聚氯乙烯的高性能化

PVC与PE、PS、PP作为四大通用树脂受到广泛应用。本文按最近的市场动向与要求品质,叙述PVC的高性能化和特殊化等。 1.通用PVC PVC可由本体聚合、悬浮聚合、乳液聚合的三种聚合方式制造。目前日本所制造的通用PVC大部分是用悬浮法聚合的。悬浮法PVC的高性能化是以在聚合过程中控     

PVC聚合釜技术特性及全流通PVC聚合釜

介绍了国内外PVC聚合釜的发展状况,对比分析了传统PVC聚合釜与全流通PVC聚合釜的结构特性、生产强度及防粘釜技术等。指出大型聚合釜的正常运转是以很高的控制水平为前提的。     

提高LF30-Ⅱ型PVC聚合釜产能的研究

通过对LF30-Ⅱ型PVC聚合釜冷模试验数据进行分析整理,提出了LF30-Ⅱ型PVC聚合釜搅拌器结构尺寸的改进方案。生产实践结果表明,改进后的LF30-Ⅱ型PVC聚合釜达到了预期的效果,提高了聚合釜的产能,可使单釜PVC生产能力达到10 000 t/a以上。     

本体法PVC生产技术及其发展趋势

介绍了国内外本体法PVC的生产概况,比较了本体法PVC与悬浮法PVC的聚合机制、生产工艺及加工性能,指出三步本体法聚合工艺和连续本体法聚合工艺是今后的发展方向。     

127 m3和135 m3 PVC聚合釜生产能力及技术比较

对中国石化齐鲁股份有限公司氯碱厂1978年引进的日本信越化学工业株式会社127 m3PVC聚合釜的运行情况和2002年引进的美国西方化学公司的135 m3PVC聚合釜的运行情况进行了比较和分析,结果表明:135 m3PVC聚合釜的主要技术参数优于127 m3PVC聚合釜,可大幅度地降低建设投资和产品的生产成本,获得较大的经济效益。如果纯粹从技术的角度考虑,135 m3PVC聚合釜将是今后发展的方向。     

降低PVC聚合助剂成本的方法

介绍了上海鄂尔多斯工业技术有限公司通过采取调整PVC聚合配方、自产助剂、降低助剂采购价格等方法降低PVC聚合工段助剂成本,PVC聚合工段助剂成本从120元/t降至90元/t左右(不含税),PVC树脂优等品率上升为≥96%。     

LF48型PVC聚合釜的研制及发展

介绍了LF48型悬浮法PVC聚合釜的技术性能、结构特点、工艺难点及加工方法，并在实际应用中通过不断改型很好地满足了各PVC生产厂的需要。实践证明：LF48型PVC聚合釜是目前中小型规模PVC生产厂的首选釜型，已逐渐取代LF30型PVC聚合釜。     

105m^3聚合釜聚合中途注低温水PVC生产工艺

介绍了聚合中途注低温水工艺在105m^3聚合釜PVC生产中的应用情况。运行情况表明：中途注低温水工艺对PVC产品质量没有影响,SG5型PVC树脂聚合反应时间可缩短近50min,提高了聚合釜的生产能力。     

聚氯乙烯纳米复合材料研究进展

阐述了共混法、原位聚合法和插层聚合法等聚氯乙烯(PVC)纳米复合材料的制备方法,介绍了PVC/无机粒子、PVC/黏土等几种纳米复合材料的性能,指出了PVC纳米复合材料的发展方向。     

铁离子对氯乙烯悬浮聚合反应的影响规律

在确保氯乙烯聚合试验过程可重复,试验数据可信的前提下,研究了铁离子含量对聚合时间、PVC树脂的白度与热稳定性的影响规律,发现铁离子会延长聚合时间,降低PVC树脂的白度与热稳定性,进一步获得了聚合时间、PVC树脂白度及热稳定时间随铁离子含量的变化关系。     

高聚合度聚氯乙烯弹性体阻燃性能的研究

研究了高聚合度聚氯乙烯树脂与增塑剂及阻燃剂共混弹性体材料的阻燃性能。结果表明,高聚合度聚氯乙烯材料的强度高于低聚合度的聚氯乙烯,阻燃剂的含量在１０份左右时弹性体材料的氧指数可超过３０。     

新型离子液体交换法合成阻燃剂及其应用

为了开发出一种合成简单、便于保存,且不会对环境造成污染的阻燃剂,以双咪唑离子液体为单体,通过活性聚合反应和阴离子交换反应合成了磷氮膨胀型阻燃剂聚1-丁基-3-(1-乙烯基咪唑-3-己基)咪唑磷酸氢盐和聚1-丁基-3-(1-乙烯基咪唑-3-己基)咪唑磷酸二氢盐,研究了不同阻燃剂与聚氯乙烯的比例对聚氯乙烯电缆料极限氧指数的影响。结果表明:随着体系中阻燃剂与聚氯乙烯的质量比从1∶5到4∶9,聚氯乙烯电缆料的极限氧指数可从28%提高到34%;并且同等比例下,聚1-丁基-3-(1-乙烯基咪唑-3-己基)咪唑磷酸氢盐对极限氧指数的提高要优于聚1-丁基-3-(1-乙烯基咪唑-3-己基)咪唑磷酸二氢盐。     

A review of vinyl technology

This is a review of PVC technology from chlorine and ethyle, to PVC polymerization, to melt processing, to properties, to recycling and environmental concerns. It is written in terms for understanding by even non-scientists in the industry. PVC has a large sales volume, second only to polyethylene. Its high chlorine content provides it with a very high level of combustion resistance for building products, electrical enclosures, and wire & cable insulation. PVC has a unique ability to be compounded with a wide variety of additives, making it possible to produce materials in a range from flexible elastomers to rigid compounds, materials that are weatherable such as for siding and windows, compounds that have stiff melts and little elastic recovery for outstanding dimensional control useful in profile extrusion, or low viscosity melts, which compete effectively with ABS and PC/ABS in thin walled injection molding parts such as computer monitor housings. Some of PVC's properties are attributed to unique structures. The polymer precipitates from its monomer and grows into primary particles, which are later the melt flow units. Fusion into larger structures and product strength are controlled by break-down of the grains into primary particles, by the choice of additives, by the amount of melting (temperature), and by the number of tie molecules (molecular weight). The main type of polymerization is the suspension process, with significant polymerization made by the mass process and emulsion process. In the suspension process, the polymerization takes place in droplets of monomer suspended in a water. PVC is environmentally sound. With over 50% chlorine content, chlorine makes PVC one of the most energy efficient polymers, makes PVC inherently flame retardant, and acts as a marker, enabling automated equipment to sort PVC containers from other plastics in the waste stream. Analysis from 155 large-scale, commercial incinerator facilities found no relationship between the chlorine content of waste nor the addition of PVC, and dioxin emissions from combustion processes. New requirements from the U.S. EPA make scrubbers mandatory on all incinerators and are necessary whether or not PVC is present in the waste feed.     

Recent research advances in the chemistry of poly(vinyl chloride)

Summarized briefly here are some new observations that relate to the polymerization chemistry of vinyl chloride (VC) and to the thermal degradation, thermal stabilization, fire retardance, and smoke suppression of poly(vinyl chloride) (PVC). During polymerization, head-to-head VC emplacement leads to β-chloroalkyl radicals that can transfer chlorine atoms directly to VC. Another mechanism for transfer to monomer is responsible, however, for the polymer molecular-weight reductions that occur at high VC conversions. This transfer process involves the abstraction of methylene hydrogen from the polymer by an ordinary macroradical and the subsequent bimolecular donation of a chlorine atom to VC. The propagation steps of the polymerization do not become diffusion-controlled at VC conversions near 90%, and hydrogen abstraction from the polymer by ordinary macroradicals leads to the structural defects that cause thermal instability. The thermal dehydrochlorination of PVC involves ion pairs or four-center concerted transition states that are highly polarized. Reversible thermal stabilization of the polymer by organic metal salts occurs by the Frye-Horst process, and the reductive coupling of PVC chains may suppress both smoke and flame. This coupling can result from reactions of the polymer with zero- or low-valent transition-metal species that are formed in situ from appropriate additives.     

PVC/ABS合金的研究

研究了聚氯乙烯/丙烯睛-丁二烯-苯乙烯三元共聚物(PVC/ABS)塑料合金的耐候性、ABS与PVC的相容性、力学性能和阻燃性能。试验结果表明,PVC的加入可有效提高ABS的耐候性,PVC/ABS合金体系在ABS与PVC不同比例时均有良好的相容性;在一定区域内合金体系力学性能会出现极大值,极值随ABS和PVC类型不同,出现位置亦不同;PVC的加入可明显提高ABS的极限氧指数(LOI),但要达到UL94V-0级阻燃性必须添加阻燃剂。     

纳米阻燃抑烟PVC的研究进展

PVC是一种应用广泛的高分子材料，但因其具有热稳定性差、易燃烧、发烟量大的缺点而限制了发展，因此PVC的阻燃与抑烟成为阻燃科学研究领域的关键问题之一。纳米型阻燃抑烟剂克服了传统型阻燃抑烟剂添加量大、阻燃抑烟效果不明显的缺点，为研究和解决PVC阻燃抑烟提供了一个新途径。本文介绍了PVC纳米阻燃抑烟剂的制备方法、表征手段及其在PVC中的应用以及PVC降解、阻燃与抑烟的表征，最后简要论述PVC阻燃抑烟的发展趋势。     

电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。     

超低聚合度PVC树脂制备及特性

$ 简述了超低PVC树脂制备要点,探讨了物性指标和特性。发现超低PVC树脂凝胶化温度低,加工流动性好,熔融因数(F)值高。制品表面光洁度、透明度、热稳定性和阻燃性优良;与其他高分子材料有较好相容性和“分子内增塑”作用,共混改性后替代ABS等工程塑料,能降低成本,有较高实用价值和经济效益。     

无机阻燃剂在增塑聚氯乙烯中的应用

详细介绍了无机阻燃剂的阻燃机理，研究了各种无机阻燃剂对增塑聚氯乙烯性能的影响，同时发现了它们在阻燃方面的协同效应作用。     

PVC阻燃抑烟的研究进展

介绍了聚氯乙烯(PVC)的热降解机理及燃烧特性。综述了PVC阻燃抑烟剂(如阻燃增塑剂、金属化合物、含硼阻燃剂、微胶囊红磷和无机填料等)的研究,特别提及了一些过渡金属(如Mo、Cu与Fe的化合物)在PVC抑烟中的明显作用。比较了各种阻燃抑烟方法的优缺点。采用阻燃剂和抑烟剂复合对PVC协同阻燃抑烟是未来的研究方向。