可化学回收的生物基环氧玻璃体

采用生物基缩水甘油醚季戊四醇双缩香草醛环氧树脂（DEPVD）为原料，经商用二苯二硫醚胺固化剂（AFD）固化得到生物基环氧玻璃体（DEPVD-AFD）。利用核磁共振氢谱（1H-NMR）对DEPVD的结构进行了表征。通过红外光谱（FTIR）、示差扫描量热仪（DSC）、热重分析仪（TGA）、拉伸测试机、降解回收实验等手段对环氧树脂的固化过程和综合性能进行了表征。结果表明，树脂材料具有较好的力学性能、热稳定性及降解性能，其玻璃化转变温度为143℃，拉伸强度为87.0 MPa，杨氏模量约为2 300 MPa,10%热失重温度为323℃。降解回收实验的结果表明，固化剂中含有的螺环缩醛结构赋予了环氧树脂可降解的特性。DEPVD-AFD能在H+浓度为0.1 mol/L的1,4-二氧六环溶液中完全降解（处理温度75℃，时间4 h），由于降解产物具有显著的溶解度差异，含有二苯二硫醚结构的高价值中间产物（DSS）可以通过水洗的方式进行简单高效的回收，DSS的FTIR和1H-NMR结果表明此中间产物具有明确的化学结构和较高的纯度，这种简单高效的回收方式有望为环氧玻璃体的化学回收铺平道路。     

耐高温拉挤环氧树脂及其复合材料性能研究

本文研究了改性多元缩水甘油胺型耐高温环氧树脂的固化动力学,分析了该树脂体系的浇注体性能,制备了碳纤维拉挤复合材料,并通过热机械分析(DMTA)考察了树脂浇注体及其复合材料的动态热机械性能.结果表明,树脂体系的凝胶化温度与固化温度相差较小,固化反应放热集中,适合于快速拉挤成型;其复合材料具有优良的耐高温性能,玻璃化温度(Tg)达到210℃以上.     

二缩水甘油二甘醇胺封端聚氨酯/环氧树脂复合体系的热力学性能研究

以二缩水甘油二甘醇胺(DGDGA)作为端-NCO型聚氨酯(PU)预聚体的封端剂,合成出了具有高反应活性的二缩水甘油二甘醇胺封端的聚氨酯(DGDGAPU)。并用其改性环氧树脂,得到了固化速度匹配、相容性好的聚氨酯/环氧树脂复合体系。采用红外光谱(FT-IR)法对其结构进行表征,采用TG研究其热性能,通过冲击、压缩等方法研究其力学性能,并用SEM分析发现其形成了交联紧密的DGDGAPU/EP网络。结果表明,在加入50%环氧树脂时体系力学性能最佳。     

碳纤维增强树脂基复合材料性能的研究

以不同含量的二乙烯三胺(DETA)固化的环氧树脂为基体,制备了碳纤维增强树脂基复合材料。通过扫描电镜和红外光谱分析了T-300型碳纤维表面形貌和基团组成。通过拉伸实验、冲击实验对复合材料的力学性能进行了表征;通过紫外老化实验对复合材料的耐候性进行了表征;通过扫描电镜和热重分析对复合材料的断面形貌和耐热性进行了表征。结果表明:碳纤维增强树脂基复合材料具有良好的耐候性、力学性能、而且还具有质量轻、高比强度等一系列优异的性能。     

压力法回收废旧碳纤维/环氧树脂复合材料

采用醋酸水溶液对碳纤维/环氧树脂复合材料进行初步处理,然后以过氧化氢水溶液和丙酮混合溶液再次处理得到可分离的碳纤维和降解液。采用扫描电镜、热重分析、力学性能测试,红外及气相色谱-质谱联用分析研究了压力法降解废旧碳纤维/环氧树脂复合材料的反应条件和机理。结果表明,环氧树脂分解的主要机理为酯键断裂,以体积分数70%的醋酸水溶液180℃下浸泡2 h,再用过氧化氢和丙酮混合溶液在120℃,1.2 MPa下加热2 h,碳纤维/环氧树脂的降解效率高,回收的碳纤维表面没有明显缺陷并仍具有良好的力学性能。     

氟化硅氧烷改性环氧树脂的制备与性能

首先,以全氟(2-甲基-3-氧杂己基)氟化物(六氟环氧丙烷二聚体)和N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷(KH792)为原料制备一种氟化硅氧烷,用FTIR和1HNMR表征其结构.然后,将氟化硅氧烷与聚醚胺共同固化环氧树脂DGEBA(双酚A型二缩水甘油醚),测试了改性环氧树脂复合材料的性能.结果表明,与未改性环氧树脂相比,加入氟化硅氧烷使含氟量1％(以DGEBA质量计)改性环氧树脂复合材料的表面静态水接触角由72.0°增至103.2°,表面能由(42.08±2.17)mN/m降至(20.55±1.45)mN/m,40 d吸水率由1.75％降至1.38％,有效提高了材料的疏水性;介电常数由3.83降低至3.63;材料热分解5％温度由339℃升高至347℃;拉伸及弯曲力学性能分别提高了8.5％及7.7％.含氟量为1％时,改性环氧树脂复合材料的综合性能最佳,差式量热扫描和动态力学性能测试结果表明,少量改性剂可以促进环氧树脂的固化反应,提高固化度和交联密度;当氟化硅氧烷添加量增加时,材料内部发生显著的微相分离并导致性能逐渐下降.     

氧化石墨及硅烷偶联剂改性氧化石墨填充环氧树脂复合材料性能研究

采用改进Hummers法制得氧化石墨,采用硅烷偶联剂γ-缩水甘油醚氧丙基三甲氧基硅烷(GPTS)进行改性,用TGA、XRD、XPS表征出氧化石墨和改性氧化石墨的形态和性质。通过超声共混制得其复合材料,测试得到其固化性能、导热性能和力学性能。结果表明:制备的氧化石墨对环氧树脂固化有促进作用,改性氧化石墨对环氧树脂固化并无明显影响。硅烷偶联剂改性氧化石墨作为分散相得到的复合材料的导热性能、弯曲强度和拉伸断裂强度相对于氧化石墨填充复合材料有所提高。     

乙醇木质素改性环氧树脂/聚醚胺复合材料研究

以N,N-二甲基甲酰胺(DMF)为溶剂,采用溶液共混和机械搅拌相结合的方法将乙醇木质素(EL)添加到环氧树脂中,再以聚醚胺固化制备得到环氧复合材料。通过拉伸和冲击性能测试、扫描电镜和示差量热分析研究了木质素添加量对复合材料力学性能、形貌结构和固化反应的影响。结果表明:木质素在DMF中具有很好的溶解性,可以得到均一的木质素/环氧树脂复合体系。木质素的加入对环氧树脂/聚醚胺体系固化反应具有一定的促进作用。与纯环氧树脂体系相比,木质素的质量分数为1.5%时,复合材料的拉伸强度、断裂伸长率和冲击强度分别提高了3.1%,14.7%和13.5%。     

室温固化湿法缠绕用环氧树脂体系研究

采用双酚A环氧树脂CYD-128,苯基缩水甘油醚690,环己二醇二缩水甘油醚180,自制聚氨酯预聚体增韧剂Z1和硅烷偶联剂KH550为A组分,改性脂环胺HD、改性聚醚胺2310和改性脂肪胺706为B组分制备了一种室温固化用于湿法缠绕的环氧树脂体系。测试了体系的粘温特性,固化物玻璃化转变温度及其力学性能,制备了单向复合材料,并对复合材料容器进行了压力性能测试。结果表明,该环氧树脂体系具有适宜的粘度和足够的适用期,浇铸体力学性能优异,能够满足湿法缠绕工艺要求,容器性能达到中温固化环氧树脂体系的水平。     

环氧树脂改性双马来酰亚胺/氰酸酯树脂固化工艺研究

采用差示扫描量热(DSC)法和红外光谱(FT-IR)法对缩水甘油胺型环氧树脂(AG-80)与脂环族缩水甘油酯型环氧树脂(TDE-85)共同改性双马来酰亚胺(BMI)/氰酸酯树脂(CE)的固化反应历程进行了研究,并按照Kissinger和Crane法计算出该改性树脂体系固化反应的动力学参数。结果表明:改性树脂体系的固化反应表观活化能为68.11 kJ/mol,固化反应级数为0.860(接近于1级反应);环氧树脂(EP)可促进CE固化,当固化工艺条件为"150℃/3 h→180℃/2 h"时,改性树脂体系可以固化完全。     

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。