硅油乳液的制备及乳化条件的研究

以1 000 mPa·s硅油为主要原料,研究了乳化剂HLB值与配方的选择及硅油乳液的制备中乳化方法、乳化时间、乳化温度和pH等乳化条件的选择,得到较佳工艺为w(复配乳化剂)=6%,采用剂在油中法,乳化温度70℃,乳化时间共40 min,乳化体系的pH保持在6左右.制备的硅油乳液固含量约为30%,乳液外观为均匀、细腻的乳白色黏性液体.     

影响乳化硅油颗粒度因素的考察

以二甲基硅油为主要原料,非离子表面活性剂复配制备乳化硅油,考察了乳化剂用量、乳化时间、乳化温度、pH、搅拌速度、乳化水温度和乳化方法等工艺条件对乳化硅油颗粒度的影响。结果表明,在50～90℃,乳化温度对乳液粒径影响不显著;乳化剂用量、乳化时间、pH、搅拌速度和乳化方法对乳液的粒径均有影响。w(乳化剂)=7%,乳化时间45min,乳化温度80℃,乳化体系的pH≈6,在1200r/min的搅拌速度下采用乳化剂在油中法,制得了平均粒径为1.561μm,折光率为1.403,表观黏度216mPa.s的固体份质量分数为30%的硅油乳液。应用文中所述的工艺条件,脱膜剂厂家制备出了性能优良的乳化硅油脱模剂产品。     

高稳定性硅油乳液的制备研究

以2 000 mPa.s的二甲基硅油为主要原料,研究了乳化剂配方的选择、硅油乳液制备的条件,考察了乳化剂用量、乳化时间、乳化温度和搅拌速度等因素。结果表明,最佳乳化条件为:乳化剂用量为7%,乳化温度70℃,乳化时间30 min,搅拌速度800 r/min,乳化水分2次加入,乳化时间分别为10 min和20 min。制备的固含量约为40%的硅油乳液,稳定性和分散性好。     

石蜡乳液的制备

以60#全精炼石蜡为原料,乳化剂的加入采用剂在油中加入法制备石蜡乳液;研究了乳化剂种类、乳化温度、乳化时间、去离子水用量、乳化剂的亲水亲油平衡值(HLB)、搅拌速度等因素对石蜡乳液稳定性的影响,结果表明:在乳化剂为TW-80/SP-80,乳化温度85℃、乳化时间30min、w(去离子水)=68%、搅拌速率1 000r/min、HLB=10.006 7的条件下制备出的样品有最佳的乳化效果。     

影响高固含量石蜡乳液颗粒度因素的考察

以58#石蜡为原料,非离子与阴离子表面活性剂复配物为乳化剂,考察了乳化剂的HLB(亲水亲油平衡)值、乳化剂用量、乳化温度、乳化时间、搅拌速度和乳化方法等工艺条件对石蜡乳液颗粒度的影响.结果表明,石蜡乳化剂适宜的HLB值约为9.3,乳化剂的用量、乳化温度、乳化时间、搅拌速度和乳化方法对乳液的粒度均有影响.w(乳化剂)=7%,乳化温度85℃～90℃,乳化时间40 min,搅拌速度为1 000 r/min下采用剂在油中法,制得了平均粒度为1.3 μm,折光率为1.42,固含量约为50%的石蜡乳液,乳液外观为均匀、细腻的乳白色液体.     

单组分乳化剂制备硅油乳液及影响因素研究

通常硅油乳液是在加热条件下,采用复配型乳化剂乳化硅油获得。而试验在常温条件下,以100mPa·s的二甲基硅油为原料,以单组分乳化剂成功制备出固含量约为60%的硅油乳液,并且所得乳液不必调节pH值,工艺实现简化。主要研究了硅油乳化工艺中乳化剂类型及用量、乳化方法、乳化水用量、搅拌速度、乳化时间等的选择。获得的最佳工艺条件:采用剂在油中法,异构醇醚系E型乳化剂用量为5%(质量百分含量),乳化水用量约40%,搅拌速度900r/min,乳化时间30min。在此条件下得到的硅油乳液外观均匀、细腻,具有良好的稳定性和分散性。     

甲基硅油乳液的制备研究

以二甲基硅油为原料,非离子型表面活性剂为乳化剂,制得甲基硅油乳液。研究了硅油用量、乳化剂用量、乳化体系HLB值、搅拌速度、剪切时间等对乳液性能的影响。较佳工艺为:黏度350 m Pa·s、1 000 m Pa·s的二甲基硅油按质量分数14%、10%,复合乳化剂用量为6%,乳化体系HLB值控制在10.3,搅拌速度800 r/min,乳化水分2次加入(除硅油和乳化剂外,其余为水,约占70%;水分两次加入,第一次加入直到转相时停止,继续分散一段时间后第二次加入),转相前加水剪切时间为30 min,转相点停止加水剪切搅拌10 min,制得固体质量分数为30%的具有良好分散性、稳定性的硅油乳液。     

硅油乳状液制备新工艺研究

以二甲基硅油(500 000 mm2/s)为原料,AEO3、AEO7、OP乳化剂组成复配乳化剂,用自主研发的搅拌器,成功在常温下制备出固含量约为56%的硅油乳液。考察了乳化剂选择、乳化方法、乳化剂用量、乳化时间等因素对硅油乳液性能的影响。结果表明,硅油乳化的最佳工艺条件是:采用剂在油中法,乳化剂用量为5%(相对于乳液总质量),乳化时间为80 m in。在此条件下,得到的硅油乳液外观均匀、细腻,具有良好的稳定性和分散性。所得乳液不必调节pH值,工艺实现简化。     

超高黏度聚二甲基硅氧烷大粒径乳液的制备

以异构十三碳聚氧乙烯醚5(1305)和油酸酰胺丙基甜菜碱(OAB)为乳化剂,采用转相乳化法将黏度100万CS的聚二甲基硅氧烷制成粒径29.76μm,黏度7 000 m Pa·s,固含量65%的大粒径乳液,并对助剂及其用量、乳化工艺等因素进行了研究。结果表明,助剂的最佳配方为:w(乳化剂)=2.77%(相对于聚二甲基硅氧烷),w(1305)∶w(OAB)=1∶1,瓜尔胶羟丙基三甲基氯化铵的用量为0.6%;最佳工艺条件为:乳化温度50~55℃,转相前搅拌速度70 r/min,转相后搅拌速度500 r/min,体系真空度0.035 MPa。     

具有良好稳定性的石蜡乳液的制备及改进

选用Span80、Tween80为石蜡复配乳化剂,采用O-D乳化法与PIT法相结合研究了乳化剂HLB值、乳化剂用量、乳化水加入方式及用量、乳化时间、乳化温度、搅拌方式及搅拌速度对石蜡乳液制备的影响。结果表明,适宜的乳化工艺条件为:复合乳化剂的HLB为10.5,复合乳化剂的用量(M乳化剂/M石蜡)为30%,乳化水用量(M水/M石蜡)为2.5,乳化时间30 min,乳化温度75℃,搅拌速度1 000 r/min。在该条件下可制得具有良好稳定性和分散性的石蜡乳液,粒径单分散性也较好。     

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。