耐盐型高吸水性树脂的合成及性能评价

以氧化还原引发剂(NH4)2S2O8和N aHSO3为引发剂,采用水溶液法合成了丙烯酸钠—丙烯酰胺—疏水单体共聚高吸水性树脂。研究了单体聚合浓度、单体含量及引发剂用量等对共聚高吸水树脂吸水率的影响。实验证明该高吸水聚合物耐盐性较好。     

水溶液聚合法合成高吸水性树脂的研究

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾-亚硫酸氢钠为引发剂,以丙烯酸和丙烯酰胺为单体,采用水溶液聚合法合成了丙烯酸-丙烯酰胺共聚的吸水树脂,并探讨了单体浓度、单体质量比、丙烯酸中和度、交联剂用量、引发剂用量对吸水树脂吸水量的影响,最大吸水率为799.3 g/g。     

耐盐型丙烯酸-丙烯酰胺接枝共聚高吸水树脂的合成及其性能研究

采用溶液聚合法,以丙烯酸(AA)和丙烯酰胺(AM)为单体,N,N＇-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂.合成出丙烯酸-丙烯酰胺接枝共聚高吸水树脂.探讨了单体比[m(丙烯酸):m(丙烯酰胺)]、交联剂和引发荆用量、单体中和度及聚合温度对树脂吸水率的影响.IR光谱表明,丙烯酸和丙烯酰胺发生了接...     

丙烯酸-丙烯酰胺共聚物吸水树脂的制备

采用溶液聚合法,以丙烯酸(AA)和丙烯酰胺(AM)为单体,N,N’-亚甲双丙烯酰胺(NMBA)为交联剂,过硫酸铵为引发剂,制备了丙烯酸-丙烯酰胺共聚物吸水树脂,探讨了单体配比(mAA/mAM)、交联剂和引发剂用量对树脂吸水率的影响。结果表明:在65℃时,丙烯酸-丙烯酰胺共聚物吸水树脂的最佳制备条件为:丙烯酸和丙烯酰胺质量比为4:1,交联剂和引发剂用量分别为聚合单体(丙烯酸和丙烯酰胺)总质量的0.02%和0.4%。     

淀粉-丙烯酸-丙烯酰胺高吸水性树脂的紫外光聚合及性能研究

采用紫外光引发聚合的方法制备淀粉-丙烯酸-丙烯酰胺高吸水性树脂,研究了淀粉用量、单体配比、丙烯酸中和度、交联剂、光引发剂等因素对吸水率的影响。当固化时间15min,淀粉用量10%(占丙烯酸用量的质量百分比).光引发剂用量0.4%,交联剂用量0.02%,中和度85%,丙烯陂/丙烯酰胺(摩尔比)10.可制得吸水率为985.1g/g的吸水树脂。     

淀粉接枝聚合制备高吸水性树脂

以红薯淀粉为主要原料,选用丙烯酸和丙烯酰胺为改性单体,经过接枝共聚制备高吸水性树脂,分别考察单体、引发剂和交联剂用量对树脂吸水率的影响,并对树脂吸水动力学进行了初步研究.实验结果显示:当单体、引发剂和交联剂用量分别为淀粉的4倍、5%和0.8%时,高吸水性树脂吸水率最高;该树脂吸水的一级速率过程常数为0.0537min-1.     

淀粉接枝共聚合成吸水树脂工艺研究

以淀粉为原料,丙烯酸和丙烯酰胺为共聚单体,过硫酸铵为引发剂,N,N‘-亚甲基双丙烯酰胺为交联剂,采用接枝共聚法制备吸水树脂。研究了引发剂用量、交联剂量、单体与淀粉质量比以及丙烯酸和丙烯酰胺质量比对产品的吸水率的影响。实验结果表明：当引发剂占干物料质量的0．6％,交联剂质量占单体质量的0．8‰,单体与淀粉质量比为4,丙烯酸与丙烯酰胺质量比为1．33,产品的吸水率可超过550。     

接枝共聚法制备超强吸水剂

以淀粉为原料,丙烯酰胺为单体,硫酸铈铵为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,采用接枝共聚法制备超强吸水剂。研究了引发剂浓度、交联剂用量、单体与淀粉质量比及氢氧化钠用量对产品吸水率的影响。实验结果表明:当引发剂浓度为5.0×10-3mol/L;交联剂用量占单体质量的0.20%;单体与淀粉质量比为1∶3;氢氧化钠用量占单体质量为30%时,产品的吸水率可达1000倍以上。     

蒙脱土改性三元共聚高吸水树脂制备与性能研究

以酸处理有机蒙脱土为改性剂,采用水溶液聚合法制备蒙脱土改性丙烯酸基三元共聚高吸水性树脂。在丙烯酸∶丙烯酰胺∶烯丙基磺酸钠单体质量配比为8∶4∶0.5,中和度70%,反应温度75℃,交联剂用量为单体的0.1%,引发剂用量为单体的0.18%和有机蒙脱土用量为单体的4%条件下,所制得树脂的吸水倍率、吸生理盐水倍率和吸人工尿液倍率分别为735.6,58.5,46.6 g/g。     

木薯淀粉接枝丙烯酸-丙烯酰胺吸水剂合成研究初探

用过硫酸钾做引发剂,通过水溶液聚合法制得了木薯淀粉接枝丙烯酸和丙烯酰胺高吸水性树脂.研究了丙烯酸与丙烯酰胺用量比、反应温度及引发剂用量等对吸液性能的影响,分析了木薯淀粉在接枝前和接枝后的结构和性能.最佳反应条件为:丙烯酸/丙烯酰胺质量比1∶3,引发剂过硫酸钾用量是单体质量的0.125%,交联剂N,N'-亚甲基双丙烯酰胺的用量为单体质量的0.167%.反应温度为70℃,反应时间为4 h.     

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。