水中固化环氧胶粘剂的研究

以E-44环氧树脂为主剂，以低分子聚酰胺和酚醛胺混合物(质量比为1：1)为固化剂．胶中还包含活性稀释剂、偶联剂、填料等辅助成分，制成双组分水下胶粘剂。该胶在25℃水中72h即可固化．剪切强度可达6．5MPa。该胶使用方便，性能优良，已实现工业化生产。     

非异氰酸酯聚氨酯改性环氧树脂胶粘剂的研究

用聚酰胺和环氧树脂、三环碳酸酯进行反应,制备了一种非异氰酸酯聚氨酯改性环氧树脂胶粘剂,胶粘剂固化物兼具聚氨酯和环氧树脂的性能,有合适的强度和韧性。胶粘剂固化物本体拉伸强度为32.0 MPa,拉断伸长率为3.7%。粘接复合材料拉剪强度为9~17 MPa,粘接金属拉剪强度为16~21 MPa。该胶粘剂可在-150℃(长时间)到150℃(短时间)使用。胶粘剂适用期3h以上,可25~30℃/3 d固化,适合大型复合材料粘接。实验结果表明,固化时聚酰胺651的氨基和环氧树脂的环氧基、三环碳酸酯的环碳酸酯基发生了反应,2种反应速度接近,相容性较好,胶粘剂固化物形成了多种三维互穿网络结构。     

新型增韧改性环氧胶粘剂

天津城建学院与河北大学合作攻关，以丁腈-40液体橡胶为主料，对E-44双酚A环氧树脂／低分子质量聚酰胺树脂固化体系进行了增韧改性，研制出新型改性环氧树脂胶粘剂，该剂可以在室温下24h固化，室温剪切强度最高可达22．4MPa，     

新型增韧改性环氧胶粘剂问世

天津城建学院与河北大学联合攻关，采用液体丁腈-40橡胶对环氧树脂进行增韧，研制出可室温较快固化、剪切强度较高的改性环氧胶粘剂。环氧树脂与液体丁腈橡胶的最佳质量比为10：1，制得的结构胶粘剂室温24h固化后，具有良好的力学性能，室温剪切强度高达22．4MPa，一般的丁腈橡胶虽然也能增韧环氧树脂，但改性后的粘接强度提高不大。端羧基液体丁腈橡胶（CTBN）对环氧树脂增韧效果很好，可是原料价格太高，受到制约。而采用液体丁腈-40橡胶，对E-44环氧树脂／低分子聚酰胺体系进行增韧，可得到室温固化、剪切强度较高的改性环氧胶粘剂。     

室温固化无溶剂岩芯胶粘剂的制备及性能

选用低黏度的双酚A型环氧树脂E-44、E-51与酚醛改性胺室温固化剂,开发了一种室温固化无溶剂岩芯胶粘剂。探究主体胶粘剂配方,并研究各助剂及用量对主体胶粘剂性能的影响。研究结果表明:在m(E-44):m(E-51):m(酚醛改性胺)=70:30:100的配方下,主体胶粘剂配方的综合性能较好;m(E-44):m(E-51):m(固化剂):m(增韧剂DOP):m(偶联剂KH-550):m(硅微粉):m(碳酸钙)=70:30:100:15:3:4:12时,该胶粘剂体系剪切强度最大,达到了16.10 MPa。选取该最大剪切强度胶粘固化体系进行其他测试,得到胶粘剂体系的接触角达到了79.4°;热失重结果显示,其在200℃之后才开始分解,耐热性较好。另外,该配方的凝胶时间及流平性均可满足实际操作要求,固化物不会造成岩芯污染,为该胶粘剂在岩芯上的应用提供科学依据。     

多孔材料用耐高温软质环氧胶粘剂的制备与性能

为实现有机硅多孔材料的软性粘接,以α,ω-二羟基聚二甲基硅氧烷(聚硅氧烷)和CTBN(端羧基液体丁腈橡胶)对双酚A型E-44环氧树脂进行化学改性,制备了一种新型的多孔材料用耐高温软质胶粘剂。研究结果表明:当m(聚硅氧烷)∶m(E-44)=1∶8且m(CTBN)∶m(聚硅氧烷改性环氧树脂)=1∶4时,胶粘剂剪切强度可达40.8 MPa,拉伸强度可达0.29 MPa,Td5%高达240℃,耐腐蚀性良好。在保证粘接强度的同时,该胶粘剂可使粘接处达到与基体相似的韧性与硬度,提高了长期使用性。     

铅酸蓄电池用密封胶的配比对性能的影响

以改性环氧树脂(EP)与改性芳香胺固化剂为原料制备铅酸蓄电池极柱灌封用密封胶,着重研究了改性EP与固化剂的配比对胶粘剂性能的影响。实验结果表明,改性EP与固化剂配比对胶粘剂的初步固化时间、热变形温度、剪切强度和拉伸强度的影响显著;3种配比的胶粘剂耐酸碱性能均较好;当m(改性EP)∶m(固化剂)=100∶50时胶粘剂的综合性能最优,其初步固化时间为6 h、热变形温度为97℃、拉伸强度为72 MPa、剪切强度为3.56 MPa且对ABS的粘接达到材料破坏的程度。该胶粘剂室温固化具有一定的适用期,并具有良好的粘接性能、耐久性能和耐酸性能,可以满足蓄电池极柱灌封和粘接的技术要求。     

均苯四甲酸酐固化聚丁二烯环氧树脂胶粘剂的研究

采用均苯四甲酸酐(PMDA)固化聚丁二烯环氧树脂(ELPB),制备了ELPB/PMDA耐高温胶粘剂,并使用傅里叶红外光谱仪(FT-IR)、热重分析仪(TGA)、拉力机和数码显微镜对固化产物的性能进行了表征。实验结果表明,在200℃固化2h的条件下,PMDA可以对ELPB成功地固化;固化后的胶粘剂具有良好的耐热性能,其失重3%时的分解温度为300℃;该胶粘剂对铝/铝合金的粘接强度达到15MPa;剪切破坏是以内聚破坏为主的混合破坏,表明该胶粘剂对金属有较好的粘接性能。     

高铁车厢地板革胶粘剂的制备和性能研究

以改性环氧树脂、低分子聚酰胺为主要原料,制备了一种双组分室温固化胶粘剂。研究了促进剂对胶粘剂可操作时间的影响,测试了胶粘剂应用的各项性能。研究结果表明制备的胶粘剂具有优异的综合性能。配胶适用期为180 min,固化物韧性好,断裂伸长率为16.5%,粘接强度为铝/铝16MPa,粘接地板革达到内聚破坏,耐水性、环保性、防火性能均满足高铁车厢对胶粘剂材料的要求。     

聚醚胺固化环氧树脂胶粘剂的研究

以聚醚胺D-230为固化剂,研究了多官能度环氧树脂和硫酸钙晶须的加入对环氧树脂胶粘剂粘接性能的影响。研究结果表明,多官能度环氧树脂和改性硫酸钙晶须的加入,很好地改善了环氧树脂胶粘剂的高温性能;当环氧树脂m(E-51)∶m(F-51)∶m(AG-80)=3∶3∶2、改性硫酸钙晶须为树脂总质量的10%时,体系的粘接性能最佳,室温和100℃剪切强度分别为25.91MPa和6.11MPa,室温剥离强度可达5.26kN/m。     

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。