聚醚型阳离子水性聚氨酯的合成及性能研究

采用异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇、亲水扩链剂和其他小分子多元醇反应合成阳离子水性聚氨酯乳液,讨论了不同异氰酸酯、扩链剂用量对阳离子水性聚氨酯乳液的状态、涂膜的耐水与机械性能的影响。结果表明,随异氰酸酯用量的增加,涂膜的强度及硬度逐渐提高,但涂膜的柔韧性降低、弹性下降;随N-甲基二乙醇胺(MDEA)用量的增加,涂膜的机械性能及耐水性降低;异氰酸酯的含量为47.3%、扩链剂MDEA的含量为4.3%时,乳液具有较好的贮存稳定性,且涂膜的断裂伸长率为1568%,48h吸水率为4%,具有较好的柔韧性及耐水性能。     

环氧改性聚氨酯光固化涂料研究

采用甲苯二异氰酸酯(TDI)、聚乙二醇(PEG)、二羟甲基丙酸(DMPA)和环氧树脂合成了环氧改性水性聚氨酯乳液。该乳液由于含有不饱和双键而具有感光性能,故可用作水性紫外光固化涂料或胶粘剂的预聚物。探讨了环氧丙烯酸酯(EB)和亲水扩链剂(DMPA)的添加量对涂料和涂膜性能的影响以及光引发剂用量、中和度对光固化涂料转化率的影响。结果表明,随着EB用量的增大,涂膜的硬度、耐水性、耐溶剂性及力学性能增强,但乳液外观和稳定性变差,故适宜的环氧树脂添加量为10%;随着DMPA用量的增加,涂膜硬度、强度提高,而断裂伸长率降低,耐水性变差,故DMPA用量在6%～8%范围为宜;光固化转化率随着中和度的提高而加快,适宜的引发剂用量为3%。本品的缺点是耐汽油性不够理想。     

丙烯酸酯含量对水性聚氨酯性能的影响

采用无皂种子乳液聚合法,以甲苯二异氰酸酯(TDI)、聚酯多元醇、二羟甲基丙酸(DMPA)和甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)等为主要原料合成丙烯酸酯-水性聚氨酯复合乳液,考察了丙烯酸酯含量对水性聚氨酯乳液粒径、运动黏度、胶膜的耐水性和力学性能的影响。试验结果表明,随着丙烯酸酯含量的增加,复合乳液的粒径增大,运动黏度减小,胶膜的耐水性和拉伸强度提高,但胶膜的断裂伸长率有所降低,适宜的丙烯酸酯用量为40%～50%。     

不同二胺后扩链对聚酯/聚醚型水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(N210)、聚酯二元醇(PBA)为主要原料,二羟甲基丙酸(DMPA)为亲水性扩链剂,一缩二乙二醇(DEG)为小分子扩链剂,乙二胺(EDA)、异佛尔酮二胺(IPDA)为后扩链剂,合成了一系列水性聚氨酯(WPU)乳液。主要考察了后扩链对水性聚氨酯乳液的稳定性,乳液粒径以及胶膜吸水率和力学性能的影响。结果表明,用二胺后扩链之后,乳液稳定性变好,乳液粒径变小,胶膜吸水率减小,耐水性变好,胶膜拉伸强度增加,当采用IPDA后扩链且质量含量为2.7%时,膜的综合性能较好,吸水率相对较低(16.7%),拉伸强度为31.23MPa,断裂伸长率为1022.31%。     

端羟基聚丁二烯改性水性聚氨酯的合成与性能

以端羟基聚丁二烯(HTPB)、聚醚二元醇(N-220)、异佛尔酮二异氰酸酯(IPDI)为主要原料,制备了改性水性聚氨酯(WPU)。研究了端羟基聚丁二烯(HTPB)的含量对聚氨酯乳液粒径、贮存稳定性,以及对涂膜耐水性、力学性能、低温柔韧性的影响。结果表明:在预聚反应中,固定总n(—NCO)∶n(—OH)为1.3,w(DMPA)为6%,HTPB添加量在40%(占聚醚N-220的量)以下时,粒径变化不大,乳液稳定性较好;针对不同HTPB添加量,控制好亲水基团的含量,可以获得分散性良好、贮存稳定的聚氨酯乳液;随着HTPB添加量逐渐增大,涂膜的拉伸强度逐渐增大后变小,断裂伸长率和吸水率逐渐减小后变大,低温柔韧性变好。当HTPB添加量在30%左右,涂膜的综合性能最佳。     

硬段含量对聚酯型水性聚氨酯的影响

以聚已二酸新戊二醇酯二醇(PNA)和异佛尔酮二异氰酸酯(IPDI)为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,一缩二乙二醇(DEG)为小分子扩链剂,合成了一系列水性聚氨酯乳液.采用傅里叶红外光谱对水性聚氨酯的结构进行表征,并考察了不同DMPA含量、不同IPDI与PNA配比对乳液粒径及涂膜吸水率、机械力学性能、耐热性的影响.结果表明,提高DMPA含量使乳液粒径逐渐减小,增大异氰酸酯与多元醇物质的量比n(-NCO)/n(-OH)使乳液粒径增加;DMPA含量或n(-NCO)/n(-OH)的提高,均能提高涂膜的拉伸强度,但涂膜的断裂伸长率降低且吸水率增加.热重分析表明n(-NCO)/n(-OH)比例的增加使涂膜的耐热性降低.     

聚醚型硅油改性水性聚氨酯的制备与性能研究

以异佛尔酮二异氰酸酯、聚四氢呋喃醚二醇、二羟甲基丙酸、聚醚型硅油等为原料制备了硅改性水性聚氨酯(PUDS)。采用红外光谱、透射电镜等对PUDS乳液及其涂膜进行了结构表征和性能测试,结果表明:有机硅有效地接枝在水性聚氨酯分子链上,涂膜耐水性显著提高,乳液稳定性良好,随着聚醚型硅油用量的增加,涂膜拉伸性能呈微弱下降趋势,当硅油用量为2%时,拉伸强度为16.7 MPa,断裂伸长率为753.7%,断裂强度15.8 MPa,综合性能优良。     

磺酸/羧酸型高固含量水性聚氨酯的制备及其性能

以二羟甲基丙酸(DMPA)、A95氨基磺酸钠(固含量50%)为扩链剂,将羧基和磺酸基团同时引入到聚氨酯分子中,合成了一系列磺酸/羧酸型高固含量水性聚氨酯(ZW1~ZW4),研究了磺酸基用量对水性聚氨酯性能的影响。利用傅里叶变换光谱仪、X射线衍射仪对合成的水性聚氨酯进行检测,结果表明反应按照预期路线进行。乳液性能测定结果表明,随着磺酸基用量的增加,乳液固含量增大,粒径减小且分布变宽,Zeta电位由-44.5 m V降低到-62.7 m V,但耐酸稳定性有所下降。胶膜性能测定结果表明,随着磺酸基的增加,胶膜的断裂伸长率由2 100%增加到2 800%,抗张强度从28 MPa下降到14 MPa,结晶度增大。此外,耐热性和耐水性都有所下降。     

HDI型水性聚氨酯胶粘剂的制备与性能研究

以聚酯二元醇、二异氰酸酯(HDI)与2,2-二羟甲基丙酸(DMPA)为主要原料,采用丙酮法合成了HDI型水性聚氨酯(WPU),探讨了亲水扩链剂DMPA用量对WPU乳液粒径、耐水性、耐热性及剥离强度等性能的影响。结果表明:随着DMPA含量不断增加,WPU乳液粒径减小,WPU膜的吸水强度、耐热性和剥离强度先升高后降低。当R(NCO/OH)值为2.226,扩链剂DMPA的加入量为3.5~4%时,可获得综合性能较好的水性聚氨酯。     

可控交联度的大豆油基水性聚氨酯的制备与研究

以丙烯酸(AA)作为开环试剂,与环氧大豆油(ESO)反应制备可控羟基数的多元醇(AESO),再与聚醚二醇(PPG)、异氰酸酯(IPDI)、亲水单体二羟甲基丙酸(DMPA)、扩链剂三羟甲基丙烷(TMP)和中和剂三乙醇胺(TEA)等原料,制备出性能良好的大豆油基水性聚氨酯乳液(SWPU)。通过傅里叶变换红外分析、热重分析和机械测试研究了涂膜的结构和物理性能,研究了AESO和PPG相对含量的变化对SWPU的黏度和稳定性以及涂膜的耐水性、热稳定性及力学性能的影响。结果表明:成功地以AESO改性水性聚氨酯,得到的SWPU乳液具有较好的稳定性,涂膜耐水性得到改善,且具有较好的热稳定性,拉伸强度得到提高,断裂伸长率有所下降。     

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。