蓖麻油聚氨酯互穿网络型聚合物性能的研究

分别用甲苯二异氰酸酯(TDI)和六亚甲基二异氰酸酯(HDI)与蓖麻油(CO)反应制备出两种聚氨酯预聚体,再用预聚体与苯乙烯、丙烯腈、甲基丙烯酸甲酯、环氧树脂(E-44或E-51)等单体制备出蓖麻油聚氨酯互穿网络型聚合物(CO-PU IPN),研究了体系组成对该聚合物拉伸强度的影响。结果表明,随着固化时间的延长,CO-PU IPN的拉伸强度逐渐增大,TDI型CO-PU IPN比HDI型的拉伸强度大;烯类单体比环氧树脂单体所制CO-PU IPN的拉伸强度大,不同烯类单体之间的差别不大;增加预聚体中NCO/OH的摩尔比,CO-PU IPN的拉伸强度都是先增加,后减小,在摩尔比为2.25时出现最大值;添加抗氧剂1010、紫外光吸收剂UV-327和光稳定剂292等对CO-PUIPN的拉伸强度基本没有影响。     

脂肪族蓖麻油聚氨酯互穿网络型聚合物拉伸强度的研究

用蓖麻油(CO)、六亚甲基二异氰酸酯(HDI)和单体交联剂苯乙烯(St)、丙烯腈(AN)、甲基丙烯酸甲酯(MMA)为主要原料,制得了HDI/St、HDI/AN和HDI/MMA等3种蓖麻油/聚氨酯互穿网络型聚合物(CO-PU IPN);研究了CO-PU IPN组成对拉伸性能的影响,并利用红外光谱分析对IPN的潮气固化过程进行了分析。结果表明,随着固化时间的延长,CO-PU IPN的拉伸强度逐渐增大,6d后基本达到最大值;HDI/St、HDI/AN和HDI/MMA型CO-PU IPN的拉伸强度差别不大;增加预聚体中NCO/OH的摩尔比nNCO/nOH,CO-PU IPN的拉伸强度都是先增加,后减小,在nNCO/nOH为3·25时出现最大值。     

合成温度对PCL型聚氨酯弹性体性能的影响

以聚己内酯二元醇(PCL-2000)、甲苯二异氰酸酯(TDI)、3,3’-二氯-4,4’-二氨基二苯甲烷(MOCA)为原料,采用预聚体法合成浇注型聚氨酯弹性体(CPU)。研究了预聚体温度,后熟化温度对聚氨酯弹性体力学及耐热性能的影响。实验结果表明:随着预聚体温度升高,CPU拉伸强度增大,压缩永久形变(80℃×24 h)逐渐变小。随着后熟化温度升高,CPU拉伸强度先增大后减小,压缩永久形变(80℃×24 h)先减小后增大。当预聚体温度为110℃时,拉伸强度达到50 MPa,断裂伸长率达到356%。压缩永久形变80℃×24 h为36%。     

蓖麻油改性磺酸型水性聚氨酯性能研究

采用蓖麻油、异佛尔酮二异氰酸酯(IPDI)、聚己内酯二元醇(PCL)和1,4-丁二醇(BDO)为主要原料,以乙二胺基乙磺酸钠(AAS)为亲水基,合成了一系列由蓖麻油改性的磺酸型水性聚氨酯乳液,并固化成膜。通过FT-IR、粒径测试、吸水率与接触角测定、力学性能测定、TG等手段研究了蓖麻油含量对水性聚氨酯乳液与胶膜的影响。结果表明:蓖麻油成功接入聚氨酯分子主链中;随着蓖麻油含量的增加,乳液粒径逐渐增大;胶膜的吸水率先减小后增大,接触角先增大后减小,拉伸强度先增大后减小,断裂伸长率逐渐减小。当蓖麻油与PCL质量比为0.5时,胶膜吸水率最小,接触角最大,为95.18°,拉伸强度最大,为15.15 MPa,综合性能最好。通过TGA表明,蓖麻油的引入,胶膜的耐热性也有所提高。     

蓖麻油TDI聚氨酯预聚体的制备

利用双键含量、异氰酸酯根(-NCO)含量和游离甲苯二异氰酸酯(TDI)含量的测定,研究了反应条件对蓖麻油聚氨酯预聚体(CO-PU)合成的影响。结果表明,随着反应温度的升高,CO-PU中剩余-NCO的含量逐渐减少,游离TDI含量逐渐降低;增加nNCO/nOH,CO-PU中剩余-NCO和游离TDI含量增大;延长反应时间,-NCO含量减小;加入二丁基二月桂酸锡(DBTDL)后,酯化反应速率加快,体系中-NCO含量明显降低。在-NCO与羟基的反应过程中双键比较稳定,CO-PU中的双键含量基本不变。     

聚氨酯-环氧树脂弹性体的合成

首先由聚醚(PPG)和甲苯二异氰酸酯(TDI)反应制得含有端异氰酸酯的预聚体,利用预聚体中的异氰酸酯基团与环氧树脂上的仲羟基反应合成端环氧基团的聚氨酯-环氧树脂,然后用低分子聚酰胺固化.通过改变预聚体中PPG3031含量和NCO/OH的比值得到不同的拉伸强度和硬度.实验结果表明:随着预聚体中PPG3031含量的增大,弹性体的拉伸强度增大,硬度也增大;随着预聚体中NCO/OH摩尔比的提高,弹性体的拉伸强度和硬度增大,断裂伸长率变化不大.     

聚碳酸酯二醇/蓖麻油基聚氨酯(脲)弹性体的制备及性能

以蓖麻油和聚碳酸酯二醇(PCDL)为共混软段,分别以1,4-丁二醇(BDO)和3,5-二甲硫基-2,4-二胺基甲苯(DMTDA)为扩链剂,用预聚体法合成出一系列聚氨酯(PU)和聚氨酯脲(PUU)弹性体,考察了异氰酸基(NCO)含量和PCDL用量对弹性体力学性能的影响,并对弹性体的热性能进行了分析。结果表明,随着预聚体中NCO含量的增加,PU、PUU弹性体的硬度和强度逐渐上升,当NCO质量分数为8%时,弹性体的拉伸强度最高,而扯断伸长率呈单调下降趋势;随着PCDL用量的增加,弹性体的拉伸强度先升高后下降,扯断伸长率和永久变形逐渐增加;用DMTDA为扩链剂制备的PUU比用BDO制备的PU具有更高的拉伸强度和撕裂强度;PCDL/蓖麻油基PUU的耐热性能优于纯蓖麻油基PUU,PUU的耐热性优于PU。     

改性醇溶性聚氨酯制备及其性能评价

首先制备了改性醇溶性聚氨酯复合材料,继而分析了预聚前后蓖麻油添加量对聚氨酯胶膜吸水率、剥离强度、力学性能的影响,结果表明:(1)预聚前加入蓖麻油,所生成的胶体质量较好;预聚后加入蓖麻油,聚合过程不容易控制,且胶膜略微发粘;(2)聚氨酯中-NOC键与羟基键数量比值越大,胶膜拉伸强度越大,断裂伸长率越小;(3)在油溶性聚氨酯中随着蓖麻油添加量逐渐增大,胶膜吸水率逐渐减小。     

聚氨酯/环氧树脂互穿网络聚合物硬质泡沫机械性能研究

采用同步法合成了聚氨酯/环氧树脂互穿网络聚合物(PU/EP IPN)硬质泡沫,对机械性能进行了研究。结果表明,与纯聚氨酯硬质泡沫相比,PU/EP IPN硬质泡沫的压缩强度和弯曲强度明显提高,在PU/EP IPN硬质泡沫中,随环氧树脂含量增加,PU/EP IPN硬质泡沫压缩强度和弯曲强度随之增大,当E-39D质量分数增加到24.2%时,PU/EP IPN硬质泡沫压缩强度和弯曲强度出现最大值;PU/EP IPN硬质泡沫机械强度随材料密度的增大而增加;随着环氧树脂中环氧值的增加,PU/EP IPN硬质泡沫的压缩强度、弯曲强度和拉伸强度均呈逐渐升高的趋势。     

原位反应生成的甲基丙烯酸镁对混炼型聚氨酯补强的研究

在混炼型聚氨酯(MPU)(过氧化物作硫化剂)混炼过程中,氧化镁(MgO)与甲基丙烯酸(MAA)原位反应生成甲基丙烯酸镁(MDMA),研究其对MPU的补强作用。结果表明:当MDMA理论生成量为30份时,随着MgO/MAA物质的量比的增大,MPU硫化胶的拉伸强度先增大后减小,当MgO/MAA物质的量比为0. 6时,拉伸强度达到最大值,综合物理性能最佳;当MgO/MAA物质的量比为0. 6时,随着MDMA理论生成量的增大,混炼胶的F_(max)-F_L显著提高,MPU硫化胶的拉伸强度先增大后减小,玻璃化温度向低温移动,耐低温性能提高,在MDMA用量为30份时,拉伸强度达到最大值,填料网络结构较稳固。     

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。