盐酸水解制备红薯微孔淀粉的研究

研究在不同的盐酸浓度、温度、淀粉用量和反应时间条件下,通过单因素实验和正交实验取得最佳工艺条件。利用盐酸水解红薯淀粉制备微孔淀粉,通过吸油率考察了微孔淀粉吸附性能。盐酸浓度为1.5%、温度为45℃、淀粉用量为20g、反应时间为8h时,制备红薯微孔淀粉的吸附性能最佳。     

多孔淀粉的制备研究

以玉米淀粉为原料,在一定条件下制备多孔淀粉。通过考察盐酸浓度、反应温度、反应时间对多孔淀粉吸油率的影响,确定了多孔淀粉的最佳制备工艺条件:HCl浓度为10%,反应温度为40℃,反应时间为10 h。在优化条件下进行多次重复试验,得产物平均吸油率在107%左右。用扫描电镜(SEM)检测,淀粉表面呈稀疏的孔状,说明产品为多孔淀粉。     

牛皮纸制备高吸水树脂及结构表征

将牛皮纸进行碱处理,制成微晶纤维素,与淀粉、丙烯酸钠通过反相悬浮聚合法接枝成高吸水树脂。正交实验表明,最佳工艺条件为:反应温度55℃,反应时间3h,丙烯酸中和度75%,交联剂、引发剂、淀粉及纤维素用量分别为单体质量的0.6%,0.5%,10%,10%,对最佳条件下制备的树脂进行吸水倍率测试,并用透反显微镜清晰观察到树脂吸水后的网络结构。结果表明,该吸水树脂具有良好的吸水性能,吸蒸馏率达727.8g/g,吸盐水率达70.8g/g。     

交联剂种类及用量对淀粉类吸水树脂吸水性能的影响

以玉米淀粉、丙烯酸、膨润土为原料,过硫酸铵为引发剂,采用水溶液聚合法制备超强吸水树脂,并对产物进行性能测试。在得到最佳反应条件的基础上,考察了不同交联剂对此类超强吸水树脂性能、结构的影响,并优选较适合淀粉类超强吸水树脂的交联剂。以AlCl3为交联剂,且AlCl3用量为0.015%时,所得超强吸水树脂的吸去离子水量达到最高,为433.96 g/g,AlCl3用量为0.01%时,吸0.9%的NaCl溶液量达到最高,为73.76 g/g。     

淀粉——海藻酸系高吸水性树脂的制备

本文以玉米淀粉和海藻酸钠为原料、丙烯酸为反应单体、以过硫酸胺为引发剂、N,N′-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法,制备出吸水性能较好的淀粉-海藻酸系树脂,并进一步通过对海藻酸钠用量、反应引发剂用量和交联剂用量对淀粉-海藻酸系高吸水树脂吸水倍率的影响进行实验分析,得出最佳的合成工艺条件。     

多孔玉米淀粉吸油材料制备及性能

利用α-耐高温淀粉酶酶解法制备多孔玉米淀粉吸油材料,以吸油率为衡量指标设计实验优化多孔玉米淀粉的制备条件。结果表明,酶解温度50℃、酶解p H值为5.0、酶添加量3%、酶解时间12h、底物浓度25%,该条件下吸油率最高可达112.04%,对油脂吸附效果良好,其吸油率、比容积、膨胀率、透光率及溶解率性能指标比玉米淀粉分别提高了82.30%、21.94%、38.29%、7.39%、69.83%。FTIR分析表明,酶解作用使得玉米淀粉只是特征吸收峰有略微变化,并没有使玉米淀粉的分子结构发生显著改变;SEM分析显示,多孔玉米淀粉颗粒完整,孔洞明显,成孔效果良好,有利于增加比表面积,提升吸油性能。     

超吸水性接枝共聚淀粉篚制备工艺研究

以玉米淀粉为原料,丙烯酸为接枝单体,K2S2O8-Na2S2O3为引发剂,制备了丙烯酸接枝淀粉超强吸水剂。通过正交实验优化了接枝工艺,并以吸水倍率为指标,确定了最佳工艺条件：淀粉与丙烯酸质量比1：4,引发剂用量为淀粉质量的3．5％,交联剂用量为淀粉质量的0．8％,接枝温度为35℃,接枝时间为2h。在此条件下合成的丙烯酸接枝淀粉超强吸水剂对纯水的吸水倍率可达368％。     

淀粉接枝可降解性高吸水树脂的制备与性能研究

针对吸水树脂使用过程中存在的吸盐水倍率低,降解性能差等问题,以过硫酸钾为引发,N,N'-亚甲基双丙烯酰胺为交联剂,环己烷为连续相,玉米淀粉,丙烯酸和丙烯酰胺为原料,采用反相悬浮聚合法合成淀粉接枝可降解高吸水性树脂微球并进行了相关表征。最佳反应条件下,得到的吸蒸馏水倍率为379.2 g/g,吸0.9%的Na Cl水溶液的倍率为88.1 g/g。最后考察了吸水树脂的保水性能和降解性能,从而为吸水树脂微球应用于农林业保水保肥提供理论指导。     

微孔淀粉的工艺研究

微孔淀粉是一种新型的变性淀粉。介绍了酸法和高温α-淀粉酶与糖化酶联用的方法水解玉米淀粉制备微孔淀粉,通过比较发现酶法优于酸法。并且当高温α-淀粉酶与糖化酶联用重量比为1∶3、pH=4.5、50℃、水解18 h时,可获得吸油率较高的微孔淀粉。     

酶解法制备木薯多孔淀粉的工艺研究

分别采用α-淀粉酶、葡萄糖淀粉酶和复合酶水解淀粉得到多孔淀粉,并通过分析测试不同水解条件下多孔淀粉的吸油率和微观形貌,研究酶的种类以及水解时间对多孔淀粉性能的影响。结果表明,采用复合酶（葡萄糖淀粉酶∶α-淀粉酶=3∶1）水解16h得到的多孔淀粉的吸油率最大,达到了31.84%。在多孔淀粉的制备过程中,采用复合酶水解16h得到的多孔淀粉的吸油性能最佳。     

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.     

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。     

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.