二异氰酸酯改性环氧树脂胶粘剂的研制

本文用甲苯二异氰酸酯(TDI)改性环氧树脂,合成了具有稳定的聚(口恶)唑烷酮环状结构的环氧树脂胶粘剂,用IR表征了树脂的结构,表明其有明显的聚(口恶)唑烷酮吸收峰。对固化剂、固化时间及固化温度进行了选择,利用正交试验方法选出了胶粘剂的最佳配方。实验结果表明:该胶粘剂剪切强度比未改性环氧树脂提高一信,对A1-A1室温粘合达29.0MPa,在110℃下剪切强度达15.5MPa,而且加快了固化速度,耐水性能亦优良,是一种很有发展前途的胶粘剂。     

低溴环氧/氰酸酯树脂共固化反应及其层压板性能的研究

用差示扫描量热仪(DSC)、傅立叶交换红外光谱(FT-IR)对不同配比的低溴环氧／氰酸酯树脂的共固化反应机理以及固化物的结构特征进行了研究,同时测定和讨论了其层压板的耐热性和介电性能等。研究结果表明,在低溴环氧／氰酸酯树脂的固化体系中,氰酸酯和环氧树脂通过两种途径反应最终生成噁唑烷酮结构：固化反应温度与体系的组成有关,体系中低溴环氧树脂减少固化反应温度降低：加入催化剂能明显促进体系共固化反应,同时也降低了层压板的耐热性和介电性能。在性能方面,低溴环氧树脂中加入氰酸酯使共固化物耐热性增加、Tg升高,但氰酸酯用量增加到一定范围后,低溴环氧树脂／氰酸酯配比对Tg影响不大;低溴环氧树脂／氰酸酯层压板的耐热性和介电性能在一定实验范围内随着氰酸酯用量的增加明显提高。     

玉米秸秆木质素改性环氧树脂的制备与性能

将玉米秸秆木质素与双酚A环氧树脂混合,于100℃下预处理1 h,以改善环氧树脂的性能。对预处理后环氧树脂的黏度进行了测试,对改性环氧树脂与聚酰胺固化后材料的力学性能、动态力学性能、热稳定性以及燃烧性能进行了综合测试,考察了不同质量分数的玉米秸秆木质素对改性环氧树脂性能的影响。结果表明:以固化体系的总质量为基准,在w(木质素)=0~7%的范围内,与未添加木质素的环氧树脂相比,随着木质素质量分数的增加,改性环氧树脂22℃下的黏度从1 220 m Pa·s增大到13 220 m Pa·s;改性环氧树脂固化物的弯曲强度随木质素质量分数的增加先升高后降低,在w(木质素)=3%时达到最大值83.2 MPa,但其冲击强度下降,由20.7 MPa降低为13.6 MPa;改性环氧树脂固化物的玻璃化转变温度(Tg)随木质素质量分数的增加而增加,w(木质素)=5%时Tg提高了4.8℃;改性环氧树脂固化物的热稳定性有所改善,w(木质素)=7%时热失重50%的温度提高13℃,同时木质素的加入能够改善环氧树脂的阻燃性能。     

电子封装用环氧树脂的增韧和提高耐热性研究

用α,ω 二氯聚二甲基硅氧烷(DPS)或α 氯聚二甲基硅氧烷(CPS)来改性普通双酚A环氧树脂(BPAER)和四溴双酚A环氧树脂(TBBPAER),目标是制备出一系列可用于电子封装的高韧性高耐热性的环氧基料。通过对固化物的冲击强度、拉伸强度、断裂伸长率和玻璃化转变温度(Tg)以及断裂面形态的测定,探讨了改性方法、有机硅组成与含量等对材料性能的影响。结果表明,当m(BPAER)∶m(DPS)=100∶10时,树脂固化物的冲击强度达到30 5kJ/m2,拉伸强度达46 95MPa,断裂伸长率达到60 23%,Tg达到141 3℃;分别比未改性BPAER提高了19 7kJ/m2,1 69MPa,54 29%以及5 9℃。而当m(TBBPAER)∶m(CPS)=100∶10时,固化物的冲击强度达到17 2kJ/m2,拉伸强度达39 89MPa,断裂伸长率达到5 60%,Tg达到147 0℃;分别比未改性TBBPAER提高了12 8kJ/m2,28 26MPa,4 29%以及7 9℃。     

有机硅改性环氧树脂的制备及其性能研究

利用三种乙氧基硅烷单体混合不完全水解合成含乙氧基的有机硅低聚物,使其与环氧树脂反应成功制备出有机硅改性环氧树脂。探讨了不同水解用水量的有机硅对改性树脂固化物冲击强度、弯曲强度和热稳定性的影响。结果表明,当水解用水量为完全水解用水量的0.5倍时,环氧树脂固化物的耐热性和韧性均有明显提高,冲击强度达14.07 kJ/m2,弯曲强度达26.73 MPa,50 %的质量热损失温度达424 ℃;比未改性的纯环氧树脂分别提高了10.23 kJ/m2,6.98 MPa和23 ℃。     

有机硅改性环氧树脂性能研究

采用RSN-0217有机硅树脂对128液态环氧树脂进行化学改性,调整有机硅树脂比例得到一系列无溶剂改性有机硅环氧树脂。环氧当量、IR、Tg分析结果表明有机硅树脂与128环氧树脂羟基发生接枝反应,环氧基得到保留,不影响树脂交联密度。热分解温度测试结果显示耐热性得到明显提高,RSN-0217有机硅树脂10%添加比例固化物80%失重温度为481. 2℃,比128环氧树脂高79. 8℃,冲击强度也比128环氧提升46. 9%。本文合成得到有机硅环氧树脂不含溶剂,可应用于无溶剂涂料、电子灌封等。     

有机硅改性环氧树脂的合成与性能

热熔法制备了系列聚甲基苯基硅氧烷(PMPS)改性环氧树脂,通过环氧值、红外光谱(IR)和凝胶色谱(GPC)分析表明,有机硅接枝到了环氧树脂上,且环氧基保持不变。探讨了改性方法、有机硅含量对改性树脂固化体系的微观形态、韧性及耐热性的影响。实验表明,当m(E-20)∶m(DC-3074)=7∶3时,化学改性树脂固化体系的韧性和耐热性能明显提高,玻璃化转变温度(Tg)为88.33℃,质量损失50%时的热分解温度(Td)为487.80℃,分别比物理改性环氧树脂提高了52.63℃和36.75℃,同时此改性树脂固化物还具有优良的涂膜性能。     

室温固化低黏度双酚F环氧树脂体系的研究

选择具有设计结构的固化剂和活性稀释剂,并研究其对体系性能的影响,确定了室温固化耐高温低黏度双酚F环氧树脂配方体系。该体系黏度低,凝胶时间较长,耐热性良好,力学性能优异。固化产物的T_g可达110℃以上,拉伸强度可达90 MPa,弯曲强度可达150 MPa。能够很好地适用于低温固化,中、高温使用的树脂基复合材料成型技术。     

活性稀释剂种类对环氧树脂体系性能的影响研究

采用丁基缩水甘油醚(660)、乙二醇二缩水甘油醚(669)和苯基缩水甘油醚(690)三种活性稀释剂对环氧树脂/甲基四氢邻苯二甲酸酐(MeTHPA)固化体系进行改性,研究了稀释剂对树脂胶液粘度及其固化物力学性能和电性能的影响。结果表明,当加入669和690稀释剂后,体系的介电性能基本不变,耐电弧性能提高,而660的加入会降低体系的介质损耗,对耐电弧性能影响很小。其中,当690的添加量为3%时,耐电弧达到94s,比纯树脂提高了22%;当添加量为3%～12%时,树脂固化物的拉伸强度稳定在45～55MPa之间。     

烯丙基酚氧树脂改性双马来酰亚胺树脂基体的研究

以新型烯丙基酚氧树脂作为BMI(双马来酰亚胺)树脂的改性剂,制备相应的改性树脂,并采用红外光谱(FT-IR)法跟踪了该改性树脂的固化反应过程;探讨了活性稀释剂D和后固化工艺等对该改性树脂的黏度、凝胶时间、力学性能和热性能等影响。结果表明:当n(活性稀释剂D):n(BMI)=10:100时,改性树脂的综合性能相对最好,其冲击强度为30.52 kJ/m²、弯曲强度为157.1 MPa和HDT(热变形温度)为224℃;加入适量的活性稀释剂D,可明显降低体系的黏度、提高改性树脂的韧性;后处理工艺可以明显提高改性树脂的耐热性,当后处理工艺为"220℃/2 h→240℃/2 h"时,改性树脂的HDT达到了314℃。     

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。