核/壳型含硅苯丙乳液的合成与研究

以甲基丙烯酸甲酯(MMA)和苯乙烯(St)为核单体,丙烯酸丁酯(BA)、丙烯酸(AA)和γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH-560)为壳单体,制备出具有核/壳型结构的含硅苯丙乳液。采用激光粒度分析法、差示扫描量热法(DSC)、红外光谱(FT-IR)法和透射电镜(TEM)等测试手段,研究了软硬单体配比、乳化剂、引发剂和交联剂KH-560用量对乳液及其胶膜性能的影响。研究结果表明,当w(引发剂)=0.5%、m(BA)∶m(St)∶m(MMA)=1.5∶0.5∶1.0、w(混合乳化剂)=3.0%和w(KH-560)=16%时,制取的含硅苯丙乳液稳定性好、平均粒径小且分布较窄,适度交联可提高乳胶膜的耐水性和硬度。     

高固含量苯丙微乳液的合成与表征

以过硫酸铵(APS)为引发剂,反应性乳化剂烷基酰胺乙烯磺酸钠(DNS-86)和辛基酚聚氧乙烯醚(OP-10)为复配型乳化剂,正戊醇(n-PTL)为助乳化剂,采用种子乳液聚合法制备苯乙烯(St)、丙烯酸甲酯(MA)、丙烯酸丁酯(BA)、丙烯酸(AA)的四元共聚微乳液。讨论了引发剂用量、乳化剂用量及配比、软硬单体配比等因素的影响。FT-IR和DSC测试结果表明,苯乙烯、丙烯酸酯类单体间发生了自由基共聚反应;TEM测得乳胶粒子平均粒径为35 nm。当m(BA)∶m(St MA)=4∶6,m(DNS-86)∶m(OP-10)∶m(n-PTL)=11∶3∶2,引发剂用量为单体质量的0.7%时,所得乳液性能优良,粒径在纳米范围内。     

核/壳型微乳液皮革填充黏合剂的合成及性能研究

以丙烯酸酯类单体为主要原料、以阴离子型乳化剂(F-20)和反应型非离子型乳化剂(X-03)为阴/非离子型复合乳化剂,采用预乳化半连续种子乳液聚合法合成了核/壳型丙烯酸酯微乳液。研究结果表明:当m(F-20)∶m(X-03)=3∶1、m(釜底乳化剂)∶m(预乳化液中乳化剂)=3∶1、m(核层中乳化剂)∶m(壳层中乳化剂)=1∶1、w(复合乳化剂)=9.0%、w(引发剂)=0.20%、固含量为25%和w(AA)=6%～8%时,相应核/壳型微乳液的综合性能良好,其平均粒径为29.1 nm,PDI(粒径分布指数)为0.223;将该乳液作为皮革填充黏合剂时,其填充性能优于单层微乳液,并且接近于国外同类产品。     

核壳型苯丙乳液的制备

采用预乳化工艺和种子乳液聚合技术合成了具有核壳结构的苯丙乳液,并讨论了引发剂、乳化剂、单体、反应温度、聚合工艺等对乳液合成的影响。最佳反应条件为:m(引发剂)∶m(总单体)=0.4∶100.0,m(乳化剂)∶m(总单体)=2.2∶100.0,m(苯乙烯)∶m(丙烯酸丁酯)=1∶1,反应温度控制在80～82℃。     

欠量加料核壳型乳液法合成核/壳型硅丙乳液的初步研究

采用欠量加料核壳型乳液合成法,以十二烷基磺酸钠和烷基酚聚氧乙烯基醚乳化剂为复合乳化剂,以丙烯酸甲酯和丙烯酸丁酯为核单体,以乙烯基三乙氧基硅烷和丙烯酸丁酯为壳单体,KPS为引发剂,制备出核预聚体和壳预聚体,又以乳化剂、水、p H缓冲剂、核预聚体制备出核种子乳液,然后通过半间歇法加入壳预聚体和壳引发剂制得核/壳型硅丙乳液。对乳液进行了红外光谱测定,并初步探讨了乳化剂的用量、乳液p H值、乳化温度、引发剂的用量等因素对合成过程中乳液稳定性的影响。结果表明,当乳化剂的用量为单体总量的5%,引发剂用量为单体的0.7%,乳化温度为75~80℃,p H在接近中性的6.5~8.0时,制得硅丙乳液稳定性最好。     

瓦楞纸浆内施胶用苯丙乳液的制备及应用

以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)为混合单体,十二烷基硫酸钠、烷基酚聚氧乙烯醚为复合乳化剂,过硫酸钾为引发剂,制备了苯丙乳液.结果表明,当m(St):m(MMA):m(BA):m(AA)=9∶26∶61∶4,复合乳化剂用量为单体总质量的3％,引发剂用量为单体总质量的0.6％时能够得到乳液粒径较小,稳定性较好的乳液.将制备的一系列乳液应用于瓦楞纸的抄纸试验,并讨论了苯丙乳液各影响因素对纸张性能的影响.     

高固含量核壳型丙烯酸酯乳液的制备与性能研究

以甲基丙烯酸甲酯为硬单体,丙烯酸丁酯(BA)为软单体,采用半连续种子乳液聚合方法合成了具有核壳结构的高固含量(不挥发物质量分数≥50%)丙烯酸酯乳液。采用红外光谱(FT-IR)、激光粒度仪(LPA)、透射电镜(TEM)等检测手段对产物进行了表征,同时考察了乳化剂的用量及复配比、引发剂、交联剂以及核单体中软单体含量对乳液性能的影响。结果表明:软﹑硬单体发生了共聚反应;乳液粒径分布较窄,核层聚合时适当加入少量BA,乳液的稳定性能明显提高,复合乳化剂m(SDS)∶m(OP-10)为2∶1且质量分数为3%,引发剂KPS质量分数为0.5%,交联剂EGDMA质量分数为2%时可制得性能较好的乳液。     

聚合条件对丙烯酸酯微乳液粒径及其分布的影响

以烯丙氧基壬基酚聚氧乙烯(10)醚硫酸铵(DNS-86)为阴离子型反应性乳化剂、过硫酸钾(KPS)为引发剂,制备丙烯酸酯微乳液。研究了聚合工艺、乳化剂、引发剂和单体等对微乳液的粒径及其分布的影响。结果表明:随着DNS-86、KPS用量的不断增加,乳胶粒的粒径逐渐减小,但过多加入KPS时会导致乳胶粒的粒径增大;乳胶粒的粒径均呈双峰分布,并且双峰随单体用量增加均向大粒径方向偏移;当w(DNS-86)=11%、w(KPS)=0.5%和m(单体)∶m(水)=6∶14时,采用种子预乳化半连续聚合法,可以制备出粒径小(平均粒径为39 nm)、分布窄(粒径分布指数为0.202)的丙烯酸酯微乳液。     

丙烯酰胺氧化-还原引发体系反相乳液聚合

以过硫酸钾和亚硫酸钠为引发剂,Span-80和OP-10为乳化剂,进行了丙烯酰胺的反相乳液聚合研究;对合成产物进行了FT-IR、线粒径分布测试和表征;探讨了反应温度、反应时间、引发剂用量、乳化剂用量以及油相与水相体积比对转化率的影响。研究结果表明,反应温度30℃,反应时间4 h,油水体积比4∶1,引发剂[n(过硫酸钾)∶n(亚硫酸钠)=1∶1]用量为单体质量的0.5%(质量分数),乳化剂[m(OP-10)∶m(Span-80)=1∶1]用量为单体质量的8.0%(质量分数),在此工艺条件下,单体转化率达98.8%,乳胶体积平均粒径112μm。     

乙烯基环四硅氧烷制备高硅含量硅丙乳液

以丙烯酸酯单体和四甲基四乙烯基环四硅氧烷(D4V1)为原料,采用种子乳液聚合法制备了以聚丙烯酸酯为核、聚丙烯酸酯-有机硅共聚物为壳的核-壳型高硅含量硅丙乳液.研究了引发剂、乳化剂、D4V1用量及反应温度对聚合反应的影响;并用IR、纳米粒度及Zeta电位分析仪对乳液及其乳胶膜进行表征.结果表明,最佳反应温度为75℃,引发剂、乳化剂(SDS与OP-10的质量比为1:1)的用量分别为单体总质量的0.3%、4%;在此条件下可制得有机硅质量分数达到20%以上(计算值)的硅丙乳液,且体系凝胶率低而单体的转化率较高,乳液的各项稳定性能较好,乳胶膜的吸水率小于20%.随聚合反应的进行,乳胶粒的粒径逐渐增大.     

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。