大分子乙烯基硅氧烷/丙烯酸酯单体核壳乳液聚合及表征

以甲基丙烯酸-2-羟乙酯(HEMA)和聚甲基氢硅氧烷(PMHS)为原料,合成了甲基丙烯酸乙氧基聚甲基氢硅氧烷醚(MEPMHSE)。以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主单体,加入合成的硅单体MEPMHSE作为聚丙烯酸酯改性剂进行核壳乳液共聚合,制得平均粒径为135.2 nm,粒径分布窄(PDI=0.045)的有机硅改性的具有核壳结构的聚丙烯酸酯乳液。采用FT-IR、1H NMR对MEPMHSE进行表征,并使用TEM、DSC以及Zeta电位及纳米激光粒径分析仪来表征乳胶粒子的结构与粒径。研究乳化剂的配比、含量以及MEPMHSE的加入量对乳液稳定性、吸水率、凝胶量以及乳液胶膜疏水性的影响。研究结果表明:用MEPMHSE改性的丙烯酸酯乳液胶膜的疏水性得到较大的提高,MEPMHSE添加量为6%时,所得丙烯酸酯乳液胶膜对水的接触角由空白对照样的65°提高到98°。     

有机硅改性丙烯酸酯乳液的制备及表征

以γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)、八甲基环四硅氧烷(D4)、丙烯酸酯类单体为原料,制备了有机硅改性丙烯酸酯乳液.考察了乳化剂配比、有机硅用量对乳液及乳胶膜性能的影响,并用红外光谱、凝胶渗透色谱、透射电镜进行了表征.结果表明KH-570先与低聚体D4开环预聚,再与丙烯酸酯类单体进行自由基聚合,可得到有机硅改性丙烯酸酯乳液;当有机硅占单体总质量的9%,其中m(KH-570)∶m(D4)=1∶9,m(MS-1)∶m(AEO)=2∶1时,乳液的黏度、凝胶率和乳胶膜的硬度随有机硅用量的增加而增大,乳胶膜的吸水率则降低;乳胶粒表面光滑均一,呈规则的圆球状,平均粒径为100 nm,其重均摩尔质量Mw=1.75×104g/mol,摩尔质量分布Mw/Mn=1.3.     

有机硅改性丙烯酸酯共聚乳液的合成及表征

采用间歇和种子半连续乳液聚合方法合成有机硅改性丙烯酸酯(硅丙)共聚乳液,用激光粒度仪、透射电子显微镜、差示扫描量热仪、表面张力仪等分析了硅丙共聚乳液和涂层的性能。采用种子半连续乳液聚合和间歇乳液聚合均可得到具有核-壳结构的硅丙共聚乳液。半连续乳液聚合得到的硅丙共聚乳液的粒径较小,粒径分布窄;采用半连续滴加纯丙烯酸酯单体和滴加单体预乳液对共聚乳胶粒子的平均粒径及粒径分布、形态影响不大。采用间歇乳液聚合可使有机硅单体的开环聚合和丙烯酸酯单体的自由基聚合同时进行,获得的硅丙乳液稳定性好,但聚合转化率偏低,乳胶粒子粒径较大,粒径分布较宽。硅丙共聚乳液胶膜的吸水率小于纯丙烯酸酯聚合物乳液胶膜,并随有机硅共聚率的增加而降低;硅丙乳液胶膜的接触角接近有机硅接触角。硅丙共聚乳液涂层整理的织物手感优异,但涂层牢度小于纯丙乳液整理剂。     

纳米硅溶胶改性聚硅氧烷微乳液的研究

采用乙烯基三乙氧基硅烷对纳米硅溶胶进行表面改性,使其表面接枝上可反应的乙烯基官能团,以过硫酸钾作为引发剂,与乙烯基有机硅单体、丙烯酸酯类单体进行原位聚合反应制备纳米硅溶胶改性聚硅氧烷微乳液。系统研究了聚合温度、乳化剂对聚合反应过程中乳液稳定性、乳胶膜吸水率以及乳胶粒子粒径的影响,结果表明:聚合过程中反应温度分别控制在80℃、90℃,转化率最高;烷基聚氧乙烯醚(AEO)与十二烷基苯磺酸钠(LAS)质量比为1.5∶1~2∶1,乳化剂用量为1.5%~2.0%时,制备的乳液稳定性最好,乳胶膜的吸水率低于3%,与其他共混乳液、聚硅氧烷乳液相比,吸水率显著降低;透射电子显微镜(TEM)观察结果显示:乳液中存在以纳米SiO2为核、聚硅氧烷聚合物为壳的结构形态,与共混乳液相比,改性乳液中游离的纳米SiO2粒子数大大减少。     

高固含量有机硅改性丙烯酸酯微胶乳的合成及性能

用自制的由阴离子乳化剂十二烷基硫酸钠(SDS)、非离子乳化剂辛基酚聚氧乙烯醚(OP-10)、反应型乳化剂WH-100以及非离子表面润湿剂所组成的混合乳化剂体系,通过半连续单体滴加法合成了平均粒径为59·8nm、粒径分布窄、总固物质量分数达40%的有机硅改性丙烯酸酯微胶乳,并对微胶乳及胶膜的性能进行了研究。结果表明,与间歇预乳化法制备的乳液相比,有机硅改性丙烯酸酯微胶乳的钙离子稳定性较差,其胶膜的吸水率较小,凝胶含量相当;随着乙烯基三乙氧基硅烷(A151)用量的增加,对转化率的影响不明显,微胶乳的钙离子稳定性、胶膜的吸水率下降,乳胶粒子的粒径变大,A151的质量分数宜为4%;随着功能单体甲基丙烯酸-2-羟乙酯(HEMA)用量的增加,微胶乳的钙离子稳定性先提高后降低,而胶膜的吸水率先降低后增大,HEMA的质量分数不宜超过3%。     

自交联型水基丙烯酸酯胶粘剂的合成与性能研究

以BA(丙烯酸丁酯)、MMA(甲基丙烯酸甲酯)、AA(丙烯酸)和HPA(丙烯酸羟丙酯)等作为主要单体,GMA(甲基丙烯酸缩水甘油酯)作为交联剂,采用半连续乳液聚合法制备了自交联型水基丙烯酸酯胶粘剂乳液,并将其应用于PVC(聚氯乙烯)/织物的粘接。研究结果表明:当m(软单体)∶m(硬单体)=5∶5、w(复合乳化剂)=3%⁴%、w(引发剂)=1.0%和w(GMA)=4%(均相对于总单体质量而言)时,胶粘剂乳液的综合性能相对最好,其平均粒径为126.8 nm、乳液稳定性良好、胶膜吸水率(4.23%)相对较低、耐热性相对较好且PVC/织物的剥离强度(28.3 N/25 mm)相对最大。     

含氟丙烯酸酯改性水性硝化纤维乳液的制备及其性能

以硝化纤维(NC)、异佛尔酮二异氰酸酯(IPDI)、丙烯酸(AA)、丙烯酸羟乙酯(HEMA)、全氟辛基乙基丙烯酸酯(FA)、三乙胺(TEA)为主要原料,采用自乳化法制备含氟丙烯酸酯改性水性硝化纤维乳液(WNC)。通过傅里叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、纳米粒度仪、动态流变仪以及视频光学接触角测定仪对所制乳液及薄膜进行了结构和性能表征,并考察了单体聚合温度、n(AA)∶n(HEMA)、含氟丙烯酸酯质量分数(占反应物AA、HEMA、NC、IPDI总质量的百分数)对乳液及其薄膜性能的影响。结果表明,所得WNC乳液性能稳定,乳液胶粒呈球形,具有核-壳结构。当单体聚合温度为60℃,n(AA)∶n(HEMA)=3∶1,含氟丙烯酸酯用量为1.0%时,所得乳液粒径较小且分布窄,平均粒径和分散系数分别是54 nm和0.023;改性后的乳液薄膜吸水率降低至2.0%,薄膜接触角增加至120°,相比较未改性的WNC乳液,改性后的WNC乳液薄膜具有优异的耐水性。     

有机硅改性丙烯酸乳液性能的研究

采用含乙烯基官能团的有机硅单体与甲基丙烯酸酯、丙烯酸酯和丙烯酸羟基酯等单体通过种子乳液聚合方法进行共聚,合成了有机硅改性丙烯酸酯共聚乳液,考察了有机硅单体用量对乳液机械稳定性、热稳定性、电解质稳定性和冻融稳定性的影响,同时还考察了乳液胶膜的机械性能和吸水率改进。     

有机硅改性聚丙烯酸酯细乳液的制备

以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)作为丙烯酸酯类单体,甲基三甲氧基硅烷(MTMS)和少量3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MEMO)作为功能性有机硅单体,采用细乳液聚合法,制备有机硅改性聚丙烯酸酯细乳液,考察了水解乳化工艺、有机硅单体含量、引发剂用量、乳化剂配比、稳定剂种类与用量以及单体与水质量比等对细乳液稳定性、粒径大小及分布的影响。结果表明,有机硅单体的总质量分数为30%,引发剂质量分数为1%,SDS与OP-10的质量比为3:2,单体和水的质量比为7:13的条件下,制备了高硅含量且稳定的有机硅改性聚丙烯酸酯细乳液,其凝聚率低至0.81%,粒径低至76 nm,粒径分布只有0.12,放置30 d以上仍稳定。     

软硬单体对聚硅氧烷/丙烯酸酯复合乳液的影响

以阳离子开环法制得不饱和PSiO(聚硅氧烷乳液)为种子,采用乳液聚合法与BA(丙烯酸丁酯)、MMA(甲基丙烯酸甲酯)、HPA(丙烯酸羟丙酯)、EO9TMPTA(乙氧基化三羟甲基丙烷三丙烯酸酯)共聚合成了一系列PSiOA(聚硅氧烷/丙烯酸酯)复合乳液。通过FT-IR、TEM、乳液稳定性、粒径、流变、胶膜吸水率、力学性能和热性能测试研究了BA/MMA质量比对复合乳液结构与性能的影响。研究结果表明:所制备的乳液粒径约为40～50 nm,随着BA/MMA比值的减小,乳液凝聚率、黏度增大,胶膜的热稳定性、耐水性、玻璃化转变温度(Tg)等综合性能得到了较大的提高;当m(BA)∶m(MMA)=1.8∶1.2时,综合性能最佳,拉伸强度为5.62 MPa,断裂伸长率为653%。     

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.