高碘酸氧化法制备端氨基聚乙二醇的研究

单甲氧基聚乙二醇5000(m PEG5000)和对甲苯磺酰氯(p-Ts Cl)磺酸酯化,得到单甲氧基聚乙二醇对甲苯磺酸酯(m PEG5000-OTs),与乙醇胺亲核取代反应,获得末端具有β-氨基醇结构的聚乙二醇中间体,用高碘酸盐氧化,得相对分子质量5000的端氨基聚乙二醇(m PEG5000-NH2),总收率75.1%,产物结构通过IR和1H NMR进行表征。     

聚乙二醇单甲醚羧基衍生物的制备

以相对分子质量(简称分子量,下同)为1 200、2 000、5 000的聚乙二醇单甲醚(mPEG)为原料,采用琼斯试剂氧化法室温下制备羧基化的聚乙二醇单甲醚。产物结构经1HNMR和IR进行了确证。以羧基转化率为指标,探讨了反应物料最佳摩尔比为:n(Cr2O3)∶n(聚乙二醇单甲醚羟基)=2∶1,3种分子量产物的羧基转化率分别为99.6%,99.4%,98.0%。采用固液萃取法进行后处理,以产物外观颜色为指标,结果表明,固液萃取法中,先蒸除丙酮再加入碳酸氢钠中和的处理顺序获得的产物的颜色为白色,产物纯度高。以产物产率为指标,以分子量为1 000,1 200,2 000,5 000的聚乙二醇单甲醚(mPEG)及分子量为800的聚乙二醇(PEG)为原料制备羧基化衍生物,结果表明,该法适合于分子量大于2 000的聚乙二醇及分子量大于1 000的聚乙二醇单甲醚的羧基衍生物的制备,5种分子量产物的产率分别为88.2%,93.5%,98.0%,98.2%,39.1%。     

聚乙二醇单甲醚对甲苯磺酸酯的制备

以相对分子量2 000的聚乙二醇单甲醚(mPEG)与对甲苯磺酰氯(TsCl)为原料,再以三乙胺(TEA)为缚酸剂,进行亲核取代反应制备聚乙二醇单甲醚对甲苯磺酸酯(mPEG-OTs)。运用元素分析检测羟基转化率以及评价反应结果,通过单因素和正交实验来确定不同条件对羟基转化率的影响。结果表明,制备mPEG-OTs最佳工艺为:反应时间12 h,n(mPEG)∶n(TsCl)∶n(TEA)=1∶5.5∶5.5,反应温度为25℃。并通过IR与~1H NMR确定目标产物。     

聚乙二醇单甲醚对甲苯磺酸酯的制备

以相对分子量2 000的聚乙二醇单甲醚(mPEG)与对甲苯磺酰氯(TsCl)为原料,再以三乙胺(TEA)为缚酸剂,进行亲核取代反应制备聚乙二醇单甲醚对甲苯磺酸酯(mPEG-OTs)。运用元素分析检测羟基转化率以及评价反应结果,通过单因素和正交实验来确定不同条件对羟基转化率的影响。结果表明,制备mPEG-OTs最佳工艺为:反应时间12 h,n(mPEG)∶n(TsCl)∶n(TEA)=1∶5.5∶5.5,反应温度为25℃。并通过IR与¹H NMR确定目标产物。     

含5-氟尿嘧啶的聚乙二醇酯的制备与表征

采用氯乙酸与不同分子量的聚乙二醇进行酯化反应得到氯乙酸聚乙二醇酯,由于酯中的α-氯具有良好的反应活性,将它再与抗癌药物5-氟尿嘧啶结合制备了不同分子量的高分子前药,并对得到的产物进行表征。产物的体外降解实验表明,该产物具有长效缓释的功效,其中(PEG 2000)-5-FU的载药量为18.6%,随着聚乙二醇分子量的增加,产物水溶性提高,当聚乙二醇相对分子质量为2000时水解速率最大。     

不同分子量聚乙二醇单修饰重组人干扰素a-2a

利用N-羟基琥珀酰亚胺活化制备不同分子量的聚乙二醇修饰剂(NHS-mPEG，分子量5000, 10000, 20000)，考察三者水解动力学性质的差异，结合正交实验确定了不同分子量修饰剂制备单条PEG链修饰重组人干扰素a-2a(rhIFN-a-2a)的最佳反应条件，用离子交换法对产物进行分离纯化. 研究了不同分子量聚乙二醇干扰素结合物的体外活性，比较其蛋白收率. 实验结果表明，修饰剂分子量增大，应选择蛋白与修饰剂的反应活性高的修饰反应条件，体外活性虽然降低，但同时单修饰聚乙二醇干扰素结合物收率更高，产品质量更易控制.     

聚乙二醇对碳酸化法白炭黑的表面改性研究

以石灰窑气和水玻璃碳酸化法制备白炭黑为研究体系,用表面活性剂聚乙二醇(PEG)原位有机湿法改性,以提高白炭黑同聚合物胶料的亲和性。在85℃,原料配比(水玻璃与水体积比)1∶5,二氧化碳浓度40%,通气速率60 mL/min和搅拌速率180 r/min的实验条件下反应2 h,考察了不同相对分子量的PEG对改性后白炭黑产率和性能的影响,改性效果顺序是聚乙二醇PEG(6 000)>PEG(10 000)>PEG(20 000)。还考察了PEG相对添加量对改性后的白炭黑的产率以及性能的影响,PEG(6 000)相对添加量30%较为适宜。     

2-羟基-3,4,5-三甲氧基苯乙酮的合成

对半齿泽兰素重要中间体2-羟基-4,5,6-三甲氧基苯乙酮进行合成,以三甲氧基苯为起始原料,经氧化、还原、傅-克酰基化、水解、甲基化5步反应合成了目标产物,并采用单因素实验优化了各步反应条件,总收率48%。采用红外光谱、核磁共振氢谱等检测手段确证了中间体及产物的结构。     

氨基化单甲氧基聚乙二醇的合成研究

首先合成了单甲氧基聚乙二醇对甲苯磺酸酯(mPEG-OTs),然后根据盖布瑞尔合成法原理,以邻苯二甲酰亚胺钾盐(PPI)为亲核试剂与mPEG-OTs反应,生成单甲氧基聚乙二醇的邻苯二甲酰亚胺衍生物(mPEG-PI),mPEG-PI与水合肼反应肼解生成伯胺,合成了一端为氨基的单甲氧基聚乙二醇(mPEG-NH2)。讨论了缚酸剂、溶剂、反应条件对反应的影响。通过红外、液质联用、核磁共振谱图证实了产物与目标分子的结构相吻合。     

歧化松香聚乙二醇苹果酸酯的微波合成研究

在微波辐射下,先将歧化松香与聚乙二醇进行酯化反应,合成中间体歧化松香聚乙二醇酯,再将中间体与苹果酸进行酯化反应,合成目标产物歧化松香聚乙二醇苹果酸酯,研究了中间体和目标产物的合成条件。结果表明:①中间体合成的最佳条件为:反应时间90 m in,反应温度240℃,歧化松香与聚乙二醇的摩尔比为1∶1.6;②目标产物合成的最佳条件为:反应时间60 m in,反应温度140℃,微波功率800 W。利用IR、UV等测试技术对中间体及目标产物进行了结构表征,并测定了它们的主要表面性能。结果表明,中间体和目标产物均为性能优良的新型非离子表面活性剂。     

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。