PVC膜改性助剂PVDF/PS-SO3H/GMS的制备

将聚偏氟乙烯(PVDF)和阳离子交换树脂(PS-SO3H)、单甘酯(GMS)以适当的比例充分混合均匀,经造粒机挤出即得到新型PVC膜改性助剂。最佳工艺条件为:配比PVDF/PS-SO3H/GMS为82∶14∶4,用于PVC膜混合料,PVC树脂/PVC膜改性助剂的最佳配比为85∶15,加入膜改性助剂后,膜制品的透水率得到提高,力学性能也有所改善。     

抗冲改性剂ACR/PVDF对PVC制品力学性能的影响

通过在ACR聚合过程中加入含氟单体,将氟引到ACR聚合物的骨架上,生产出了抗冲改性剂(丙烯酸酯类共聚物ACR/PVDF)。含氟单体分别选用四氟乙烯(HFE)、六氟丙烯(HFP)、偏氟乙烯(VDF),使用这种含氟ACR抗冲改性剂的可使聚氯乙烯(PVC)制品的力学性能,热稳定性,耐候性均得到提高。最佳反应条件为:含氟单体为偏氟乙烯,原料摩尔比m(VDF)∶m(甲基丙烯酸甲酯,MMA)∶m(丙烯酸丁酯,BA)为12∶40∶48。     

卫生级PVC-U给水管用胶粘剂的研制和应用

以聚氯乙烯(PVC)为基体树脂、乙酸乙酯/环己酮为混合溶剂、偶联剂为改性剂,采用溶剂法制成了一种卫生级PVC-U给水管用胶粘剂。考察了基体树脂、混合溶剂和施工方法等对胶粘剂黏度、粘接强度的影响。结果表明:当m(基体树脂)∶m(乙酸乙酯)∶m(环己酮)∶m(偶联剂)=24∶55∶120∶0.5、固化时间为16 h时,胶粘剂的综合性能良好,并且其卫生指标的实测结果满足GB/T 17219—1998标准要求;该胶粘剂是PVC-U给水管材/管件胶接用理想的胶粘剂。     

聚氯乙烯超滤膜的改性研究进展

作为世界第二大通用热塑性树脂,聚氯乙烯(PVC)应用十分广泛,且价格便宜,仅为聚偏氟乙烯(PVDF)价格的十分之一,但是在水处理过程中,PVC亲水性较差,水的渗透通量低,且易被污染,这就限制了聚氯乙烯膜在水处理中的应用。因此,有必要对PVC膜进行改性处理,以改善PVC膜材料的亲水性,提高PVC膜的抗污染性能。本文在试验研究的基础上综述了近年来PVC超滤膜亲水改性研究进展,并展望了其发展趋势。     

ChMI/MMA/HFPT共聚物提高PVC耐热性能的研究

通过N-环已基马来酰亚胺/甲基丙烯酸/六氟丙烯三聚体(ChMI/MMA/HFPT)共聚在共聚物骨架上引入氟元素,生产出聚氯乙烯(PVC)树脂的耐热改性剂。试验证明:共聚物可提高PVC树脂混合物玻璃化温度tg。维卡软化温度tv及极限氧指数(LOI),从而降低PVC耐热制品的成本。三元共聚物ChMI/MMA/HFPT的最佳配比为35/62/3(wt)。耐热改性剂加量占PVC树脂混合物10%时,可大大提高PVC制品的耐热性能。     

聚合中加入可聚合非离子硼酸酯/甲基丙烯酸甲酯/纳米碳酸钙复合材料对PVC树脂力学性能的影响

制备了可聚合非离子硼酸酯(BE)/甲基丙烯酸甲酯(MMA)/纳米碳酸钙复合材料,生产出经其改性的PVC树脂,并按管材配方混料,分析了试样的力学性能;并考察了改性PVC树脂在管材中的应用情况。结果表明:①生产BE/MMA/纳米碳酸钙复合材料的最佳工艺配比为:m(BE)∶m(MMA)∶m(纳米碳酸钙)=2∶3∶95。②BE/MMA/纳米碳酸钙复合材料的质量分数为10%时,改性PVC树脂试样的简支梁冲击强度最高。③改性PVC树脂在管材中的应用情况良好,不仅可代替普通PVC树脂,还可降低生产成本。     

PVC/HfA/MMA/nano-Al(OH)_3复合材料性能的研究

采用丙烯酸六氟丁酯(HfA)和甲基丙烯酸甲酯(MMA)在纳米Al(OH)3(nano-Al(OH)3)颗粒进行表面聚合,使nano-Al(OH)3表面成亲油性,从而与聚氯乙烯(PVC)颗粒的相容性得到提高。在PVC聚合后期加入这种改性剂,纳米粒子包覆在PVC颗粒表面,改性PVC的综合性能得到改善。最佳试验反应条件为:HfA/MMA/nano-Al(OH)3的配比为3∶5∶92,PVC聚合后期加入占改性PVC树脂含量8%的HfA/MMA/nano-Al(OH)3复合材料,制备出的改性PVC树脂混合料的力学性能和耐热抑烟性能均比空白样品大幅提高。     

氯化原位接枝含氟丙烯酸酯对PVC性能的影响

通过氯化原位接枝法制备了PVC/含氟丙烯酸酯接枝共聚物(以下简称改性PVC树脂),考察了含氟丙烯酸酯的种类和用量对改性PVC树脂性能的影响,以及改性PVC干混料加工性能的变化。结果表明:①在考察的4种含氟单体(丙烯酸三氟乙酯、丙烯酸六氟丁酯、丙烯酸八氟戊酯、丙烯酸十二氟庚酯)中,采用丙烯酸六氟丁酯生产的改性PVC树脂综合性能最好;②当m(丙烯酸六氟丁酯)∶m(PVC)=5∶95时,改性PVC树脂的综合性能较好;③改性PVC树脂的加工性能得到改善。     

BPAC-UF组合工艺对微污染原水处理效果及膜污染控制

采用生物粉末活性炭-超滤(BPAC-UF)分体式工艺的中试装置,探究该工艺对西氿微污染原水的处理效果,在此基础上对比研究聚偏氟乙烯(PVDF)和聚氯乙烯(PVC)两种材质超滤膜的膜污染情况。PVDF膜和PVC膜两种不同材质的膜组合工艺对浊度去除率均超过95%,超滤膜可保证出水浊度要求。PVDF膜对尺寸不超过2μm的颗粒物去除效果要略优于PVC膜。初期PAC未转化为BPAC时,工艺对氨氮和CODMn的去除主要靠活性炭吸附。当PAC转化为BPAC,BPAC-UF对氨氮的去除主要是通过生物作用,后期去除率稳定在80%以上,BPAC-UF对CODMn去除率不高,稳定在25%左右。在膜污染控制方面,PVDF膜和PVC膜的跨膜压差增长趋势相似,但PVC膜的跨膜压差增速要略高于PVDF膜。经过强化物理反冲洗和化学反冲洗后,PVDF膜和PVC膜的产水性能均能恢复至较优状态,且PVDF膜恢复程度略优于PVC膜。     

基于DOTP脱色的膜分离-树脂吸附集成技术研究

以聚偏氟乙烯中空纤维膜(PVDF)、阴离子交换树脂作为膜分离-树脂吸附集成技术的分离材料应用于对苯二甲酸二异辛酯(DOTP)粗酯的脱色,采用紫外可见光谱(UV-VIS)和薄层色谱扫描仪(TLCS)测试方法分析膜分离-树脂吸附集成工艺的脱色效果和机理。结果表明:PVDF中空纤维膜在30℃操作温度下有较高脱色率,主要截留掉DOTP粗酯中的胶质和大颗粒物质,阴离子交换树脂可进一步脱去DOTP粗酯中的小分子有色物质和残留颗粒状物质。DOTP粗酯经过膜分离-树脂吸附集成技术脱色处理,DOTP颜色到达产品标准要求。     

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.     

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.     

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。