有机硅-苯丙乳液最低成膜温度的研究

采用半连续法制备了稳定的有机硅-苯丙乳液，研究了软硬单体配比和有机硅单体含量对共聚物玻璃化转变温度(Tg)和乳液最低成膜温度(MFT)的影响：并选用3种成膜助剂(TXL、DPD和二乙二醇二乙醚)分别考察了成膜助剂的种类和用量对乳液产品MFT的影响。结果表明，共聚物T和乳液的MFT呈较好的线性关系，该乳液体系MFT/Tg约为0．97；乳液产品的MFT随成膜助剂用量的增加而大幅降低，其中二乙二醇二乙醚的效果最好。     

原位乳液聚合制备聚合墨粉用含蜡苯丙复合乳液及其性能研究

采用核壳乳液聚合的方法,以苯乙烯、丙烯酸丁酯和丙烯酸为共聚单体,原位制备了聚合墨粉用含蜡苯丙复合乳液。探讨了巴西棕榈蜡用量对单体转化率、凝聚率、复合乳液粒径及其分布、Zeta电位、共聚物的玻璃化转变温度以及相对分子质量及其分布的影响。结果表明,巴西棕榈蜡的加入对聚合稳定性影响不大;随着其用量的增加,乳液粒径、Zeta电位、聚合物玻璃化转变温度降低,而相对分子质量增大。当其用量为3%(wt)时,聚合物具有较适宜的Tg和相对分子质量,分别为65.9℃和89,000。     

环氧树脂改性苯丙乳液的制备研究

采用乳液聚合法制备出环氧树脂接枝改性苯丙乳液(EP-SA),重点研究了2种不同相对分子质量的环氧树脂对接枝效率、接枝共聚物相对分子质量、乳液粒子粒径及其分布、粒子形貌、乳液涂膜耐水性的影响,结果表明:E-20环氧树脂改性苯丙综合性能更好。采用氧化还原后聚合处理以及水合肼转化后处理方法,成功地将EP-SA的残余单体浓度控制在30×10-6以下。     

降低苯丙乳液最低成膜温度的途径

对如何降低苯丙乳液的最低成膜温度（MFT）的途径进行了总结。通过改进聚合方式,调整玻璃化温度,使用增塑剂、防冻剂、成膜助剂,均可降低苯丙乳液的MFT。     

可聚合乳化剂复配体系对聚合前后苯丙乳液性能的影响规律研究

选择常规阴离子型十二烷基硫酸钠(SDS)、非离子型壬基酚聚氧乙烯醚(OP-10)以及可聚合型烯丙氧基壬基苯氧基丙醇聚氧乙烯醚硫酸铵(SE-10)乳化剂为研究对象,在复配乳化剂(OP-10/SDS、SE-10/SDS、SE-10/OP-10/SDS)体系中制备得到聚苯乙烯-丙烯酸酯(苯丙)乳液。对比研究了预乳液的稳定性,以及不同配比的乳化剂对苯丙乳液转化率、粒径、乳液稳定性(聚合稳定性、化学稳定性、冻融稳定性、贮存稳定性)以及乳胶膜耐水性等的影响规律。结果表明:3种复配乳化剂体系乳液的化学稳定性和贮存稳定性均较优异。OP-10/SDS体系乳液聚合转化率较低,但凝胶率低,冻融稳定性好,聚合物膜吸水率最高。SE-10/SDS体系转化率提高,涂膜吸水率小,随体系中SDS量的增加凝胶率降低,冻融稳定性提高。而SE-10/OP-10/SDS体系的转化率最高,但凝胶率也偏高,冻融稳定性差,吸水率随着SE-10量的减小呈增大的趋势。     

聚合工艺和单体配比对醋苯丙乳液最低成膜温度的影响

分别以醋丙、苯丙种子乳液为基础，引入第3种单体，探讨了聚合工艺和单体配比对醋苯丙核壳乳液最低成膜温度(MFT)的影响，制得了MFT低、成本也低的硬核软壳的醋苯丙核壳乳液。     

甲氧基聚乙二醇甲基丙烯酸酯改性苯丙乳液的制备及表征

采用核壳乳液聚合工艺,以苯乙烯、丙烯酸丁酯、丙烯酸和甲氧基聚乙二醇甲基丙烯酸酯(MPEGMA)作为共聚单体,制备了MPEGMA改性墨粉用苯丙乳液。通过傅里叶变换红外光谱(FT-IR)对所制备的产物进行了表征;探讨了MPEGMA的用量对乳胶粒粒径、Zeta电位、乳液稳定性、共聚物的玻璃化转变温度(Tg)和相对分子质量及其分布的影响。结果表明:MPEGMA参与了共聚反应,所制备苯丙乳液的Zeta电位绝对值均在30mV以上,具有良好的稳定性。随着MPEGMA用量的增加,乳胶粒粒径增大,聚合物的Tg降低,相对分子质量下降,分布变宽。当MPEGMA的用量为4.0%(wt)时,制备了适合墨粉用的苯丙树脂,此时聚合物的Tg、数均相对分子质量及其分布指数分别为72.1℃、51000g/mol和2.97。     

剥离型蒙脱土/复合苯丙乳液的制备及其性能研究

在剥离态Na-MMT（钠基蒙脱土）悬浮液中,以原位乳液聚合法制备剥离型Na-MMT/苯丙复合乳液,通过红外光谱表征复合乳液的组成,研究了Na-MMT含量对复合乳液乳胶粒粒径、转化率、聚合稳定性和存稳定性的影响,通过热重和吸水率表征Na-MMT/苯丙复合乳液的抗水性和耐热性。实验结果表明：Na-MMT质量分数在3.0%以内有利于制备得到稳定性良好的复合乳液,复合乳液乳胶粒粒径和复合乳液涂膜吸水率均先减小后增大,Na-MMT质量分数为3.0%的复合乳液耐热性比苯丙乳液提高30℃。     

复合阳离子乳化剂聚合苯丙乳液性能研究

本文采用常规苯丙体系加入复合阳离子乳化剂AC-1812∶AC-1815∶CTAB=1∶1∶2研究体系,探讨该体系在预乳化搅拌速度以及不同预设Tg温度下的乳液性能。在该复合乳化剂体系下,预乳化搅拌转速在400rpm时为最佳。预设Tg从-5℃到25℃过程中,当设置的Tg温度升高时,硬单体增加,乳液的耐醇性能等都在提高,同时其涂膜硬度从2H升到了5H,吸水率降低了53.6%。另外,所得乳液的涂层的附着力达到0等级以及涂层有50 kg/cm的抗冲击性,并且在Tg为20℃时,乳液有较好的成膜性。     

核-壳苯丙微乳液最低成膜温度的研究

通过核-壳微乳液聚合技术合成了具有较高玻璃化转变温度(Tg)的苯丙微乳液,研究了核-壳单体用量比、壳单体组成、交联剂、聚合物极性对乳液最低成膜温度(MFT)的影响;同时比较了三种成膜助剂对乳液MFT的作用。研究发现,成膜温度随核-壳比的增大而上升;交联剂羟甲基丙烯酰胺(NMA)能有效地降低成膜温度;醇酯—12是一种良好的成膜助剂,同一成膜助剂对极性不同的乳胶粒子MFT的降低效果明显不同。     

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。