present study evaluates the impact of blending organosolv and kraft lignins, which are natural polymer by‐products in the pulp and paper industry, with plasticized poly(vinyl chloride) (PVC) in flooring formulations. Also examined is the impact of replacing dioctyl phthalate, a PVC industry general‐purpose plasticizer, with diethylene glycol dibenzoate (Benzoflex 2‐45), tricresyl phosphate (Lindol), or alkyl sulfonic phenyl ester (Mesamoll) in these formulations. The influence of the different types of lignins and plasticizers on the processibility, thermal, and mechanical properties of the blends is discussed. These properties demonstrate that partial replacement of PVC (20 parts) with different lignins is feasible for some formulations that can be successfully used as matrices for a high level of calcium carbonate filler in flooring products. In addition, the data demonstrate that the presence of certain plasticizers, which interfere with the intramolecular interactions existing in lignins, may allow the lignin molecules to have more molecular mobility. The morphology and the properties of PVC plasticized lignin blends are strongly influenced by the degree and mode of the lignin plasticization and its dispersion within the PVC matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2732–2748, 2006     

Preparation and structural characterization of nanocrystalline poly(vinyl chloride)

This article describes the development of novel nanocrystalline poly(vinyl chloride) (PVC) for potential applications in PVC processes and reports improvements in the mechanical properties and thermal resistance. Before the preparation of nanocrystalline PVC via jet milling, PVC was spray‐treated and heat‐treated to improve its crystallinity. The pulverization and degradation, morphology, crystalline structure, and melting‐point changes of postmodified PVC during jet milling and the relationship between the distributions of the particle size and processing temperature were investigated. X‐ray analysis and density testing indicated increased density and improved crystallinity. The crystalline region of nanocrystalline PVC was less than 80 nm, with a particle size distribution of 5–20 μm and a melting point of less than 128°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 563–569, 2004     

PVC-U加筋管的生产工艺研究及其品质影响因素分析

采用国产设备和原料生产硬质聚氯乙烯（PVC-U）加筋管,介绍了配方、工艺流程及工艺条件的控制对产品品质的影响,对生产过程中可能出现的管肋弯曲、外壁起皮、内壁不光滑、环刚度不够、管材质脆、焦料等问题进行了研究,从加工温度、压力、螺杆转速、真空度等成型工艺入手,详细分析了各种问题的形成原因并提出了切实可行的解决方案