悬浮法成型UP微粒粒径及其分布的控制

以不饱和聚酯树脂（UP）为原料,采用悬浮成型方法制备了粒径为120～250μm的UP球形微粒,从工艺控制的角度考察了搅拌速度、搅拌器形式及反应嚣形式对UP微粒平均粒径及粒径分布的影响。结果表明,将搅拌速度控制在500～1000r／min,以4口圆柱形烧瓶为反应器,采用双层平桨、且桨叶间距为4．5cm时,所制UP微粒的粒径最小、且粒径分布最窄。     

UPR/Al_2O_3复合微粒的密度及硬度研究

用不饱和聚酯(UPR)和Al2O3微细粉悬浮聚合法制备了UPR/Al2O3复合微粒,研究了两种粒径的Al2O3粉料在制备过程中对UPR/Al2O3复合微粒密度和硬度的影响.结果表明:悬浮聚合法能制备出圆整光滑的UPR/Al2O3复合微粒,且粒径在140～250 μm之间的收率达到60%～75%;Al2O3能有效地增加复合微粒的密度和硬度,当Al2O3用量相同时,超细级粒径粉料的Al2O3增密和增硬效果较纳米级粒径粉料好;Al2O3质量分数为55%时,用两种粉料增强的复合微粒的硬度分别达到最大值39.42 HV和25.66 HV.     

树脂封装半导体元件去毛刺喷射磨塑料研究

以悬浮聚合法制备出不饱和聚酯树脂(UP)/Al2O3复合微粒作为喷射磨塑料,对比了其与日本磨塑料的粒径、密度、硬度、热变形温度等性能指标及其在实际应用中的打磨能力、磨损率及破碎率等指标。结果表明,自制的喷射磨塑料粒子的粒径、密度和打磨能力与日本生产的磨塑料相当,而硬度、热变形温度、磨损率和破碎回收率均优于日本产品。     

响应曲面法优化水包油型天然松香乳液的制备

以天然马尾松松香为原料、ONIST APS-350为乳化剂采用常压转相法制备水包油（O/W）型天然松香乳液。考察了乳化剂用量、初始乳化温度、油水比（松香和水质量比,下同）与搅拌速度对O/W型天然松香乳液粒径分布的影响,并通过响应曲面法（RSM）对制备乳液的工艺参数进行模拟与优化。结果表明：制备O/W型天然松香乳液的最佳工艺条件为搅拌速度500 r/min、乳化剂用量9.95%、初始乳化温度112℃、油水比10：31,所得乳液平均粒径为131.1 nm,乳液离心稳定,静置3个月不分层,通过TEM表征发现,这种天然松香乳液颗粒具有核壳结构,其粒径大小与粒径仪测试结果一致。     

疏水作用色谱用球状交联聚乙烯醇的制备

采用悬浮聚合法成功地制备了PVA白球 ,对水溶液中PVA含量、甲醛用量、表面活性剂配伍和用量、油水体积比、搅拌速度及反应温度等影响因素进行了研究和探索。优惠工艺条件为 :5 0ml 15 %PVA分散在 3 0 0ml的油相中 ,以 3 .0 g油酸钠和 5 .0mlspan -80作表面活性剂 ,用 10ml甲醛溶液作交联剂 ,在 88℃和 40 0r/min的条件下进行悬浮聚合。制备得到了缩醛化度为 3 0 %的球状PVA颗粒 ,其中粒径为 0 2 4～ 0 .3 5mm的约占 80 %。     

漆酚缩甲醛聚合物微球的制备及其吸附性能

本文利用悬浮缩聚的方法合成漆酚缩甲醛聚合物微球,考察悬浮缩聚过程中单体的预分散、分散剂用量、单体的预聚、油水比例、催化剂用量、反应温度以及搅拌速度等对微球的形貌结构与性能的影响。结果表明,漆酚单体经预聚合后,在Mg(OH)2分散剂的作用下分散于甲醛水溶液中;在弱碱催化剂NH3·H2O的作用下,当油水比R=0.163时,搅拌速度r=300r/min时,于80℃～85℃进行悬浮缩聚反应,可以得到粒径为300μm,内部为多孔结构的聚合物微球。微球可以吸附废水中的重金属离子Cu2+、Pb2+和Cd2+等,其吸附选择性为Pb2+(21.9mg/g)Cu2+(21.3mg/g)Cd2+(7.1mg/g)。     

悬浮聚合法制备微球状压敏胶的研究

以丙烯酸-2-乙基己酯(2-EHA)、丙烯酸甲酯(MA)和丙烯酸(AA)为共聚单体,聚乙烯醇(PVA)为分散剂,过氧化苯甲酰(BPO)为引发剂,采用悬浮聚合法制备了可重复粘贴的微球状PSA(压敏胶).研究了水油比(即水与主单体质量比)、软硬单体质量比、分散剂种类和搅拌速率等对聚合物粒径及PSA性能的影响.结果表明:当水...     

球形木质素珠体的制备及其粒径分布研究

利用反相悬浮聚合技术制备球形木质素珠体,并采用正交实验综合研究了木质素珠体研制过程中各影响因素对珠体形成和粒径分布的影响。结果表明,以自制的复合分散剂L1, 采用体积比为1∶1的变压器油与氯苯混合物作为分散相,油水相比为3∶1,搅拌速度为200 r/min,反应温度80℃左右,反应体系的酸度控制在1.5 mol/L时,反应2 h后所得到的球形木质素珠体粒径分布最均匀,粒径在0.4~0.8 mm的木质素珠体占木质素珠体总质量的83.2%。     

悬浮聚合法制备彩色墨粉的研究

通过悬浮聚合法制备的彩色墨粉为球形、粒径小且分布均匀。研究了水油比、PVA用量和反应搅拌速度对墨粉粒径的影响,同时研究了影响彩色墨粉粒子荷电性能及热力学性能的因素,为悬浮聚合法制备的彩色墨粉的进一步研究奠定了基础。     

疏水作用色谱用球状交联聚乙烯醇的制备

采用悬浮聚合法成功地制备了PVA白球。本文对水溶液中PVA含量、甲醛用量、表面活性剂、油水体积比、搅拌速度及反应温度等影响因素进行了研究和探索。实验得到了最佳工艺条件为：50ml15％PVA分散在300ml的油相中,以3.0g油酸钠和5．0molSpan－80作表面活性剂,用10ml甲醛溶液作交联剂,在88℃和400r/min的条件下进行悬浮聚合,制备得到了缩醛化度为30％的球状PVA颗粒,其中粒径0．30－0．45mm（40－60目）者约占80％。     

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。