塑料膜复合用水性丙烯酸胶黏剂的研究

采用乳液聚合法制备了一种水性丙烯酸胶黏剂,可用于塑料膜的复合。研究了功能单体、乳化剂、引发剂对胶黏剂性能的影响。结果发现,软/硬单体比例为60/40~65/35,功能单体AA与HEA占丙烯酸单体用量的5%,乳化剂占丙烯酸单体用量的1%～2%,引发剂占丙烯酸单体用量的0.6%,得到的乳液胶黏剂性能最佳,其剥离强度最高可达1.8N/15mm。     

乳液型纸塑复合胶粘剂的研制

以丙烯酸丁酯、丙烯酸异辛酯、醋酸乙烯酯为主要原料,以丙烯酸为功能单体,采用预乳化种子乳液聚合法成功合成了性能优良的醋丙乳液纸塑复合胶粘剂。讨论了单体的选择、VAc用量、引发剂、乳化剂以及功能单体的用量等因素对乳液性能的影响。研究结果表明,VAC用量为45～50％,乳化剂用量为单体总量的3‰功能单体用量为6％时,制备的乳液具有较好的纸塑粘接性能。     

聚醋酸乙烯酯共聚乳液的改性研究

以醋酸乙烯酯为原料,聚乙烯醇为保护胶体,丙烯酸、丙烯酸丁酯为改性单体,研究了单体配比、引发剂、乳化剂用量和温度对醋酸乙烯酯共聚乳液性能的影响。研究表明,当丙烯酸丁酯与醋酸乙烯酯的质量比为12/30,引发剂的质量分数为0.15%,乳化剂的质量分数为0.3%,在反应温度为75℃时,可制得性能优异的聚醋酸乙烯酯胶粘剂,其T型剥离强度和耐水性能可达105 N/25mm和67 N/25mm。     

醋酸乙烯酯-大豆蛋白接枝共聚乳液胶黏剂的研制

以尿素和亚硫酸钠改性大豆蛋白,与醋酸乙烯酯等复合单体在过硫酸铵引发下进行接枝共聚,合成了性能较好的醋酸乙烯酯-大豆蛋白接枝共聚乳液胶黏剂,降低了原料成本.研究了不同反应条件对乳液胶黏剂性能的影响,优化的反应条件是以聚乙烯醇作保护胶体,采用半连续乳液聚合工艺,复合单体与大豆蛋白比例为3.0:1,引发剂用量1.2%(占单体质量),反应温度控制在70～75℃,共聚时间4.5h,制备的乳液胶黏剂具有最大剪切强度和良好综合性能.     

纸塑覆膜乳液胶的研制

以丙烯酸丁酯(BA)、醋酸乙烯酯(VAc)为主要原料,采用乳液聚合制备了一种纸塑(BOPP)覆膜胶粘剂。探讨了醋酸乙烯酯(VAc)、丙烯酸(AA)、甲基丙烯酸-β-羟乙酯(HEMA)、聚乙烯醇(PVA)、pH值缓冲剂、引发剂、乳化剂等对胶粘剂性能的影响。结果表明,当单体配比m(BA)∶m(VAc)∶m(AA)∶m(HEMA)∶m(PVA)=50∶40∶4∶4∶2,乳化剂的用量为单体量的0.8%,pH值缓冲剂用量为1.0%,引发剂用量为单体总量的0.8%时,由覆膜乳液胶粘接的纸/BOPP复合制品的剥离强度可达到0.1 kN/m以上,油墨的转移率可达90%以上。     

环氧改性苯丙乳液的制备与性能研究

采用半连续种子乳液聚合法制得环氧改性苯丙乳液。研究了环氧树脂、功能单体、引发剂、乳化剂用量对乳液性能的影响。结果表明：环氧树脂用量为单体总量的9％,丙烯酸用量为单体总量2％,硅烷偶联剂A151用量为单体总量的1．5％,引发剂用量为单体总量的0．5％,乳化剂用量为单体总量4％的时得到的乳液具有优良的综合性能。     

多组分聚醋酸乙烯酯乳液胶粘剂的制备

以丙烯酸丁酯为软单体、醋酸乙烯酯为硬单体、丙烯酸为交联剂、过硫酸钾为引发剂、十二烷基硫酸钠(SDS)+聚乙二醇辛基苯基醚(OP-10)为复合乳化剂,采用半连续种子乳液聚合法制备得到多组分聚醋酸乙烯酯乳液胶粘剂,并研究了复合乳化剂质量比、过硫酸钾用量、软硬单体质量比和丙烯酸用量对聚醋酸乙烯酯乳液性能的影响。结果表明,在单体质量占体系总质量的30%(丙烯酸丁酯与醋酸乙烯酯质量比1∶6、丙烯酸用量1%)、过硫酸钾用量为0.5%~0.6%、复合乳化剂(SDS与OP-10质量比1∶15)用量为2.5%时,制备得到的多组分聚醋酸乙烯酯乳液胶粘剂性能最好。     

聚醋酸乙烯酯乳液合成工艺的研究

介绍了聚醋酸乙烯酯乳液的合成工艺 ,主要考察了单体、乳化剂、引发剂、反应温度及聚乙烯醇对乳液粘度、固含量的影响。当反应温度为 75℃ ,乳化剂、引发剂用量分别为单体总量的 0 .15%和 0 .6 %条件下 ,得到粘度为 5 .8Pa·s、固含量为 4 2 %、pH值为 6～ 8,带蓝光的乳白色聚醋酸乙烯酯乳液。     

生产工艺参数对聚醋酸乙烯酯乳液黏度的影响研究

考查了聚醋酸乙烯酯乳液生产工艺参数如醋酸乙烯酯单体活性度、保护胶体聚乙烯醇、引发剂以及乳化剂用量、搅拌速度、pH值调节剂和反应温度对乳液黏度的影响.实验结果表明,要制备目标使用黏度(25℃)为4 000 mPa·s左右的聚醋酸乙烯酯乳液,其优化的配方和工艺条件为:单体活性度600 s;聚乙烯醇缩醛化改性;引发剂用量为单体的0.2%(其中前期种子聚合的加入量为总量的20%);乳化剂用量为单体的1.6%;聚合反应初期和后期都需加入pH值调节剂;搅拌线速度为0.6 m/s;种子聚合温度65℃,反应温度75℃.     

VAC/AA共聚乳液胶粘剂的合成与性能研究

本文介绍了醋酸乙烯酯—丙烯酸共聚乳液胶粘剂的合成与性能 ,研究了聚乙烯醇缩醛化和复合乳化剂体系对乳液稳定性和抗冻性的影响及引发剂用量和聚合保温时间与转化率的关系 ,同时还研究了丙烯酸含量对粘接强度的影响及 PH值与共聚乳液粘度的关系。结果表明 ,通过聚乙烯醇缩醛化和复合乳化剂体系 ,提高了乳液聚合稳定性和耐寒性 ;丙烯酸单体的引入 ,提高了乳胶的粘接强度 ,同时由于丙烯酸功能性基团的自增稠作用 ,可适当调节乳液的粘度以满足多方面要求     

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。