纳米Fe3O4/环氧树脂基复合材料制备及导热性研究

选用水热法制备Fe3O4纳米粒子为填料,通过直接混合分散法制备了纳米Fe3O4/环氧树脂基复合材料。测试分析了Fe3O4纳米粒子的形貌、结构和磁性能。并且复合材料的导热系数也被测定,结果表明,随着粒子填充体积增加,复合材料导热系数增大。当添加28.47%的纳米Fe3O4粒子时,复合材料导热系数达到0.409 W/（m.k）,是纯环氧树脂E-44的2.54倍。通过对Y.Agari导热模型分析计算,得到了能对该复合材料导热系数进行较好预测的方程。     

Fe_3O_4@rGO复合磁性粒子对聚氨酯弹性体复合材料性能的影响

将3种不同的Fe3O4@还原氧化石墨烯(rGO)–四氢呋喃(THF)复合磁性粒子分散液分别与聚氨酯(PUR)弹性体进行原位聚合制备3种PUR弹性体/Fe3O4@rGO磁性复合材料,并对其组分和分散状态进行了表征,系统研究了Fe3O4@rGO复合磁性粒子对PUR弹性体磁性能、热性能和力学性能的影响。结果表明,仅掺入质量分数为0.5%的Fe3O4@rGO复合磁性粒子可以显著提高PUR弹性体的性能。随着Fe3O4@rGO复合磁性粒子中rGO含量的增加,PUR弹性体复合材料的饱和磁化强度逐渐下降,热稳定性和力学性能均逐渐提高。当复合磁性粒子中rGO质量分数为60%时,复合材料的力学性能最佳,拉伸强度、断裂伸长率和拉伸弹性模量分别为35.31MPa,438.90%和86.42MPa,玻璃化转变温度、最大损耗因子和在–60℃时的储能模量分别达10.64℃,0.41和3805.84MPa。此外,扫描电子显微镜观察发现,Fe3O4@rGO复合磁性粒子在基体中具有良好的分散性。     

Fe2O3/PA6复合材料的制备及性能研究

将通过液压-热晶法合成的纳米Fe2O3粒子加入到聚合反应体系中进行原位聚合,制得纳米Fe2O3/PA6复合材料。通过扫描电镜研究了纳米Fe2O3在PA6基体中的分散情况,将复合材料挤压成直径为1mm的细线,测试了其力学性能和热学性能。结果表明,纳米Fe2O3在基体中分散均匀,当纳米Fe2O3质量分数为16.7%时,复合材料的最大失重速率温度比纯PA6提高了16.0℃,热稳定性得到提高,拉伸强度和拉伸模量比纯PA6分别提高了27.78%和109%。     

聚丙烯/四氧化三铁纳米复合材料的制备、表征及磁性能研究

采用固态高速搅拌预混-熔融密炼过程制备了磁性聚丙烯(PP)/四氧化三铁(Fe3O4)纳米复合材料,并分别利用扫描电镜(SEM)、X射线衍射(XRD)、示差扫描量热仪(DSC)、热失重分析仪(TGA)和振动样品磁强计(VSM)对获得的复合材料的形貌、结构及磁性能进行了表征。结果显示:Fe3O4纳米粒子质量分数为5%时在聚合物基体中分散良好,基本呈单颗粒分散;随着Fe3O4含量的增加,粒子在PP基体中团聚程度加剧。Fe3O4和PP在复合材料中保持了各自的晶相结构,但是Fe3O4的加入降低了PP的结晶程度。同时,Fe3O4的加入提高了PP的热稳定性。振动样品磁强计(VSM)的结果表明:复合材料的饱和磁化强度(Ms)随Fe3O4含量的增加而增加,并呈线性的依赖关系;矫顽力(Hc)和剩余磁化强度(Mr)均很小,所制得的磁性纳米复合材料近似呈超顺磁性;该研究为磁性高分子纳米复合材料的制备提供了一种简单易行,Fe3O4纳米粒子在聚合物基体中良好分散,并且可以大批量生产磁性纳米复合材料的方法,并可能促进PP/Fe3O4纳米复合材料在电磁屏蔽和微波吸收等领域的应用。     

纳米SiO2/EP复合材料的制备与性能研究

环氧树脂(EP)固化后交联密度高,呈三维网状结构,存在质脆、耐热性和耐冲击性较差等缺陷,从而限制了其应用范围。通过在环氧树脂中添加纳米Si O2,可以起到增强、增韧和提高热稳定性的作用。本文采用物理共混方法浇铸成型制备纳米Si O2/EP复合材料,并用偶联剂KH-550对纳米Si O2进行表面改性。主要研究纳米Si O2粒子的表面处理、分散方法和粒子添加量对纳米Si O2/EP复合材料力学性能的影响。结果表明:纳米Si O2的加入可以提高Si O2/EP复合材料的力学性能,其中采用偶联剂处理与超声波分散结合时纳米Si O2在环氧树脂基体中的分散效果最佳,当纳米Si O2粒子添加量为3%时,复合材料的的综合性能最佳。     

纳米Fe3O4用量对纳米Fe3O4/NR复合材料性能影响的研究

采用乳液共凝法制备纳米Fe3O4/天然橡胶（NR）复合材料,所用纳米Fe3O4是用化学共沉淀法制备的纳米Fe3O4乳液。研究了纳米Fe3O4用量对纳米Fe3O4/NR复合材料的力学性能、热稳定性、加工性能的影响。结果表明：纳米Fe3O4的用量对纳米Fe3O4/NR复合材料的性能有较大的影响。在NR中加入纳米Fe3O4,混炼胶的G′较高,tanδ较小,提高了复合材料的力学性能和热稳定性。当纳米Fe3O4的质量分数为15%时,纳米Fe3O4/NR复合材料的综合性能较好。     

杜仲胶/聚乳酸形状记忆热塑性硫化胶的制备及性能

将生物基高分子材料杜仲胶（EUG）和聚乳酸（PLA）通过动态硫化技术制备了具有形状记忆性能的热塑性硫化胶（EUG/PLA TPV）。通过扫描电子显微镜、差示扫描量热、动态力学和力学性能测试及热机械循环分析等手段分别考察了EUG/PLA TPV的微观形貌、相容性、热性能、动态力学和力学性能及形状记忆性能。结果表明,增容剂腰果酚有效改善了EUG相与PLA相之间的相容性,从而提高了EUG/PLA TPV的力学性能。当橡塑质量比为5/5时,拉伸强度为10.5 MPa,扯断伸长率达到286%,是纯PLA的约48倍。EUG/PLA TPV具备特殊的双连续相结构,可以赋予其良好的形状记忆性能,形状固定率最高达到93%左右,形状回复率最高达到98%左右。     

苯乙烯丙烯酸正丁酯共聚物/Fe3O4复合材料的制备与表征

采用原位聚合法制备了苯乙烯丙烯酸正丁酯共聚物（PSb）/四氧化三铁（Fe3O4）纳米复合材料,并通过傅里叶变换红外光谱仪、透射电子显微镜、X射线衍射仪、综合物理特性测量系统对该复合材料的结构与性能进行了表征。结果表明：Fe3O4纳米粒子直径约9 nm,同时能较均匀地分散在PSb中且无明显团聚;该复合材料具有良好的超顺磁性;XRD图谱中Fe3O4特征峰随着复合材料中Fe3O4含量的增加而逐渐增强;同时Fe3O4纳米粒子的加入提高了PSb的热稳定性。     

纳米SiO2增强增韧聚氯乙烯复合材料的研究

采用超声波，振磨等方法对纳米SiO2粒子进行表面处理。通过熔融共混的方法制备了PVC/SiO2纳米复合材料，研究了纳米粒子对PVC的增强，增韧效果。研究结果表明；通过超声波，振磨等方法对纳米粒子进行表面处理。可以促进纳米粒子在基体中的均匀分散，大幅度提高复合材料的强度和韧性；纳米SiO2的添加量为3%时，复合材料的综合力学性能最好，其拉伸强度，冲击强度和杨氏模量均有较大的提高。     

纳米Si_3N_4/ACM复合材料的力学性能和硫化性能研究

采用大分子表面处理剂LMPB-g-KH570对纳米Si_3N_4表面进行修饰。利用共混技术制备了纳米Si_3N_4/ACM复合材料。利用RPA-8000、SEM、TEM等测试技术,对纳米复合材料的微观结构和性能进行了分析和评价。结果表明,大分子表面改性剂能有效改善复合材料的微观界面结构,促进纳米Si_3N_4在橡胶基体中的有效分散,橡胶硫化性能得到改善,力学性能得到提高。添加2.0份改性纳米Si_3N_4/ACM复合材料,胶料正硫化时间减少38 s,拉伸强度提高24.8%,撕裂强度提高3.39%。     

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。