聚丙烯酸钾与腐植酸复合高吸水性树脂的合成研究

以腐植酸与丙烯酸聚合制备了高吸水性树脂,讨论了交联剂、引发剂以及KOH用量对聚丙烯酸与腐植酸高吸水性树脂吸水率的影响,结果显示在n(MBA)∶n(AA)=0.0005、n(KPS)∶n(AA)=0.0075、n(KOH)∶n(AA)约为0.70、温度为80℃的条件下合成时,其吸水倍率可达到最优值。而且在接近自然条件下(35℃)失水速度慢,保水时间可达100 h以上,重复吸水性能好。运用红外光谱分析了腐植酸与丙烯酸的反应机理。     

聚丙烯酸盐类高吸水性树脂的合成研究

以部分中和的丙烯酸为基本单体，采用反相悬浮聚合法，对聚丙烯酸钾、聚丙烯酸铵高吸水性树脂的合成条件进行了研究，获得了吸水树脂的吸液率与交联剂用量、引发剂用量、pH值等影响因素的关系，并利用共聚方法改进了吸水树脂的耐盐性，研制出了性能优良的高吸水性树脂。所制高吸水性树脂吸去离子水倍率≥1200mL/g（最高达2700mL/g)；耐盐性高吸水性树脂吸0．9％ NaCl水溶液倍率≥150mL/g(最高达260mL/g)。     

聚乙二醇单酯的合成及其在高吸水性树脂中的交联作用

合成了正丁氧基聚乙二醇甲基丙烯酸酯交联剂 ,通过反相悬浮聚合考察了其对高吸水性树脂吸水性能的效果 ,探讨了聚乙二醇分子量等交联剂合成条件与用量对吸水性树脂性能的影响 ,发现聚乙二醇相对分子质量为 40 0～ 80 0时高吸水树脂吸水性能较好 ,吸水倍率为 35 0～ 5 0 0g/g ,吸盐水倍率超过 6 0g/g ,加压吸水倍率变化小     

丙烯酸/丙烯酰胺/丙烯腈三元共聚制备耐盐高吸水性树脂的研究

采用过硫酸铵作为引发剂,N,N-二甲基双丙烯酰胺作为交联剂,通过水溶液共聚法制备了丙烯酸、丙烯酰胺、丙烯腈高吸水性共聚物,探讨了合成过程中各种影响因素对高吸水性树脂性能的影响。结果表明,当反应单体配比n(丙烯酸)∶n(丙烯酰胺)∶n(丙烯腈)=15∶4∶6,引发剂用量为单体总质量的0.05%,交联剂用量为单体总质量的0.015%,反应温度为80℃,反应时间为3 h,中和度为75%的条件下,所得高吸水性树脂的吸去离子水能力可达990 g/g以上,吸0.9%氯化钠溶液能力达190 g/g以上。     

壳聚糖接枝共聚制备高吸水性树脂的合成与表征

在水溶性氧化还原体系引发剂NaHSO3/K2S2O8的引发下,使丙烯酸(AA),丙烯酰胺(AM)在壳聚糖(CTS)分子链上接枝聚合,并加入N,N′-亚甲基双丙烯酰胺(MBAM)进行一定程度的交联,制得高吸水性树脂。研究了反应条件对所得树脂吸水性能的影响。结果表明,使树脂具有最高吸水性能的最优化反应条件为:m(CTS)∶m(AA)∶m(AM)为1∶3∶1,丙烯酸的中和度为70%,引发剂用量4%,交联剂用量0.04%,反应温度45°C。在此条件下合成的树脂最大吸水倍率可达402 g/g,吸盐水(浓度0.9%)倍率可达102 g/g,定性观察该高吸水性树脂的凝胶强度为良。最后采用SEM和TG对所合成的树脂进行了结构和性能表征。     

黄原胶接枝改性制备高吸水性树脂的研究

以丙烯酸和丙烯酰胺为单体,采用溶液聚合方法对黄原胶进行接枝改性,制备了黄原胶基新型高吸水性树脂。利用正交实验研究了引发剂用量、聚合反应温度、丙烯酸中和度、黄原胶与单体AA和AM质量比和交联剂用量等因素对合成高吸水性树脂的影响,利用傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)对树脂进行了表征。实验结果表明,最佳合成聚合反应温度为65℃,m(黄原胶)∶m(AA)∶m(AM)=1∶5∶1,w(引发剂)=1.5%,丙烯酸中和度为70%,w(交联剂)=0.06%。红外光谱分析结果表明,丙烯酸和丙烯酰胺接枝到黄原胶分子链上;扫描电镜观察结果表明,树脂形成一种多孔网络结构。最佳合成条件下制备的高吸水性树脂吸自来水倍率达869.0 g/g,吸盐水倍率为126.7 g/g,重复利用性较好。     

复合交联剂型高吸水树脂的超声制备与性能研究

以N,N′-亚甲基双丙烯酰胺(NMBA)和聚乙二醇(PEG)为复合交联剂,以丙烯酸(AA)、丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,在无任何助剂下超声辐射合成AA/AM/AMPS共聚高吸水性树脂,研究了反应条件对树脂吸水倍率的影响,并对树脂的吸水性能进行了测试,用红外光谱(FT-IR)和AFM对树脂的结构和表面形态进行了表征.结果表明:在优化条件下合成的高吸水性树脂其吸蒸馏水和生理盐水分别为1342 g/g和92 g/g;表征分析证实,复合交联剂通过化学交联和物理交联的协同作用可以有效改善树脂的凝胶强度、耐热性、保水性和再生性.     

微波辐射合成P(AA-AM)高吸水树脂

对微波辐射下丙烯酸(AA)和丙烯酰胺(AM)的水溶液聚合反应进行研究,合成P(AA-AM)高吸水性树脂,探讨丙烯酸中和度、单体配比、微波辐射时间、交联剂用量和引发剂用量等对吸液倍率的影响,并用红外光谱对产物的结构进行表征.40 s合成的高吸水性树脂吸水倍率可达1600 g/g,在质量分数为0.9%的食盐水中的吸液倍率达160 g/g.     

具有高通液性能高吸水性树脂的制备及性能研究

以丙烯酸、功能单体为聚合单体,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用水溶液聚合法合成了一种具有优异通液性能和吸液性能的高吸水性树脂,研究了自制功能单体用量、交联剂用量、引发剂用量、中和度、引发温度对高吸水性树脂吸液能力和通液能力的影响,并使用扫描电镜对高吸水性树脂的颗粒形态进行表征。结果表明,合成最佳条件为：丙烯酸用量为250 g,功能单体用量为25 g,交联剂用量为1.5 g,引发剂用量为0.375 g,氢氧化钠用量为97.2 g,引发温度为55℃。此条件下制备得到的高吸水性树脂具有良好的吸液性能和通液性能,吸盐水倍率为103.25 g/g,通液速度为201.55 mL/min。扫描电镜结果表明高吸水性树脂由于分子链的刚性变强,颗粒表面形状更规则。     

羧甲基壳聚糖-丙烯酸高吸水性树脂的制备及性能

以羧甲基壳聚糖(CMCS)为基体,丙烯酸(AA)为接枝单体,过硫酸铵(APS)为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用水溶液聚合法制备出羧甲基壳聚糖-丙烯酸高吸水性树脂(CMCS-AA SAP)。研究了CMCS粘度对树脂吸液性能的影响。结果表明,一定范围内,随着CMCS粘度的增加,CMCS-AA高吸水性树脂网络结构更加紧密,吸水性能得到提高。合成工艺优化结果显示,在交联剂(MBA)用量为0.025%(以AA质量为基准,下同),引发剂(APS)用量为0.093 75%,AA中和度为80%的条件下,树脂的吸水倍率达1 011.21 g/g,吸盐倍率达85.74 g/g,树脂有着良好的pH敏感性。     

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。