戊二酸单薄荷酯合成工艺的研究

薄荷醇和戊二酸酐在催化剂4-二甲氨基吡啶(DMAP)的作用下,以甲苯为溶剂,合成新型清凉剂戊二酸单薄荷酯。采用单因素法优化了合成条件,得到较佳反应条件为:戊二酸酐和薄荷醇的物质的量比为1.5∶1,催化剂用量为薄荷醇的10%(物质的量分数),回流温度下反应10 h,收率在80%以上。     

尼龙酸二丁酯的合成

尼龙酸在固体酸催化下,与丁醇直接酯化、减压蒸馏制得合格的尼龙酸二丁酯。研究催化剂用量、原料水分和配比、反应温度和时间及蒸馏压力等因素对其制备产品的影响。其最佳工艺条件为:①酯化反应:催化剂用量为反应物总质量的1.0%～1.5%,n(丁醇)∶n(尼龙酸)=2.2∶1.0,在搅拌下,反应温度控制在145～155℃,反应时间9～10h;②减压蒸馏:蒸馏压力≤5.0kPa。     

苹果酸二薄荷酯的制备及其热裂解性质

以薄荷醇和苹果酸为原料,对甲苯磺酸为催化剂,采用熔融酯化法制备苹果酸二薄荷酯。优化的反应条件为:催化剂用量w(对甲苯磺酸)=1 5%,原料配比n(薄荷醇)/n(苹果酸)=2 4,反应时间5h,反应温度120℃,苹果酸二薄荷酯收率达61 5%。产物经IR、MS和1HNMR进行了结构表征,并在300、600和900℃对其热裂解性质进行了研究。     

固体酸催化合成尼龙酸二正丁酯

以尼龙酸和正丁醇为原料,固体酸SO₄^2-/ZrO₂做催化剂,催化合成尼龙酸二正丁酯。通过实验确定较为合适的反应条件：催化剂用量为尼龙酸质量的6%,醇酸摩尔比为3,回流反应时间5 h,催化剂可反复使用。此工艺条件下得到的尼龙酸二正丁酯收率达到97.2%,酯含量大于99%。     

丁香酸薄荷酯的合成与热稳定性研究

以丁香酸为原料,三乙胺为缚酸剂,酰化得到3,5-二甲氧基-4-乙酰基苯甲酸,再和L-薄荷醇在N,N′-二环己基碳酰亚胺/4-二甲氨基吡啶(DCC/DMAP)体系下,酯化反应得到3,5-二甲氧基-4-乙酰基苯甲酸薄荷酯,最后通过Bouveault-Blanc反应还原得到具有水果香气的香料丁香酸薄荷酯,总收率为62.2%(以丁香酸计)。利用核磁共振光谱(NMR)、气相色谱-质谱联用(GC-MS)、红外光谱(IR)和紫外光谱(UV)对3,5-二甲氧基-4-乙酰基苯甲酸薄荷酯和丁香酸薄荷酯进行结构表征。通过热重-微商热重-示差扫描量热(TG-DTGDSC)分析表明丁香酸薄荷酯是一种热稳定性较强的物质。     

3-吡咯甲酸乙酯衍生物的制备及其热裂解产物研究

以D-(+)-氨基葡萄糖盐酸盐为原料,通过环合、氧化和烷基化等系列反应,合成了新型化合物N-异丙基-2-甲基-5-甲酰基-3-吡咯甲酸乙酯,其分子式为C12H17NO3。此化合物的结构经1H NMR、13C NMR、IR和HR-MS等波谱技术进行确证,通过热重-微分热重-差示扫描量热(TG-DTG-DSC)研究了该化合物的热失重变化,并采用热裂解/气相色谱-质谱(Py/GC-MS)分析了该化合物的热裂解产物。研究显示,该化合物共经历两次失重过程。第一次失重在30℃至108.4℃之间,失重率为0.90%;第二次失重在108.4℃至280.0℃之间,失重率达到98.58%,在175.0℃时失重率最大。300、600和900℃下共裂解出54种化合物,其中含有吡嗪、己醛、环己酮、2,5-二甲基吡嗪、2,5-二甲基吡咯和苯甲醛等多种香味成分。300℃时,乙酸的相对含量最高,600和900℃时,2-甲基吡咯的相对含量最高。根据主要裂解产物,初步探讨了该化合物可能的热裂解机理。     

尼龙酸二乙酯的研制

以浓硫酸为催化剂,合成了尼龙酸二乙酯,讨论了反应物配比、催化剂用量、带水剂的用量及反应时间对酯产率的影响。     

一种吡嗪酯类香料前体的制备及其热性能

为开发吡嗪酯类香料前体,以2,5-二甲基吡嗪氮氧和丙烯酸噻吩甲酯为原料,在醋酸钯催化下经偶联反应,合成3-(3,6-二甲基-吡嗪氮氧-2-基)丙烯酸噻吩甲酯。通过~1HNMR、~(13)CNMR、IR、HRMS表征目标化合物的结构,并采用热重-微分热重(TG-DTG)和热裂解-气相色谱/质谱法(Py-GC/MS)测其热性能。结果表明,目标化合物从170℃开始降解,主要热失重区间为170～875℃,在257℃失重速率最大,总失重为76.5%。在300～900℃的有氧和无氧裂解氛围下,共鉴定出11种挥发性产物,主要有烷基吡嗪类、2-甲基噻吩、2-噻吩甲醇等特征香味物质。有氧氛围下热裂解产物种类较多,相对含量较高。依据主要裂解产物的种类及相对含量的变化,初步揭示了裂解机理。目标化合物在单料烟中的最适宜添加量为2 mg/kg。     

不同催化体系下L-丙交酯的合成及表征研究

以乳酸为单体,采用先缩聚后解聚的方法制备了L-丙交酯。首先通过正交实验较系统的研究了合成工艺,包括三种不同催化剂(锌粉、乙酸铜及辛酸亚锡)用量、脱水温度及裂解温度对产物收率的影响；进而考察了提纯方法对丙交酯最终产率及杂质(乳酸、水)含量的影响,并利用红外、热分析及核磁共振技术对产物结构进行了详细表征。结果表明,在辛酸亚锡催化下,脱水及裂解温度分别为130℃及190℃时,L-丙交酯单体的产率达到80%；通过多次重结晶可以得到较高纯度产物。     

本体聚合法制备低分子量水基钻井液降粘剂

采用本体聚合的方法,以苯乙烯(St)和马来酸酐(MA)为原料制备苯乙烯-马来酸酐聚合物(SMA),采用氯磺酸进一步磺化后得到低分子量的水基钻井液降粘剂磺化苯乙烯-马来酸酐(SSMA)。研究了单体配比、聚合温度、引发剂用量以及链转移剂用量对产物降粘性能的影响。结果表明,SMA的最佳合成条件为:在St与MA的摩尔比为1∶1的条件下,聚合温度为65℃,引发剂的用量为单体总质量的1.5%,链转移剂的用量为单体总质量的4%,经磺化改性制得的SSMA降粘剂能显著降低钻井液的粘度。利用红外光谱仪、凝胶色谱仪和差热分析仪对聚合物进行表征,可知所合成的聚合物结构与设计结构基本一致,重均分子量在3 000⁵ 000之间,分子量较低;通过热重分析曲线可知,在289℃左右失重保持在90%以上,聚合物热稳定性能良好。     

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。