硅溶胶/含氟聚丙烯酸酯复合乳液的制备与表征

采用经典的St(o)ber法在常温下制备纳米级硅溶胶,用3-(甲基丙烯酰氧)丙基三甲氧基硅烷对其改性.在阴离子乳化剂和非离子乳化剂共同存在下,通过乳液聚合制备了硅溶胶/含氟聚丙烯酸酯复合乳液.表征了乳胶粒形貌,测试了共聚物组成及性能、乳液稳定性和乳胶膜性能.结果表明:乳胶粒有明显的核壳结构,乳液有良好的储存稳定性、稀释稳定性、高温和低温稳定性;硅溶胶/含氟聚丙烯酸酯复合乳胶膜吸水率达12.50％,对水的接触角为93 5°;复合物的热稳定性高于普通聚丙烯酸酯共聚物和含氟聚丙烯酸酯共聚物.     

高固含量聚合物乳液研究新进展

将高固含量(>6O%)聚合物乳液的制备方法按机理分为控制乳胶粒直径分布、增大乳胶粒直径和使乳胶粒发生形变3类。综述了高固含量乳液的制备工艺和方法、基础理论及应用研究近况,并对高固含量乳液制备的发展进行了展望。     

具有核壳结构有机硅改性醋丙乳液的制备及其性能

采用半连续种子乳液聚合法,以聚合性乳化剂SVS制备核壳结构有机硅改性醋丙乳液,通过红外光谱和DSC表征乳胶粒化学组成和玻璃化温度。考察聚合性乳化剂SVS与有机硅单体用量对乳液聚合稳定性和制备乳液耐水性能的影响。DSC测试结果表明乳胶粒具有核壳结构;在SVS用量为2.5%（wt）,有机硅单体用量为3.0%（wt）时,乳液稳定性和乳胶膜的耐水性能较好。     

pH敏感的水溶性氨基聚合物的制备及其对乳液成膜的影响

从乳胶粒的成膜驱动力入手,研究了在乳液中加入pH敏感的水溶性氨基聚合物,利用特定条件下,氨基聚合物破坏乳胶粒的双电层,从而克服乳胶粒聚结的斥力,促使乳胶粒快速聚结成膜。探讨了不同条件下氨基聚合物的制备、氨基聚合物与乳液稳定共存的条件以及对乳液干燥速度的影响。     

不同粒径含氟丙烯酸酯共聚乳液的合成及膜表面疏水性能研究

采用半连续种子乳液聚合的方式,以丙烯酸丁酯、甲基丙烯酸甲酯和甲基丙烯酸六氟丁酯为原料制备了粒径分别为30nm、75nm、210nm左右的含氟丙烯酸酯共聚物乳液。通过乳胶粒核壳结构设计与大小粒径乳液机械共混改性2种方法研究了如何在较少含氟单体用量的情况下达到较好的表面疏水性能。利用X射线光电子能谱、动态光散射仪、接触角测定仪等分析手段,研究了共聚物膜的表面性能和共聚物乳液粒径的大小及分布,测试结果表明,核壳结构乳液成膜后壳层含氟量较高,膜表面接触角大于90,°疏水性能强;而大小粒径乳液共混物成膜后表面含氟量较低,却仍能得到90°以上的接触角,表明乳胶膜表面具有粗糙结构,具有一定的仿荷叶效应。     

自制反应性乳化剂制备的含氟核壳乳液及性能

采用烷基酚聚氧乙烯醚（OP-10）与顺丁烯二酸酐反应,制得反应性乳化剂;以甲基丙烯酸甲酯（MMA）和丙烯酸丁酯（BA）为核,甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸十二氟庚酯（DFMA）为壳,采用半连续种子乳液聚合方式制备核壳型含氟丙烯酸酯乳液。对反应性乳化剂的性能进行了初步探究,并通过红外光谱、TEM、DSC、CA、TGA等对体系进行了研究。结果表明,自制的反应性乳化剂性能优异,合成的乳胶粒具有典型的核壳结构,乳液性能稳定;反应性乳化剂的引入使涂层具有较低的表面能,有效地提高了乳胶膜的疏水性能。     

有机氟无机纳米二氧化钛复合改性丙烯酸酯乳液的制备及性能研究

采用半连续种子乳液法将自制的表面亲油性接枝改性纳米二氧化钛与含氟单体甲基丙烯酸十三氟辛酯(G06B)等复合改性丙烯酸酯乳液,用红外光谱(FT-IR)、乳胶膜表面形态分析(AFM)、热重(TG)和拉力机等测试手段研究了表面改性无机纳米TiO_2以及有机氟的引入对乳液及乳胶膜性能的影响。结果表明,改性TiO_2的引入显著增强了聚合物乳胶膜的力学性能并进一步优化了乳胶膜的表面疏水性;乳胶膜疏水性随含氟单体用量增加而增大,热稳定性也有一定地提高,当G06B用量为20%、改性TiO_2用量为0.2%时,乳胶膜的综合性能相对最佳。     

含氟丙烯酸酯核壳乳液的制备与性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主单体,分别加入丙烯酸六氟丁酯(HFBMA)和甲基丙烯酸十二氟庚酯(DFHM)作为聚丙烯酸酯改性剂,制备了2种含氟丙烯酸酯核壳乳液。采用1H-NMR、TEM、DSC、EDS-SEM、Zeta电位及纳米激光粒度仪等表征了乳胶粒子的组成、结构、粒径及其分布以及乳胶膜表面氟元素的含量。研究了2种含氟单体的用量对乳液稳定性、乳胶膜吸水率、单体转化率、乳胶膜表面疏水疏油性等的影响;研究结果表明:DFHM的改性效果明显好于HFBMA。当DFHM的加入量为4%时,乳胶膜对水的接触角达到93.5°,吸水率降为11.54%,对正己烷的接触角达到82.0°;乳胶粒子的平均粒径70.02 nm,粒径分布窄(PDI=0.082),且具有核壳结构;SEM-EDS测试结果显示,制备的含氟聚合物在成膜过程中,氟元素更易向表面迁移,从理论的5.70%上升到13.47%,从而使乳胶膜具有更好的疏水和疏油性能。     

微波辐射制备室温自交联含氟聚丙烯酸酯乳液

在微波辐射下,以甲基丙烯酸十二氟庚酯(DAAM)为含氟单体,双丙酮丙烯酰胺为功能单体,己二酸二酰肼为交联剂,阴离子十二烷基硫酸钠和非离子脂肪醇聚氧乙烯醚为复合乳化剂,在过硫酸钾的引发下,制备了可室温自交联的含氟聚丙烯酸酯乳液。考察了交联单体用量对转化率、粒径分布及分布指数和乳胶膜吸水率的影响。w(DAAM)为5%时,乳液乳胶粒呈球形,平均粒径在60~70 nm。随着DAAM用量的增加,乳胶膜吸水率减小,此时交联起主导作用;进一步增加DAAM用量,乳胶膜吸水率反而增大,此时亲水性起主导作用。     

可再分散乳胶粉的制备与性能表征

研究间歇法、平衡溶胀法和半连续法不同工艺制备乳液，并对不同工艺制备的乳液测试其性能．详细分析了乳液胶粒粒径的分布，不同胶粒粒径对乳液性能差异的影响。对制得的产品的性能进行了表征，用喷雾干燥法可以制得性能良好的可再分散乳胶粉。     

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。