聚醚改性聚硅氧烷的合成及其在水性涂料消泡剂中的应用

以低含氢硅油和烯丙基聚醚为原料、氯铂酸为催化剂,在无溶剂条件下合成了聚醚改性聚硅氧烷;并将其与硅膏、白炭黑、乳化剂、增稠剂等复配,制成有机硅消泡剂。探讨了加料分式及加料时间、物料配比、催化剂用量、反应温度、反应时间等对反应的影响,以及消泡剂在水性涂料中的应用性能。结果表明,合成聚醚改性聚硅氧烷的最佳工艺为:Si—H与C=C的量之比为1∶1.1、铂的加入量占物料总质量的5×10-6,聚醚滴加时间3 h、反应温度130℃、反应时间6 h,在此条件下活性氢的转化率可达82.8%。由此聚醚改性聚硅氧烷配成的有机硅消泡剂用于水性涂料中,具有优异的消/抑泡性能及良好的体系相容性。     

聚醚接枝有机硅的合成及其乳液的消泡性能

采用含氢聚硅氧烷与甲基封端聚醚为原料,在微波辐射条件下合成聚醚接枝有机硅,采用正交实验对合成工艺参数进行了优化;以聚醚接枝有机硅为主要活性组分,制备消泡剂乳液,并在不同体系温度及不同p H条件下,对消泡剂的性能进行评价。结果表明优化工艺为:含氢聚硅氧烷与甲基封端聚醚的摩尔比1∶1.2,加入质量比为10μg/g的氯铂酸为催化剂,在90℃保温反应45 min,平均转化率为95.4%。制备的消泡剂在常温到95℃,p H为2¹2条件下,具有良好的消抑泡性能。     

聚醚接枝有机硅的合成及其乳液的消泡性能

采用含氢聚硅氧烷与甲基封端聚醚为原料,在微波辐射条件下合成聚醚接枝有机硅,采用正交实验对合成工艺参数进行了优化;以聚醚接枝有机硅为主要活性组分,制备消泡剂乳液,并在不同体系温度及不同p H条件下,对消泡剂的性能进行评价。结果表明优化工艺为:含氢聚硅氧烷与甲基封端聚醚的摩尔比1∶1.2,加入质量比为10μg/g的氯铂酸为催化剂,在90℃保温反应45 min,平均转化率为95.4%。制备的消泡剂在常温到95℃,p H为2~12条件下,具有良好的消抑泡性能。     

聚醚改性硅油消泡剂的合成

以含氢硅油、聚醚为原料,三氟乙酸为催化剂制备了聚醚改性聚硅氧烷共聚物;通过不同原料对共聚物性能影响的研究,得出适宜的原料:含氢硅油的氢基质量分数1.5%,聚醚的相对分子质量2 000。通过对影响反应的温度、时间、原料质量比及催化剂用量等的考察,利用消泡、抑泡性能测试等手段,确定了合成聚醚改性聚硅氧烷的优化条件:100℃下反应10 h,m(聚醚)∶m(含氢硅油)=15∶1,催化剂用量为0.2%。     

乳液型聚醚改性有机硅消泡剂的合成及性能研究

合成了新型乳液型聚醚改性有机硅消泡剂,通过分子设计合成了消泡剂所用含氢硅油及烯丙基聚醚,含氢硅油合成的最佳条件为:催化剂占总量的2%,反应温度60℃,反应时间为6 h。通过正交试验确定了聚醚改性有机硅合成的最佳条件是:反应温度为120℃,反应时间为8 h,催化剂用量为15×10-6,转化率可达98%。其中烯丙基聚醚由亲水性聚醚A1与疏水性聚醚P1按一定比例加成,A1与P1的最佳比例为1∶2.5。最后采用复合乳化剂乳化上述聚醚改性有机硅,乳化剂用量为15%,HLB值为11.5,得到稳定的乳液型消泡剂,并对产品进行了表面性能测试。     

聚醚接枝聚硅氧烷的合成及其在金属清洗剂的应用研究

在微波条件下,通过硅氢反应合成聚醚接枝聚硅氧烷。考察了各因素对反应的影响,确定了最佳合成条件为：微波功率600w,聚氧乙烯聚氧丙烯醚醋酸酯与含氢硅油的摩尔比取1.2:1,添加质量比为10mg/kg的氯铂酸催化剂,反应40min, 在该条件下,平均转化率为94.7%。利用红外光谱和核磁共振（1H-NMR）对其结构进行了表征。以合成的聚醚接枝聚硅氧烷为原料制备出了消泡剂,将其应用于金属清洗剂中。研究结果表明：制备的消泡剂在该体系中性能稳定、抑泡效果良好,添加消泡剂后的金属清洗剂的洗涤效果良好。     

聚醚接枝聚硅氧烷的合成及其在金属清洗剂中的应用

在微波条件下,通过硅氢反应合成聚醚接枝聚硅氧烷。考察了各因素对反应的影响,确定了最佳合成条件为:微波功率600 W,聚氧乙烯聚氧丙烯醚醋酸酯与含氢硅油的摩尔比为1.2∶1,氯铂酸催化剂(以Pt质量计)添加量为每kg反应体系加入10 mg,反应时间40 min,在该条件下,平均转化率为94.7%。利用红外光谱和核磁共振氢谱对其结构进行了表征。以合成的聚醚接枝聚硅氧烷为原料制备了消泡剂,并应用于金属清洗剂中,结果表明,制备的消泡剂在该体系中性能稳定、抑泡效果良好,添加消泡剂后的金属清洗剂的洗涤效果良好。     

环氧改性水溶性硅油的合成

在氯铂酸催化下，通过低含氢硅油与不饱和缩水甘油醚、聚氧乙烯烯丙醚的硅氢加成反应，制得环氧改性水溶性硅油；采用化学滴定法测定未反应活性氢的质量分数，从而确定含氢硅油的转化率；在合成过程中采用甲苯作溶剂、正丙醇作封闭剂，可避免在中和反应后发生交联，有利于保证产品的稳定性。最佳反应条件为：催化剂用量为单体质量分数的0．0189％；不饱和聚醚与含氢硅油的量之比为1．1：1．0、反应时间4h、反应温度85℃；在此条件下，含氢硅油的转化率为97．1％。     

微波辐射下聚醚改性聚硅氧烷的合成及其乳液的性能

以含氢硅油与封端聚醚为原料,在微波辐射条件下合成出了聚醚改性聚硅氧烷,利用红外光谱对其结构进行了表征,采用均匀设计法对合成参数进行了优化,优化条件为：微波功率为650 W,封端聚醚与含氢硅油的摩尔比取1.1∶1,添加质量比为15 mg/kg的氯铂酸催化剂,于100 ℃反应30 min,在该条件下,平均转化率为96.8%。以合成的聚醚聚硅氧烷为主要活性单体制备出了消泡剂乳液,并考察了温度、pH值对制备的消泡剂性能的影响,结果表明制备的消泡剂在常温到98 ℃,酸性或碱性条件下的消泡及抑泡性能良好。     

聚醚改性硅油乳化剂的合成及其在特种有机硅消泡剂中的应用

以端烯丙基聚醚F6、含氢硅油为原料,氯铂酸为催化剂,甲苯为溶剂,合成出聚醚改性硅油(PMS),并用红外光谱对其结构进行表征。正交实验优化合成条件为:原料中Si—H与CC的量之比为1∶1.2,催化剂用量为30×10-6,反应温度100℃,甲苯质量分数30%,该条件下反应3 h,含氢硅油中Si—H的转化率达98.7%。将其与白炭黑、甲基硅油等复配,制得粒径小、分布范围窄、球状颗粒的消泡剂。该乳液在65℃下贮存稳定,在高温、不同pH值(2～13)条件下不分层、不漂油,且能保持消泡速度快、抑泡活性强的特点。在PMS用量为起泡液质量的0.06%,鼓泡速度为3.0 L/min条件下,消泡剂可在5.5 s内使高度为500 mL的泡沫迅速破裂,抑泡时间长达1 510 s。     

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。