二甲基二氯硅烷水解反应探讨

以二甲基二氯硅烷、浓盐酸为原料合成二甲基二氯硅烷水解物,探讨了反应压力、停留时间、反应温度对二甲基二氯硅烷水解物黏度的影响,并在传统环路浓酸水解工艺基础上,增加氯化氢脱除装置(包括氯化氢脱除塔和水解物脱析罐)进行技术改进。结果表明：二甲基二氯硅烷水解反应的较佳条件为反应压力0.16～0.18 MPa、停留时间10～15 min、反应温度55℃;新增氯化氢脱除塔和水解物脱析罐后,水解物产品中的氯离子质量分数降至0.7×10^-6以下。     

反应物料对微型固定床反应器合成二甲基二氯硅烷的影响

利用微型固定床反应器,研究了直接法合成二甲基二氯硅烷的反应过程中硅粉质量、硅粉粒径及一氯甲烷流量对二甲基二氯硅烷的影响。结果表明,硅粉中杂质含量升高,反应出口气体中二甲基二氯硅烷的含量随之降低,硅粉中的Fe含量是影响二甲基二氯硅烷的主要因素;较小的硅粉粒径有助于反应初期缩短诱导期,但随反应的进行,硅粉的转化率和二甲基二氯硅烷的含量会下降;增加一氯甲烷流量,反应诱导期增长,硅粉转化率和二甲基二氯硅烷的含量均减小,但较小的流量在反应后期会出现二甲基二氯硅烷的含量严重下降的现象。     

微型固定床反应器合成甲基氯硅烷工艺条件的研究

利用微型固定床反应器研究了直接法合成甲基氯硅烷过程中温度、压力对二甲基二氯硅烷的收率和硅粉转化率的影响。结果发现:升高反应温度、增加反应压力可以缩短诱导期,增大反应速率,硅粉转化率和二甲基二氯硅烷收率也得到提高,但过高的温度和压力会使二甲基二氯硅烷的选择性下降。此反应体系的较佳温度为320℃,压力为0.4 MPa。     

助剂对二甲基二氯硅烷Wurtz聚合反应的影响

以二甲基二氯硅烷为反应单体、甲苯为溶剂 ,在超声波下 ,通过Wurtz法合成了聚硅烷。研究了助剂种类对该聚合反应的影响。结果表明 ,在甲苯溶剂中加入冠醚、二乙二醇二甲醚、六甲基磷酰三胺、聚醚等助剂可使该聚合反应在 80℃的较低温度下快速进行 ,从而降低了该聚合反应的危险性 ;冠醚、二乙二醇二甲醚、聚醚、六甲基磷酰三胺等对该聚合反应的促进作用 ,证明该反应活性中间体是阴离子活性体 ,该反应机理更倾向于阴离子聚合 ;冠醚的加入可极大地加快二甲基二氯硅烷的聚合反应 ;二甲基二氯硅烷加入后 ,反应立即进行 ,并放出大量的热 ,可根据反应温度的变化控制单体的滴加速率 ,防止爆聚现象出现 ,为大规模合成陶瓷先驱体聚硅烷提供了有利的依据     

阻燃剂聚二甲基硅酸对苯二酯的合成及应用研究

以二甲基二氯硅烷和对苯二酚为原料,合成聚合型有机硅阻燃剂聚二甲基硅酸对苯二酯。探讨了反应时间、反应温度对产率的影响,最佳工艺条件为:二甲基二氯硅烷和对苯二酚摩尔比为1∶1,在40℃下,将二甲基二氯硅烷滴入到对苯二酚中,于70℃反应7 h,纯化处理后,得到聚二甲基硅酸对苯二酯,产率为96.7%。通过FTIR、1HNMR、TG-DTA、极限氧指数表征产物的结构及性能。结果表明,该有机硅阻燃剂用于PBT、PP有较好的成炭阻燃效果,并与APP复配有很好的协同效应。     

浓酸水解法制备硅氧烷工艺条件探索

通过实验研究了二甲基二氯硅烷浓酸水解过程中盐酸浓度、反应温度、时间、原料配比对反应的影响,并对产物硅氧烷的水洗过程进行了研究,为开发二甲基二氯硅烷浓酸水解的新工艺提供了基础数据。结果表明,针对二甲基二氯硅烷浓酸水解过程,反应时间不应超过15 min,反应温度控制在35℃左右,原料二甲基二氯硅烷与浓盐酸的体积比为1∶12~1∶17。水洗过程中,碱液为6%的Na2CO3溶液,碱洗后再进行两次水洗,水洗温度为80℃以上,水洗过程中水相与有机相的体积比为5∶1,最终产物硅氧烷中氯离子含量为6.5 mg/kg,透明度为93%。在保证产品质量的前提下,浓酸水解在工艺和节能方面更具有优越性。     

阻燃剂聚二甲基硅酸对苯二酯的合成及应用

以二甲基二氯硅烷和对苯二酚为原料,合成聚合型有机硅阻燃剂聚二甲基硅酸对苯二酯。探讨了反应时间、反应温度对产率的影响,最佳工艺条件为:二甲基二氯硅烷和对苯二酚摩尔比为1∶1,在40℃下,将二甲基二氯硅烷滴入到对苯二酚中,于70℃反应7 h,纯化处理后,得到聚二甲基硅酸对苯二酯,产率为96.7%。通过FTIR、1HNMR、TG-DTA、极限氧指数表征产物的结构及性能。结果表明,该有机硅阻燃剂用于PBT、PP有较好的成炭阻燃效果,并与APP复配有很好的协同效应。     

单体合成中影响甲基氯硅烷产品质量的因素分析

分析了甲基氯硅烷合成反应中硅粉、氯甲烷、催化剂及助剂、温度、压力等因素对二甲基二氯硅烷质量的影响,给出了提高二甲基二氯硅烷产品质量一些建议。     

二(p-氨基苯氧基)二甲基硅烷的合成

通过二甲基二氯硅烷与对氨基苯酚的反应合成了1种新型氨基硅氧烷,采用核磁共振光谱,红外光谱及质谱对产物结构进行了表征并研究了溶剂?温度?原料配比以及反应时间等对合成产物的影响。结果表明,最佳合成反应条件为:对氨基苯酚与二甲基二氯硅烷的物质的量比为1.85∶1,苯作溶剂,反应温度70℃,反应时间7.5 h,产物收率可达61.5%。     

固载AlCl3催化剂在再分配法制备二甲基二氯硅烷中的应用

针对有机硅单体二甲基二氯硅烷生产中的副产物———甲基三氯硅烷和三甲基氯硅烷,采用自制的几种固载A lC l3催化剂,进行它们间的再分配反应,制得二甲基二氯硅烷,评价了各催化剂的性能,并采用L16(45)正交实验考察了反应温度、反应时间、催化剂加入量、反应物配比等因素对产物收率的影响。结果表明,反应温度与催化剂加入量对产物收率具有显著影响,实验确定了最佳工艺条件,二甲基二氯硅烷平均收率可达60.6%。     

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。