甲基丙烯酸锌补强氢化丁腈橡胶耐老化性能的研究

试验研究甲基丙烯酸锌（ZDMA）补强氢化丁腈橡胶（HNBR）热空气老化前后的物理性能和动态力学性能。结果表明:随着ZDMA用量的增大,HNBR胶料的t₁₀和t₉₀缩短,M_L和M_H增大,硫化胶的邵尔A型硬度和100%定伸应力增大,拉伸强度和拉断伸长率先增大后减小;经热空气老化后,随着老化时间的延长,HNBR硫化胶的邵尔A型硬度和100%定伸应力增大,拉伸强度和拉断伸长率减小;延长老化时间或增大ZDMA用量,HNBR硫化胶的储能模量和损耗模量增大,损耗因子峰值逐渐减小,损耗模量峰值和玻璃化温度逐渐向高温方向移动。     

碳酸钙改性PBAT的力学性能及结晶行为

以可生物降解塑料聚己二酸对苯二甲酸丁二酯(PBAT)为基体、工业级CaCO₃为填料,采用熔融共混制备PBAT/CaCO₃复合材料。探究CaCO₃含量对复合材料力学性能和结晶行为的影响,并且,筛选出综合力学性能较好的PBAT/CaCO₃复合材料。力学性能测试结果表明,添加少量CaCO₃(5%、10%)后,PBAT/CaCO₃复合材料的拉伸强度有小幅降低,断裂伸长率和冲击强度增大;当CaCO₃含量达到20%及以上时,复合材料的拉伸强度、断裂伸长率和冲击强度均显著降低,与纯PBAT相比,最大降幅分别为36.40%、60.00%、87.42%;弯曲强度、弯曲模量、拉伸模量均随CaCO₃含量的增加而增大。DSC结果表明,添加CaCO₃后,PBAT/CaCO₃复合材料的熔融和结晶温度均显著提高,结晶度降低,透明性降低。     

热氧老化对特种氟橡胶交联结构及力学性能的影响

采用加速老化实验方法对特种氟橡胶密封材料的热氧老化性能进行了研究,获得了不同老化温度及老化时间对特种氟橡胶力学性能和交联结构的影响规律。研究结果表明,氟橡胶在热空气中老化时随老化温度的升高和老化时间的延长,材料的拉伸强度、硬度降低,100%定伸应力先增加后减小,拉断伸长率先减小后增大,回弹性和压缩永久变形增大。材料的交联密度先增加后减少,表明氟橡胶在热氧老化初期以交联为主,在老化后期以降解为主。     

动态热机械仪分析氟橡胶的热氧老化性能

通过动态热机械分析仪(DMA)可测定氟橡胶在周期性变化的应力(或应变)下所表现出的模量或损耗,由此反映橡胶内部的结构变化。选择市售工艺性质稳定的二元氟橡胶为样品,分别在100℃、120℃、140℃、160℃、180℃下进行老化处理,用DMA测定其损耗模量、储能模量、应力松弛及应变恢复性质。研究结果表明:随着老化温度升高,样品胶片使用温区变窄,损耗增大,回弹性能变差,应力松弛性能变差,应变恢复量降低。试验预测出160℃以下为二元氟橡胶长期使用的最佳环境温区。     

高温内压环境下聚乙烯燃气管道老化性能评价研究

将一批聚乙烯燃气管道试样置于80 ℃、1.1 MPa水浴环境下进行老化试验，老化时间分别为0、165、500、1 000 h，并通过差示扫描量热法（DSC）、热失重分析（TG）、傅里叶变换红外光谱分析（FTIR）和拉伸试验分别测试各老化试样对应的氧化诱导时间（等温OIT）、热分解温度（T_s）、官能团组成和断裂伸长率（ε），模拟分析高温内压环境下聚乙烯管道的老化性能变化规律。DSC、TG和拉伸试验结果显示，随着老化时间增加，聚乙烯管道的等温OIT、T_s和ε都逐渐降低，老化程度逐渐增加，并且管内壁的老化速率明显大于外壁；FTIR结果显示，随着老化时间增加，聚乙烯管材料的官能团谱图中1 720 cm^-1和3 400 cm^-1处分别出现了C=O和O—H的振荡峰，进一步证实了聚乙烯管材料分子链中引入了氧化反应产物。     

物理老化对非晶态PET结构、性能以及结晶的影响

采用密度、DSC、应力—应变测量、溶剂诱导结晶和声速测定等方法研究了物理老化对非晶态PET膜和纤维结构与性能的影响.研究结果表明,非晶态PET经物理老化后DSC曲线上的Tg增加,并出现吸热峰,热结晶变慢,溶剂诱导结晶和溶剂扩散速率变慢,初始模量和屈服应力增加,从物理老化引起PET中凝聚缠结增加这一结构变化的角度对上述实验现象进行了解释.     

氟橡胶耐热氧老化性能的研究

研究炭黑N330/N990用量比对过氧化物硫化体系氟橡胶物理性能和耐热氧老化性能的影响,并与双酚A硫化体系氟橡胶进行比较。结果表明:随着炭黑N330/N990用量比增大,过氧化物硫化体系氟橡胶的物理性能和耐热氧老化性能提高,压缩永久变形明显减小;当炭黑N330/N990用量比较大时,氟橡胶的物理性能变化不大;与双酚A硫化体系氟橡胶相比,过氧化物硫化体系氟橡胶的硬度和定伸应力较小,拉伸强度和拉断伸长率较大,耐热氧老化性能较好。     

含氟硅酸的镀液成分对镀铬板性能的影响

针对两步法镀铬工艺,采用电化学实验、X射线光电子能谱(XPS)以及扫描电子显微镜(SEM)等检测手段,就镀液中H₂Si F₆与CrO₃的含量对镀铬液特性,镀层表面氧化铬和金属铬含量、孔隙率,以及镀铬板电化学性能的影响进行了分析。结果表明,CrO₃含量对镀液电导率有明显影响,镀层内铬氧化物的含量以及镀液的pH主要由镀液内H₂Si F₆的含量所控制。第一步镀铬时,在镀液中H₂Si F₆为1.75 g/L、CrO₃为150 g/L、H₂SO₄为0.7 g/L的条件下,镀铬板的腐蚀电位较正,腐蚀电流密度较小;在第二步镀铬中,当H₂Si F₆为0.30 g/L、CrO₃为34 g/L、H₂SO₄为0.35 g/L时,镀铬板腐蚀电位较正,腐蚀电流密度较...     

考虑材料拉压模量不同及应变软化的厚壁圆筒解析解

基于三剪应力统一强度理论和弹脆塑性模型,同时考虑材料拉压模量不同及应变软化、中间主应力效应,推导了单层厚壁圆筒均匀内压与塑性软化区半径的关系、双层厚壁圆筒均匀内压作用下的弹脆塑性极限承载力,分析了参数b、c、半径比r_b/r_a、材料的拉压模量系数λ对双层组合厚壁圆筒的影响特性。通过算例分析表明:双层组合厚壁圆筒弹性极限承载力P_emax随b的增大而增大,随c的增大而减小,随材料的拉压模量系数λ增大而减小;对理想弹塑性材料,脆塑性极限承载力P_u1随b的增大而增大,随c的增大而减小,随半径比r_b/r_a的增大而增大,与材料的拉压模量系数λ无关;对其它材料,脆塑性极限承载力P_u3随b的增大而增大,随c的增大而减小,随材料的拉压模量系数λ增大而减小。三剪应力统一强度理论解包含了Mohr-Coulomb解及双剪统一强度理论解,还能得到一系列化的新解,对单层和双层组合厚壁圆筒的设计及应用具有参考价值。     

铜浆料用ZnO-B2O3-SiO2-BaO玻璃的结构和性能

本文以铜浆料用ZnO-B₂O₃-SiO₂-BaO玻璃为对象，通过X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、拉曼光谱(Raman)、核磁共振铝谱(²⁷Al NMR)、差示扫描量热(DSC)和扫描电子显微镜(SEM)等表征方法，研究了ZnO含量对其结构和性能的影响。结果表明，随着ZnO含量的增加，玻璃试样中BO/NBO(摩尔比)、玻璃试样的平均桥氧数和[ZnO₄]/[ZnO₆]摩尔比均先增大后减小，[BO₄]/[BO₃]摩尔比增大，[AlO₆]和[AlO₅]摩尔占比增大，[AlO₄]摩尔占比降低。玻璃试样网络结构连接度整体先致密后疏松，且当ZnO的质量分数为36%时玻璃试样网络结构最为致密。当ZnO质量分数从32%增加到42%时，玻璃试样的DSC曲线中玻璃化转变温度T_g、起始烧结温度T     

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.     

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.     

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。     

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.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.