聚丙烯蜡固-固相变材料的制备与工艺优化

针对聚丙烯蜡相变材料难以乳化分散、离子交联定型的问题,利用聚丙烯酸（PAA）羧基的亲水性,易离子化特性,设计了低聚合度聚丙烯酸（PAA）接枝聚丙烯蜡,以自乳化方法制备聚丙烯蜡乳液,通过常温离子交联,在水介质中、短周期内制备了聚丙烯蜡固-固相变材料（PPW SS-PCMs）。首先利用红外光谱仪、核磁共振波谱仪、扫描电子显微镜分析测试,探讨了丙烯酸的浓度及瞬时浓度对聚丙烯蜡（PPW）接枝产物自乳化能力的影响。然后,利用偏光显微镜、X射线衍射仪、差示扫描量热仪、热重分析仪对PPW接枝产物及PPW SS-PCMs的结晶性能、热稳定性做了测试和分析。结果表明：随着丙烯酸（AA）质量占比升高,定型相变材料的相变焓随AA含量的提升而下降。在一定范围内,通过提高AA瞬时浓度能提高改性PPW的自乳化能力,减少定型组分添加量。当AA、PPW、BPO质量比为0.36∶1∶0.05及滴加速率为9mL/min时,所制备的PPW SS-PCMs的结晶温度为52.46℃,结晶焓为-53.61J/g,储能效率为81.26%,具有较好的热稳定性。     

测试速率对PEG/GO定型相变材料熔融和结晶性能的影响

以聚乙二醇/氧化石墨烯(PEG/GO)定型相变材料为测试样品,采用差示扫描量热法(DSC)对其熔融、结晶性能进行了表征,研究了测试速率(即升/降温速率)对该相变材料熔融、结晶温度和热焓的影响。结果表明:随着降温速率的增加,PEG/GO相变材料的结晶温度逐渐降低;随着升温速率的增加,材料的熔融温度逐渐提升;测试速率越高,焓值越小;随着GO加入量的增加,升降温时的焓值均呈现降低的趋势;相同GO含量的PEG/GO定型相变材料,其熔融焓总是大于同等测试速率下得到的结晶焓,而且测试速率越快,差值越大;在相同测试速率下,GO的添加量基本不会对PEG/GO相变材料的熔融、结晶温度产生影响。     

定型相变材料对磷酸钾镁水泥性能的影响

利用实验室制备的癸酸/膨胀石墨定型相变材料、月桂酸/膨胀石墨定型相变材料和石蜡/膨胀石墨定型相变材料对磷酸钾镁水泥(MKPC)水化温升进行调控,同时研究了定型相变材料对MKPC水泥工作性能、水化热和强度的影响。结果表明:掺入癸酸/膨胀石墨定型相变材料、月桂酸/膨胀石墨定型相变材料后,MKPC的水化过程发生变化,磷酸钾镁水泥的性能改变:凝结时间缩短,流动度减小,水化温峰T_(max)和水化热降低,但强度有较大幅度减小。掺入石蜡/膨胀石墨定型相变材料后,MKPC水化温峰T_(max)随其掺量增加呈规律性降低。较癸酸和月桂酸,石蜡对MKPC水化过程影响较小,石蜡/膨胀石墨定型相变材料的MKPC工作性能更优。     

PEG、白炭黑复合相变储能材料的制备与性能研究

为拓宽相变储能材料的应用范围,以聚乙二醇400(PEG-400)为相变囊心材料,气相法二氧化硅(俗称白炭黑)为载体,采用囊壁溶液包裹制备了一种微胶囊定型相变材料.通过DSC、TGA、SEM试验对复合定形相变材料的性能和结构进行测试.结果表明:聚乙二醇与白炭黑的质量比为5:3、囊壁材料质量分数为8.5％、定型相变材料与囊壁溶液质量比在1:0.45和1:0.55之间时,制备的相变材料性能最优;制备的两种微胶囊定型相变材料的相变温度为-1.34、-2.19℃,相变焓为54.7、52.83 J·g-1;复合定型相变材料在366.38、384.13℃以内质量损失较小,热稳定性良好;微胶囊定型相变材料定形效果和热稳定性良好.     

太阳盐/钢渣定型复合相变储热材料的制备与性能研究

全球范围内的能源短缺和环境污染问题迫使人们积极开发可再生新能源。储热技术是解决新能源不稳定性问题的关键技术。相变材料是重要的储热介质之一。熔盐相变材料因其储热密度高,可操作温度范围广的优势,成为储热材料领域研究的热点。为解决熔盐液相易泄漏、低导热和高成本的问题,选择钢渣为基体材料,制备了太阳盐/钢渣定型复合相变储热材料,并通过扫描电子显微镜(SEM),热重–差示扫描量热法(TG–DSC),闪射法导热仪(LFA)和X射线衍射仪(XRD)对复合材料的微观结构、热性能和化学相容性进行了测试与表征。结果表明,钢渣与熔盐质量比5:5的复合材料定型效果最优。复合材料结构紧密;钢渣与熔盐化学相容性良好;复合材料潜热为64.0 kJ/kg,100~500℃内储热密度为945 kJ/kg,热导率高达2.23 W/(m?K)。太阳盐/钢渣复合相变储热材料不仅有利于储热技术的大规模应用,而且为钢铁工业废弃物回收利用提供了良好的参考,对节约资源、保护环境以及提高经济效益具有重要的意义。     

膨胀石墨基定型相变材料的性能研究

采用熔融共混法制备了癸酸/膨胀石墨定型相变材料(DA/EG-PCMs)、月桂酸/膨胀石墨定型相变材料(LA/EG-PCMs)和石蜡/膨胀石墨定型相变材料(PA/EG-PCMs),利用接触角测量仪、FT-IR、DSC、TG-DSC和热渗出实验分别对三种膨胀石墨基定型相变材料的亲疏水性、特征基团、热性能、热稳定性和耐久性进行表征。结果表明:膨胀石墨能很好的将癸酸、月桂酸和石蜡吸附住,三种相变材料与膨胀石墨之间仅存在物理结合作用。DA/EG-PCMs和LA/EG-PCMs都表现出亲水的特性,PA/EG-PCMs疏水。在膨胀石墨的高导热网络结构包覆下,三种膨胀石墨基定型相变材料相变温度提前,耐久性提高,DA/EG-PCMs与LA/EG-PCMs的热稳定降低,PA/EG-PCMs热稳定提高。     

碳气凝胶基复合相变材料的制备及其导热性能研究

以聚乙二醇(PEG)为相变材料,通过添加碳气凝胶,采用熔融共混和真空浸渍的方式制备了导热增强型相变复合材料。采用扫描电子显微镜、热常数分析仪、差示扫描量热仪、红外热成像仪和热重分析仪对所制备复合材料的微观结构、导热性能与相变过程进行了研究。结果表明:相比于PEG材料,片层三维网络结构的碳气凝胶可有效提高PEG的导热性能;碳气凝胶对PEG具有更加优良的定型效果,在相变过程中,能有效束缚PEG的流动,保持复合材料的形状稳定性。     

膨胀石墨相变储热复合材料的制备及性能研究

利用石墨高温膨胀得到多孔高吸附性膨胀石墨,吸附石蜡相变材料,制备了膨胀石墨石蜡相变储热复合材料。采用扫描电镜、差示扫描量热分析对复合材料的结构和性能进行了表征,研究了其储热释热行为。结果表明,在900℃时保持32 s膨胀后可得到适宜的膨胀石墨,吸附适量石蜡时仍保持定型特性,石墨的添加改善了复合材料的导热性能,提高了相变...     

脱硫石膏基相变砂浆的制备研究

以硬脂酸丁酯为相变材料、膨胀珍珠岩为载体,采用减压吸附法制备了定型相变材料,然后加入脱硫石膏和外加剂配制成相变砂浆。当定型相变材料添加的质量分数为15%(硬脂酸丁酯吸附的质量分数为45%)时制备的砂浆性能最好。对比相变砂浆和普通砂浆的降温曲线,相变砂浆具有温度调节功能,能够实现能源的合理利用。     

RT28/气相二氧化硅复合相变材料的制备及对锂离子电池的保温性能研究

利用气相二氧化硅吸附液态RT28,制备了RT28质量分数分别为60%、70%、80%的复合相变材料。液漏测试发现60%(wt)和70%(wt)含量的复合相变材料具有定型特性;采用扫描电镜(SEM)和傅立叶变换红外光谱仪(FT-IR)表征复合相变材料的微观结构和组份,利用Hot Disk热常数分析仪、差示扫描量热仪(DSC)测量其热物性。结果显示,复合相变材料为50~100 nm的团聚颗粒,气相二氧化硅与RT28复合仅为物理吸附;复合相变材料的热导率、相变焓和比热容均随着RT28含量的减少而降低。选用70%(wt)RT28的复合相变材料作为实验对象,其相变焓为155.4J×g~(-1),比热容为1.62 J×g~(-1)×℃~(-1),热导率为0.17 W×(m×K)~(-1),采用低温自然冷却的方法对锂离子电池的保温性能进行了测试,结果表明,包裹复合相变材料的锂离子电池的保温时间比没有相变材料的锂离子电池提高了160%,且其温度较稳定,受环境温度影响较少。     

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.