浅谈我公司对PVC树脂老化白度的研究

介绍了齐化化工有限责任公司对提高PVC树脂热老化白度的研究。采取的措施 :(1)单体中含铁量控制 2× 10 -6以下 ;(2 )在生产高型号PVC树脂时 ,加入可消耗高能自由基的链转移剂 ;(3)聚合转化率控制在 80 %左右时出料 ;(4 )加入 0 .0 2 %以下的C7-9Zn。改进后使PVC树脂的白度控制在 85 %、粘数为 85mL/g。     

提高PVC树脂热稳定性的研究

通过采用缓冲剂对聚合体系的pH值进行控制、在聚合配方中添加热稳定剂、控制聚合转化率等措施提高了PVC树脂的热稳定性能。结果表明：聚合开始添加用量为0．14％(或0．12％)(以VCM质量分数计)的碳酸氢铵pH值缓冲剂与聚合1．5h后流加用量为0．13％的氢氧化钠能有效地控制聚合体系pH值呈中性状态;采用加料方式2添加0．06％的PVC树脂改进剂或添加0．04％液体锌热稳定剂(或0．04％液体锌与新型耐热终止剂SPJ-KHZ复合使用)能有效提高PVC树脂的热稳定性能。     

改进PVC树脂质量 降低成本增效益

介绍了河南神马氯碱化工股份有限公司改进PVC树脂质量、降低成本采取的具体措施：(1)改进生产配方,改变分散剂、调粒剂、引发剂、pH值调节剂和终止剂;(2)采用塔式汽提装置脱除VCM,,实施上述措施后,PVC树脂的颗粒形态得到了改进,100gPVC—SG3树脂的增塑剂吸收量由平均24．25g提高到28．75g,100gPVC—SG5树脂的增塑剂吸收量由平均22．5g提高到26．5g;PVC树脂的老化白度提高约3％;节约资金32万多元/a,取得了可观的经济效益。     

表面改性纳米碳酸钙原位悬浮聚合PVC的制备与性能研究

采用湿法表面改性的纳米碳酸钙(nano-CaCO3)与VCM原位聚合,制备了nano-CaCO3原位聚合PVC树脂(简称原位PVC树脂),研究了其力学性能、加工性能、微观形貌和热稳定性等。结果表明:①nano-CaCO3能够很好地分散在PVC树脂中,对PVC基体产生很好的补强作用;与普通PVC试样相比,原位PVC试样缺口冲击强度提高到13.3 kJ/m2,效果显著;其加工性能也得到了提高。②试样冲击断面的扫描电子显微镜照片表明原位PVC试样为韧性断裂,普通PVC试样为脆性断裂。③DSC试验表明,原位PVC树脂的热稳定性优于纯PVC树脂。     

VCM回收系统中VCM过氧化物的清理

在PVC生产过程中,VCM回收装置是一个很重要的组成部分。它是把聚合过程中未反应的VCM气体回收冷凝后输送到聚合工序继续反应。河北盛华化工有限公司(以下简称河北盛华)经过多年的扩建,PVC树脂生产能力已达到10万t/a,2004年开始运行VCM回收系统,至今已3年多,目前每天回收VCM45 t左右。1回收VCM工艺流程从聚合来的未反应VCM气体经过水环压缩机压缩后,再经过2台串联的冷凝器冷凝,冷凝器用0℃盐水做冷却介质,冷凝下来的VCM储存到储罐,然后间断地送回聚合工序。未冷凝的气体回到VCM尾气回收系统。工艺指标:压缩机进口压力0~0.3 MPa,…     

PVC浆料汽提装置的改进

在VCM聚合过程中,为保证PVC树脂的质量,聚合转化率一般控制在85％左右。反应结束后,PVC树脂浆料中仍残留少部分的VCM。这部分残留的VCM,一部分存在于水中,一部分存在于PVC颗粒中。由于VCM的危害性极大,因此PVC树脂成品中残留VCM含量必须控制在规定范围内。存在于水中的VCM通过气体加热或吹扫可方便地除去;而存在于PVC颗粒中的VCM与PVC颗粒的吸附力很强,要使这部分VCM脱除,必须把浆料加热到一定温度,     

聚氯乙烯塔式汽提技术

一、概述聚氯乙烯(PVC)生产过程中,单体氯乙烯(VCM)聚合成PVC过程中,聚合率一般为85％左右,未反应的VCM,一部份在回收槽内回收,尚有1％VCM吸附在PVC粒子中,其中大部份在后处理(离心,干燥)过程中散发至大气及废水中带走,最后尚有约500ppmVCM残留在成品树脂中。     

30 m~3聚合釜PVC生产工艺技改小结

<正>唐山三友氯碱有限责任公司(以下简称唐山三友)30 m~3聚合釜PVC生产采用的是悬浮法生产工艺,普通PVC树脂的生产流程主要包括涂釜、加料、反应、回收和出料,笔者主要对加料过程中引发剂、分散剂的加入方式和出料工序管线等进行工艺技术改造,以提高30 m~3聚合釜的生产能力及PVC树脂的质量。1 30 m~3聚合釜PVC生产原理及流程简介1.1工艺原理在悬浮法PVC生产工艺中,VCM液滴分散在水相中,     

2007年聚氯乙烯题录

1影响PVC黏数测定的因素及消除方法.中国氯碱,2007(1):23-252氯乙烯合成反应热水循环系统的改造.中国氯碱,2007(1):34-363PVC阻燃抑烟的研究进展.合成树脂及塑料,2007(1):77-814PVC树脂热稳定性评价方法——刚果红法和白度法.齐鲁石油化工,2007(1):74-765乙烯氧氯化法氯乙烯技术进展.中国氯碱,2007(4):14-156耐热聚氯乙烯树脂的技术进展.中国氯碱,2007(5):13-177PVC聚合釜防粘釜技术.中国氯碱,2007(5):18-198VCM精馏控制中的几个问题.中国氯碱,2007(5):20-249PVC树脂产品杂质的影响因素及改进措施.中国氯碱,2007(5):25-2610PVC转化…     

二次注入分散剂对悬浮体系稳定性及PVC树脂形态质量的影响

讨论了在VCM悬浮聚合反应过程中,当悬浮体系处于安全允许的高聚并动态和PVC树脂外在形态质量(表观密度、增塑剂吸收量)的最佳起点时,再次加入一定量的主分散剂来增强对VCM聚合处所的最小基元———VCM形态(有相对稳定的形状)小液滴的二次保护,防止其继续聚并,由此实现了稳定悬浮体系批次状态和提高PVC树脂形态质量双赢的目的。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.