聚丙烯酸酯无皂核壳乳液聚合反应的研究

采用无乳液聚合技术，合成了PBA／PMMA核壳结构的复合乳液，研究齐聚物用量及配比、温度，DDM对齐聚物聚合反应速率的影响，以及引发剂浓度，齐聚物浓度等因素对核壳乳液聚合速率的影响。     

PBA/PMMA核壳结构乳液聚合的动力学研究

采用重量分析法对PBA／PMMA体系核壳结构乳液聚合物动力学进行了研究，并计算了乳化剂用量，引发剂浓度与第一单体和第二单体聚合速率的定量关系。同时研究了温度对第一单体和第二单体聚合速率的影响。聚合速率，特别是第二单体的聚合速率对核壳结构的形成有很大的影响。     

引发剂对核壳型复合乳液合成及性能影响的研究

采用半连续种子乳液聚合法合成了核壳型聚丙烯酸酯复合乳液,系统考察了引发剂(过硫酸铵)用量对乳液聚合过程中单体转化率、聚合稳定性、乳胶粒粒径及其分布、乳液黏度及Zeta电位的影响,探讨了其内在影响机制,并采用红外(FT-IR)、差示扫描量热(DSC)及透射电镜(TEM)对乳胶粒的结构进行了表征。结果表明:乳胶粒的Zeta电位随着引发剂过硫酸铵用量的增加而增大;合适的引发剂用量可使合成的复合乳胶粒粒径较小且粒径分布较窄;引发剂用量较大会使复合乳胶粒在聚合过程中发生聚并,但所得乳液在贮存过程中稳定性较好;当引发剂用量为0.4%～0.8%(占单体混合物的质量分数)时,单体均能参与反应,极少有残余,并且所得乳液呈明显的核壳结构。     

无皂核壳丙烯酸酯乳液的合成与性能研究

合成了聚（丙烯酸丁酯／丙烯酸钠）[P(PA/AANa)]低聚物，并以此为乳化剂合成了聚丙烯酸丁酯（PBA）为核，聚甲基丙烯酸甲酯（PMMA）为壳的复合乳液。讨论了低聚物用量、壳层单体配比、核层交联剂的用量以及加料方式对乳液性能的影响。     

多层核壳结构丙烯酸酯乳液的粒径控制

研究了加料工艺、引发剂体系、乳化剂用量及复配比、聚合温度等因素对多层核壳结构乳胶粒子粒径的影响,采用连续滴加单体的加料工艺,选用复配乳化剂体系,在较低的乳化剂用量条件下,使用高效低温引发剂,在50℃引发聚合,合成了固含量为42%,平均粒径为64.9 nm,窄分布的具有多层核壳结构的聚丙烯酸酯乳液。     

聚合工艺对核/壳型P(MA-BA)乳胶粒径的影响

用半连续种子乳液聚合法制备了纳米级核/壳型聚(甲基丙烯酸甲酯-丙烯酸丁酯)[P(MA-BA)]乳液,保持水:单体:乳化剂:引发剂的质量比为60:40:1.5:0.3不变,考查了无丙烯酸存在下,反应温度、种子单体用量和壳层单体滴加速度等对核/壳型乳胶粒径的影响,结果表明适当提高反应温度、降低种子单体用量和降低壳层单体的滴加速度都可降低乳胶粒的粒径,当反应温度为85℃、种子单体占单体总量的10%和壳层单体滴加速度为0.23 mL/min时,可以获得粒径为74 nm,转化率为98.78%的P(MA-BA)乳液.     

核壳结构丙烯酸转移胶的合成及性能研究

以丙烯酸酯为聚合单体,采用多次预乳、分步滴加的种子乳液聚合的方法,合成具有三层结构的丙烯酸酯转移胶。研究了核壳层数、各层单体比例及璃化转变温度、乳化剂、引发剂对乳液性能的影响。结果表明:具有三层核壳结构,内到外单体Tg点分别为15℃-45℃-30℃、单体比例为60∶30∶10,用0.3%的复合乳化剂及0.3%过氧化钾为引发剂时,转移胶具有最佳性能。并采用了TEM透射电镜分析,表明采用分步滴加法合成的乳胶颗粒为三层核壳结构。     

PHMS/VAc/NMA复合乳液的动力学研究

用含氢聚甲基硅氧烷（PHMA）与醋酸乙烯酯（VAc)，羟甲基丙烯酰胺（NMA）共聚，合成出稳定的PHMS／VAc/NMA复合乳液，详细研究了该聚合体系的动力学特征，讨论了加料方式，反应温度，原料配比对聚合速率和单体转化率的影响，结果表明：采用单体连续滴加法，乳液聚合速率平缓，转化率较高，随着PHMS用量的增加，聚合速率和转化率降低，随着反应温度，NMA用量，过硫酸铵用量的增加，乳液聚合速率和单体转化率都相应增加。     

PBA/MMA-MAA核-壳型乳液聚合研究

本文以种子乳液聚合法制备了PBA／MMA－MAA核－壳型复合取合物乳液。讨论了复合聚合物时引发剂用量和补加乳化剂用量对聚合反应及乳胶粒及其分布的影响。结果表明，引发剂用量控制在0．2％（wt)，乳化剂用量在0．75％（wt)，可制得粒径分布较窄且性能良好的核－壳型聚合物乳液用于毛面剂中。     

核壳型醋丙乳液胶黏剂的制备及其性能研究

乳胶粒子形态控制是聚合物乳液研究的重要领域,几十年中在聚合物材料、涂料、胶黏剂等诸多领域的成功的应用使得核壳结构聚合物复合粒子备受关注。采用种子乳液聚合法,采用复配乳化剂体系合成了以醋酸乙烯酯为核,醋酸乙烯酯和丙烯酸丁酯为壳的乳液,并重点研究了单体滴加速率、SDS与OP-10质量比、引发剂用量对乳液性能的影响,通过透射电镜和红外光谱仪表征了乳胶粒子核壳结构的存在。     

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。