VAc/MA/AA三元无皂乳液共聚的研究

以过硫酸钾(KPS)为引发剂,对VAc/MA/AA三元无皂乳液共聚进行了研究。探讨了引发剂用量、功能单体用量(AA)对乳液稳定性、胶乳粒子粒径、粒径分布及胶乳粘度、粘接强度等性质的影响。结果表明: 引发剂用量小于单体总质量的0．7％时,随着KPS用量的增加,胶乳粒子粒径减小,粒径分布变窄;引发剂用量大于单体总质量的0．7％时,随着KPS用量的增加,胶乳粒径及分布都增大,KPS用量为单体总质量的6％时,单分散性好;共聚乳液的粒径随AA用量的增加而增加,粒径分布则随AA用量的增加而减小,乳液粘度随AA用量增大而降低,而粘接强度随AA用量增大而增加,耐水性下降。     

苯丙乳液的粒径与形貌控制研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和苯乙烯(St)为单体,采用半连续种子乳液聚合工艺,制备了苯丙聚合物乳液,研究了乳液聚合过程中的制备工艺、引发剂类型、乳化剂用量、种子乳液的乳化剂用量、预乳液和引发剂的滴加速率对不同阶段的乳胶粒粒径及其分布的影响。结果表明:半连续种子乳液聚合,单体滴加工艺制备的乳液粒径最小;引发剂种类对粒径无影响;乳化剂用量为10%时,乳液的粒径为96 nm,且分布宽度最窄,在种子乳液中乳化剂用量为40%时,乳液粒径最小,为104 nm;当预乳液滴加速度小于163 mg/s,引发剂滴加速率小于11.5 mg/s时,粒径未有变化。TEM测试表明了乳胶粒在整个乳液聚合过程中的成核长大的机理,并得到乳胶粒形貌可控的最佳方案。     

有机硅/丙烯酸酯乳液的粒径与分散行为研究

采用半连续乳液聚合法合成了以丙烯酸丁酯和甲基丙烯酸甲酯为成核单体,丙烯酸丁酯(MAA)、甲基丙烯酸甲酯(BA)、丙烯酸(AA)和γ―甲基丙烯酰氧基丙基三甲氧基硅烷为成壳单体的核壳结构乳液。采用马尔文纳米粒度仪等研究了乳液的粒径及其分布与引发剂和乳化剂用量之间的关系,粒径对乳液稳定性的影响以及乳液粒径与温度的关系,通过透射电镜对乳液微粒形态进行了分析。结果表明,乳液的粒径随着引发剂和乳化剂用量的增加而减小,乳液粒径在30～60℃时较为稳定,当引发剂过硫酸铵质量分数为0.55%,乳化剂十二烷基苯磺酸钠质量分数为2%时,制得的乳液粒径在120 nm左右,具有明显的核壳结构和较好的稳定性。     

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。     

用阴离子Gemini 9 B-6-9 B乳化剂合成苯乙烯-丙烯酸丁酯共聚物纳米乳液

以壬基酚、1,6-二溴己烷、氯磺酸为主要原料合成的阴离子Gemini磺酸盐表面活性剂9 B-6-9 B为乳化剂,苯乙烯(St)、丙烯酸丁酯(BA)为单体,合成了乳胶粒径小于100 nm且分布均匀的苯乙烯-丙烯酸丁酯共聚物纳米乳液,考察了聚合温度、乳化剂用量、引发剂用量、单体配比、单体含量对乳液的影响,探讨了乳胶粒子成核机理。结果表明,随着温度的升高,乳胶粒子的平均粒径减小,转化率与凝胶率增大;随着乳化剂或引发剂用量的增加,乳胶粒子的平均粒径和凝胶率减小,转化率增大;随着软单体比例的增加,乳胶粒子的平均粒径与转化率增大,粒径分布变宽,凝胶率减小;单体用量增大,乳胶粒子的平均粒径与凝胶率增大,转化率降低;乳胶粒子的粒径呈单峰分布,可能是按胶束成核机理形成的。     

阳离子聚合物乳液的合成及其在涂料染色中的应用

采用无皂乳液聚合的方法,选择合适的阳离子单体和引发剂,合成了稳定的阳离子型聚合物乳液.分析了软单体BA、硬单体St、阳离子单体DMC、引发荆APS用量和搅拌速度等因素对乳液粒径及稳定性的影响.结果表明,当阳离子单体、软、硬单体用量分别为13.14%、6.18%和2.32%,引发剂用量为0.5%,搅拌速度为250 r/min时,合成的乳液粒径为383.3 nm,具有较好的稳定性.应用于涂料染色织物,阳离子聚合物乳液具有比商品粘合剂高的干湿摩擦牢度.电子显微镜的观察结果说明,阳离子乳液能够在织物表面形成更完整均匀的聚合物薄膜.     

室温离子交联苯丙乳液合成及性能研究

以苯乙烯(St)、丙烯酸丁酯(BA)和丙烯酸(AA)为单体,过硫酸钾(KPS)为引发剂,采用乳液聚合方法通过离子交联合成了室温交联型苯丙乳液。考查了聚合温度、引发剂用量、乳化剂用量对聚合稳定性和乳液性能的影响,同时研究了Zn~(2+)/AA配比和软硬单体配比对胶膜性能的影响。结果显示,在80℃、KPS用量为0.4%、乳化剂用量为2.0%~3.5%时,乳液具有较好聚合稳定性以及粒径单分散性;随配比中醋酸锌用量增加,胶膜的干燥时间缩短,吸水性减小,而拉伸强度有适当提高;随体系中硬单体含量增加,胶膜的干燥时间增加,而硬度和拉伸强度则逐渐提高,吸水性变小。     

影响苯丙乳液黏度与粒径的因素分析

采用种子乳液聚合法,以苯乙烯、丙烯酸丁酯、丙烯酸异辛酯、甲基丙烯酸甲酯等为主要原料合成了用于制备胶粘剂的苯丙乳液。重点研究了引发剂、乳化剂及种子单体的用量及硬软单体不同配比对苯丙乳波黏度和粒径的影响。实验结果表明,当引发剂用量为0.5％（占单体总质量,后同）、乳化剂用量为1％、种子单体用量为8％、硬软单体配比为30／46的条件下,合成的笨丙乳液黏度较高、粒径小、粒度分布宽,用该乳液制备的胶粘剂具有优良的施工性能.     

苯乙烯/羟甲基丙烯酰胺无皂乳液共聚合的研究

以苯乙烯为主单体,N-羟甲基丙烯酰胺为功能性单体、K2S2O8为引发剂制备了固含量较高、稳定性较好的苯乙烯/N-羟甲基丙烯酰胺无皂共聚物乳液,探讨了固含量、单体配比、反应温度、引发剂用量等条件对乳液稳定性和粒径大小的影响。结果表明,合成最佳条件为固含量25%,功能性单体20%,引发剂1.7%,反应温度75℃。     

阳离子微乳液的合成

比较了阴、阳离子型引发剂以及各种不同阳离子型乳化剂和功能单体甲基丙烯酸二甲氨基乙酯用量对乳液合成转化率的影响.用激光粒度仪和电镜分析表征了乳液的粒径,研究了乳化剂用量对乳液粒径的影响.     

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.     

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。     

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.