新型聚天门冬氨酸酯聚脲的结构与性能

将聚天门冬氨酸酯(PAE)和端氨基聚醚与脂肪族异氰酸酯4,4′-二环己基甲烷二异氰酸酯预聚物反应,合成了4种新型PAE聚脲。用傅里叶变换红外光谱和差示扫描量热法考察了PAE聚脲的结构形态和热性质。结果表明,PAE聚脲脲羰基的总氢键化程度为69.9%～74.3%,其中较完善氢键化程度占47.8%～63.8%。采用不含侧甲基的PAE、降低软段用量或提高固化温度均可提高氢键化程度。PAE聚脲呈现部分微相分离状态,若采用不含侧甲基的PAE或增加软段含量,则软段和硬段相的混合程度提高。     

硬段含量对水性聚氨酯性能的影响

以聚酯多元醇和异佛尔酮二异氰酸酯(IPDI)为主要原料，引入亲水单体二羟甲基丙酸(DMPA)，按不同配比合成了系列聚氨酯乳液。考察了硬段含量对乳液粒径、表观黏度、膜吸水性、硬度、力学性能的影响，并通过动态力学性能测试(DMA)研究了软段和硬段的玻璃化转变温度。结果表明：提高-NCP/-0H物质的量之比、DMPA用量均使聚氨酯中软段的玻璃化温度Tg(s)降低，硬段的玻璃化温度Tg(h)升高，△T值增加，软硬段相分离程度增加。随乙二胺用量的增加，会使软段玻璃化转变温度Tg(s)移向高温，软硬段相分离程度降低；硬段含量提高，胶膜硬度增加，拉伸强度增加，胶膜耐水性降低。     

聚醚型聚氨酯的氢键、微相分离及性能

用本体一步法合成了5种不同硬段含量(11.0％～46.9％)的二苯甲烷-4,4′-二异氰酸酯/环氧乙烷封端型聚环氧丙烷聚醚/乙二醇的聚醚型聚氨酯,并借助于IR,DSC,DMS和材料试验机等手段对该聚氨酯的氢键、微相分离及力学性能进行了表征。结果表明:随着硬段含量的增加,其>NH与微区中的>C=O的氢键化程度逐渐提高,软段微区中—O—的氢键化程度逐渐降低;微相分离程度逐渐提高;拉伸强度及硬度随之增加,扯断伸长率在硬段含量40％左右出现极大值。     

氯水老化pH值对氨纶结构与性能的影响

为了研究氯水老化pH值对氨纶的影响,使用不同pH值的次氯酸钠溶液对氨纶进行老化处理,随后采用傅里叶变换红外光谱、X射线衍射、差示扫描量热及力学性能测试分析老化后样品的氢键化程度、微相分离程度、结晶性、热性能与拉伸性能。结果表明:氨纶氢键化程度、微相分离程度和硬段结晶度都随氯水p H值的降低而减弱。在热性能方面,随着氯水pH值的降低,氨纶的玻璃化转变温度与软段结晶熔融温度升高,软段结晶度减小。在拉伸力学性能方面,低pH值氯水处理后的氨纶表现出更小的断裂强力和断裂伸长率。     

H_(12)MDI聚氨酯弹性体微相分离研究

以4,4′-二环己基甲烷二异氰酸酯(H12MDI)/1,4-丁二醇(BDO)为聚氨酯硬段,分别以聚四氢呋喃醚二醇(PTMEG)、聚己二酸丁二醇酯(PBA)为软段合成了硬段含量(质量分数,下同)为23%～50%的聚氨酯弹性体。借助IR、DSC等分析手段研究了其微相分离结构,并针对所制备弹性体进行力学性能表征。结果表明,硬段含量对H12MDI基弹性体的软段玻璃化温度影响很小;硬段含量的增加,PTMEG型PU的微相分离程度随之先降低后增加,而PBA型PU的微相分离程度则随之降低;以PBA为软段的H12MDI基弹性体在硬段含量为40%时力学性能达到最优。     

粒料法合成聚氨酯分散体及性能的研究

以聚四氢呋喃二醇(PTMG)为软段,异氟尔酮二异氰酸酯(IPDI)和1,4-丁二醇(BDO)为硬段,二羟甲基丙酸(DMPA)为亲水单体,采用粒料法合成了聚氨酯离子聚合物粒料,制备了固含量为40%的聚氨酯分散体(PUD),研究了亲水含量和硬段含量对分散体性能及其胶膜性能的影响。PUD的ζ电位处于30~60 mV,黏度小于1100 mPa s。随着亲水含量增加,平均粒径减小,粒径分布变窄,黏度升高;硬段含量增加,平均粒径增大,粒径分布变宽,黏度降低。透射电镜显示,溶胶粒子呈大小不一的球形结构。PUD胶膜吸水率在3.15%~6.67%。力学性能测试表明硬段含量增加,断裂伸长率降低,拉伸强度增强。DMA测试显示胶膜出现相分离,有硬段和软段两个玻璃化转变温度。随着硬段含量增加,相分离程度提高,软段玻璃化温度降低,硬段玻璃化温度升高。     

羧酸型聚氨酯脲乳液的微相分离结构研究

利用ＤＳＣ,ＳＥＭ,ＷＡＸＤ对羧酸型聚氨酯脲乳液的微相分离结构进行了研究。结果表明,离子基团的引入,有利于软段和硬段的微相分离,随着离子基团含量的增加,微相分离程度增大。同时,适当增加硬段含量,硬段微区的有序性提高,结晶熔融温度升高。加入少量刚性物质ＭＯＣＡ,能够促进软段和硬段的微相分离。     

非离子型水性聚氨酯的制备及其涂膜表面性质研究

采用自乳化方法合成不同聚乙二醇(PEG)含量的非离子型水性聚氨酯乳液(WPU),并用傅里叶变换衰减全反射红外光谱(ATR-FTIR)、原子力显微镜(AFM)、接触角测量仪研究不同PEG含量对WPU涂膜表面性质的影响。结果表明:随着PEG含量的增加,WPU硬段与硬段之间氢键作用减弱,表现出硬软段微相分离程度降低;同时,WPU涂膜表面甲基含量增加,表面粗糙度下降,表现出涂膜表面能下降,水接触角增大。     

羧酸型聚氨酯脲乳剂的微相分离结构研究

利用ＤＳＣ，ＳＥＭ，ＷＡＸＤ对羧酸型聚氨酯脲乳液的微相分离结构进行了研究。结果表明，离子基团的引入，有利于软段和硬段的微相分离，随着离子基团含量的增加，微相分离程度增大。同时，适当增加硬段含量，硬段微区的有序性提高，结晶熔融温度升高。加入少量刚性物质ＭＯＣＡ，能够促进软段和硬段的微相分离。     

聚醚型聚氨酯弹性体的合成及其动态力学行为

采用两步合成法,以4,4′-二苯基甲烷二异氰酸酯(MDI)和1,4-丁二醇(BDO)为硬段,相对分子质量分别为1000、2000、4000的聚氧化丙烯二元醇(PPG)为软段,制备了一系列聚醚型聚氨酯(PUR)弹性体,研究了预聚体异氰酸酯指数R及软段相对分子质量对PUR动态力学性能的影响。结果表明,预聚体R值增大,即PUR的硬段含量增加,储能模量G′提高,软段相的玻璃化转变温度(Tg)升高,软硬相区的相容性增大;软段相对分子质量增加,PUR的G′下降,软段相的Tg降低,并出现硬段相的玻璃化转变,软硬相区的相分离程度增大。     

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。