氰酸钾合成工艺条件的优化

以工业碳酸钾和尿素为原料 ,选用溶剂MSO合成氰酸钾 ,通过正交试验优化了工艺条件 ,最佳工艺条件为 :反应温度 1 4 0℃ ,反应时间 4h ,原料配比 2 .5∶1 ,溶剂配比 6 .0∶1 ,搅拌桨转速 390r/min ,所得氰酸钾质量分数 96 .32 % ,收率 88.4 4 %。采用红外光谱分析确证了其结构     

氰酸钾合成研究

以工业碳酸钾和尿素为原料,采用适宜的溶剂合成氰酸钾：通过正交试验优化了工艺条件,最佳工艺条件为,反应温度160℃、反应时间2.5h、原料配比2.5：1、溶剂配比8.0：1和搅拌浆转速280r／min,所得氰酸钾含量98.39％,收率84.17％。采用红外光谱分析确证了其结构。     

N-氨甲酰谷氨酸合成研究

以谷氨酸、氰酸钾为原料,脲丙酸为催化剂,经过亲核加成反应,重结晶纯化得到目标化合物N-氨甲酰谷氨酸。考察了物料配比、反应时间及温度对反应收率和产品稳定性的影响。优化反应条件为:n(谷氨酸)∶n(氰酸钾)=1∶1.2,反应温度控制在60~65℃,盐酸浓度为12 mol/L,此条件下产品的总收率达到87.0%,含量≥92.0%,产品结构经过1H NMR确认。     

联二脲绿色合成工艺研究

以盐酸氨基脲和氰酸钠为原料,水为溶剂,室温下合成了联二脲(HDCA)。采用红外和核磁表征确认了联二脲结构,考察了反应物配比、加料顺序、 pH值、反应时间和温度等因素对产品收率的影响。结果表明:原料配比n(盐酸氨基脲)∶n(氰酸钠)=1.0∶1.5,先加氨基脲,后分批加氰酸钠,水30 mL,室温反应30 min的条件下,产品收率为95.6%。     

Agglomeration and demulsification of emulsions by ultrasound

以水为连续相、二氯乙烷为分散相,配制成稳定的乳状液,在超声驻波场条件下,对其进行凝聚破乳研究,重点考察超声声强、超声辐照时间、沉降时间、超声作用频率对乳状液破乳的影响。结果表明,超声声强的改变直接影响了乳状液分散相液滴的凝聚和发散,超声破乳的声强应在临界阈值以下;超声辐照时间存在一个最佳作用时间;超声频率对液滴凝聚有重要影响,根据体系黏度、密度、液滴粒径等性质计算了最佳超声凝聚频率,并通过了实验验证。设计了正交实验,综合考虑了能耗和破乳效率,得到该乳状液破乳最佳条件为：超声频率10 kHz、声强270 W•m^-2、辐照时间9 min、沉降温度40℃及沉降时间3 h。此条件下,其破乳率可达到91%。     

乳状液超声凝聚破乳

以水为连续相、二氯乙烷为分散相,配制成稳定的乳状液,在超声驻波场条件下,对其进行凝聚破乳研究,重点考察超声声强、超声辐照时间、沉降时间、超声作用频率对乳状液破乳的影响。结果表明,超声声强的改变直接影响了乳状液分散相液滴的凝聚和发散,超声破乳的声强应在临界阈值以下;超声辐照时间存在一个最佳作用时间;超声频率对液滴凝聚有重要影响,根据体系黏度、密度、液滴粒径等性质计算了最佳超声凝聚频率,并通过了实验验证。设计了正交实验,综合考虑了能耗和破乳效率,得到该乳状液破乳最佳条件为：超声频率10 kHz、声强270 W•m^-2、辐照时间9 min、沉降温度40℃及沉降时间3 h。此条件下,其破乳率可达到91%。     

含异氰酸酯基丙基三乙氧基硅烷的合成

研究了氯丙基三乙氧基硅烷与氰酸钾反应制备异氰酸酯基丙基三乙氧硅烷的方法,考察了反应温度,反应物的配比优化,溶剂种类以及保护试剂的种类对合成产率的影响,确立了最佳的合成条件：反应物氯丙基三乙氧基硅烷与氰酸钾的摩尔比为1：1．15,DMF为溶剂,己内酰胺为保护试剂,反应温度为125℃,收率可达92％,并采用波谱分析确证了目标物质的结构。     

二甲酸钾的绿色合成

用甲酸和氢氧化钾为原料,不添加任何溶剂及催化剂进行一步合成得到二甲酸钾。首先通过单因素实验,对原料配比、反应温度和反应时间对反应收率的影响进行了一系列研究,从而初步确定了各工艺参数的适宜范围。以原料配比、反应时间和反应温度为考察对象,进行正交试验。通过正交试验获得最佳工艺条件:n (HCOOH)/n (KOH)=2.2、反应时间30 min、反应温度70℃,二甲酸钾产品收率为98%以上。测定产品熔点为106～109℃。     

软钾镁矾在乙醇-水和甲醇-水混合溶剂中的结晶特性

采用湿渣法系统地测定了软钾镁矾在乙醇-水和甲醇-水混合溶剂中的相平衡数据,利用电导率法确定了其在水中的超溶解度及结晶介稳区,考察了温度、搅拌速率和降温速率对介稳区的影响. 结果表明,35℃下,软钾镁矾在两混合溶剂中的溶解度随其中乙醇和甲醇比例增大而减小,当乙醇:水或甲醇:水为1:1(j)时,软钾镁矾溶解度接近0,且相同配比的混合溶剂中,甲醇-水溶液中K2SO4的结晶区比乙醇-水溶液中大;在实验范围内,软钾镁矾的介稳区宽度随降温速率由15℃/h增至35℃/h而由0.40%增至1.48%(w,以软钾镁矾计,下同),随搅拌速率由250 r/min增至460 r/min而由1.54%降至1.04%,随温度由25℃升至35℃而由1.61%降至1.24%.     

微波辅助下N-苯基吗啉的合成工艺研究

研究了苯胺与二甘醇二甲磺酸酯在微波辅助下合成N-苯基吗啉的新方法,采用单因素实验及正交实验法考察了溶剂、缚酸剂、原料配比、反应温度、辐照时间、微波功率等对反应收率的影响,获得了最佳工艺条件:以水做溶剂,碳酸钾做缚酸剂,原料配比:n(苯胺):n(二甘醇二甲磺酸酯):n(碳酸钾)=1:1.3:1.3,反应温度100℃,辐照...     

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。