BTCA改性PEG/PVA相变储能纤维的结构与性能

将聚乙二醇(PEG)与聚乙烯醇(PVA)溶液混合,加入丁烷四羧酸(BTCA)作为交联剂配制纺丝原液,采用干法纺丝制得BTCA改性PEG/PVA相变储能纤维;研究了BTCA含量、热处理条件对交联程度的影响,并对纤维的结构、形态、储能性能及力学性能进行了分析。结果表明:在热处理温度为180℃,热处理时间为12 min时,纤维可达到良好的交联效果,纤维的交联程度随BTCA含量的增加呈上升趋势,BTCA质量分数为3%时达到平衡;改性纤维中PEG以独立微相区形式存在,而经热处理后可保留在交联网络中;热处理后的改性纤维力学性能随BTCA含量增加而提高,储能性能也增加且稳定;当BTCA质量分数为6%时,热处理后的纤维断裂强度达3.49 cN/dtex,再经沸水处理后纤维相变焓值可达23.01 J/g,PEG保留率达80%。     

聚乙二醇-聚乙烯醇相变储能纤维的制备及其性能

以聚乙二醇(PEG)为相变物质,聚乙烯醇(PVA)为纤维基体,加入少量丁烷四羧酸(BTCA)作为交联剂,采用干法纺丝制备相变储能纤维,利用原位交联法在纤维拉伸热定形过程中使BTCA与PVA、PEG发生交联,将PEG接枝在PVA上。研究了BTCA、PEG合适的添加量以及最佳热定形温度对PEG保留率的影响,并通过差示扫描量热法、扫描电镜对纤维的热性能和形貌进行了分析。结果表明:当PEG添加量为30%(占PVA质量的百分数)、BTCA添加量为5%(占PVA质量的百分数)时,纤维充分交联,200℃下热处理10 min所得纤维PEG的保留率98%;制得的纤维的相变热焓可达34 J/g,拉伸强度可达3.26 cN/dtex;在升降温循环400次后仍具有良好的储能性。     

角蛋白/聚乙烯醇复合纤维的制备及性能研究

以聚乙烯醇(PVA)和自制的羊毛角蛋白(WK)为原料,硼酸为交联剂,将WK与质量分数为15%的PVA溶液按质量比为2：10混合,制得含固体质量分数约为15%的WK/PVA共混纺丝原液,采用湿法纺丝的方法制备WK/PVA复合纤维,研究了复合纤维的结构与性能。结果表明:WK/PVA复合纤维的表面均出现皱纹,其横截面呈椭圆形;硼酸交联对WK/PVA复合纤维的形貌无明显影响,但使复合纤维的耐水性能得到提升;傅里叶变换红外光谱、X射线衍射光谱和热重分析结果证明了交联的发生,硼酸与WK和PVA大分子的交联改变了复合纤维的结晶结构,增强了大分子间的作用力,却使WK/PVA复合纤维的热稳定性降低。     

BTCA/Coll/PVA复合体系的交联动力学研究

以丁烷四羧酸(BTCA)为交联剂对胶原蛋白(Coll)/聚乙烯醇(PVA)复合体系进行化学交联处理;利用红外光谱分析了交联前后体系的化学变化;根据常见动力学机理函数,结合凝胶含量(α)研究复合体系的交联动力学。结果表明:BTCA对Coll/PVA体系有明显的交联作用,交联反应主要以酯化反应和酰胺化反应为主;BTCA/PVA和BTCA/Coll的表观凝胶反应活化能(E)分别为100.29,77.42 kJ/mol,表明BTCA较易与Coll反应;BTCA/Coll/PVA复合体系的最佳动力学函数G(α)为[-ln(1-α)]2/5,E为40.88 kJ/mol,比Coll/PVA复合体系的E(86.99 kJ/mol)明显减小,说明BTCA的加入降低了体系的E,有利于促进交联反应,可提高蛋白存留率。     

高含量胶原蛋白/PVA复合纤维的结构与性能

在胶原蛋白与聚乙烯醇(PVA)共混溶液中,加入连接剂三氯化铝和戊二醛,经湿法纺丝、热拉伸定型和后交联处理制得胶原蛋白质量分数为45.17%的胶原蛋白/PVA复合纤维,研究了复合纤维的结构与性能。结果表明:胶原蛋白/PVA复合纤维横截面呈圆形,具有皮芯结构,断裂强度和断裂伸长率分别为2.14cN/dtex和46.32%,结晶度为41.1%,水中软化点和回潮率分别为101℃和11.50%。     

聚乙烯醇/壳聚糖复合电纺纤维膜的制备及表征

利用静电纺丝法制备了聚乙烯醇PVA/壳聚糖CS纳米纤维复合膜,并采用戊二醛蒸气对其交联处理。通过扫描电子显微镜(SEM)观察探讨了不同质量配比、助纺剂的添加以及电纺环境条件对复合纤维膜纤维直径及表面形貌的影响。通过傅里叶变换红外光谱(FTIR)对PVA/CS复合纳米纤维膜做了特征官能团分析,并对其热力学性能及其耐水性进行了表征。结果表明滴加7%(V/V)二甲基亚砜、0.5%(V/V)丙三醇、0.5%(V/V)吐温80的3%(V/V)的乙酸为溶剂,PVA和CS质量配比为90/10,环境湿度0±15%电纺条件下制备的复合纤维形态均一,无珠串无液滴;FTIR研究显示,复合纤维的两种组分发生一定的相互作用,成功制备了戊二醛交联PVA/CS纳米纤维膜;热重(TG)、差热(DSC)结果都进一步说明CS和PVA之间形成氢键,戊二醛交联后复合纤维的热稳定性进一步增强。交联前后纤维膜的耐水性结果表明交联后的共混纤维膜有良好的抗溶解性,在水中可以很好的保持纤维的结构。     

PVA/SA/MF阻燃复合纤维的制备和性能研究

以聚乙烯醇(PVA)、海藻酸钠(SA)和三聚氰胺-甲醛树脂(MF)混合液为纺丝原液,采用湿法纺丝工艺制备PVA/SA/MF复合纤维。研究了PVA与SA及MF的共混比例对复合纤维阻燃性能和力学性能的影响。结果表明:PVA/SA/MF复合纤维的表面均匀光滑,其内部为网状结构;随着MF含量的增加,复合纤维阻燃性能增强,但其断裂强度呈现先增加后降低的趋势;当PVA∶SA∶MF质量比为10∶1∶4时,复合纤维的阻燃性能和力学性能均较好,其极限氧指数(LOI)为29. 8%,断裂强度为3. 19 c N/dtex;当PVA∶SA∶MF质量比为10∶1∶6时,复合纤维的阻燃性能、热性能及耐阻燃耐久性最好,其LOI为32. 0%,600℃时的质量保持率为24%左右,水洗50次后的LOI为25. 9%。     

静电纺淀粉/PVA纳米纤维的制备及其交联改性研究

为了提高淀粉纤维的力学性能和水稳定性,使淀粉纤维可以更好地应用于纺织、医药和生物工程等领域,采用静电纺丝法制备淀粉/聚乙烯醇(PVA)纳米纤维,并选择淀粉/PVA质量比为40/60的纳米纤维与戊二醛进行交联。通过扫描电镜、红外光谱(FTIR)仪、差示扫描量热(DSC)分析仪以及万能材料试验机等对纳米纤维的形貌、结构、热性能、力学性能和耐水性等进行了研究。结果表明:随着PVA含量的逐渐升高,淀粉/PVA纳米纤维的直径逐渐变小;FTIR和DSC测试显示淀粉和PVA仅仅是简单的物理共混;两种材料的共混可有效提高纳米纤维的力学性能,当淀粉/PVA质量比为40/60时,淀粉/PVA纳米纤维的力学性能最好;当淀粉/PVA纳米纤维与戊二醛进行交联3~24 h时,淀粉/PVA纳米纤维的接触角由28.31°提高到62.94°,其中交联时间9 h时,接触角为60.18°。     

利用静电纺丝制备CdTe量子点/聚乙烯醇复合纳米纤维及其荧光性能研究

将CdTe量子点(QDs)与聚乙烯醇(PVA)通过溶液共混,利用静电纺丝技术制备出CdTe QDs/PVA复合纳米纤维,通过扫描电子显微镜(SEM)、能量色散X-射线光谱(EDX)、分子荧光分光光度计和倒置荧光显微镜对复合纳米纤维进行微观形貌和荧光性能的研究。结果表明:当PVA含量为10%、CdTe QDs浓度为1.5mmol·L-1时,所制备的CdTe QDs/PVA复合纳米纤维的荧光性能最佳,且纳米纤维表面光滑、尺寸均匀,直径为200nm左右。与溶液浇铸法制得的CdTe QDs/PVA复合薄膜相比,该复合纳米纤维膜的荧光性能有所提高,说明CdTe QDs在复合纳米纤维中具有更好的稳定性和分散性。     

复合纺丝法制备PEG/PVA相变储能初生纤维

采用不同相对分子质量的聚乙二醇(PEG)与聚乙烯醇(PVA)进行湿法复合纺丝制备PEG/PVA相变储能初生纤维,对PEG与PVA溶液的相容性、PEG的凝固性能、PEG/PVA纤维的相变潜热及纤维形貌进行了研究。结果表明:PEG 2000与PVA复合纺丝得到的相变储能初生纤维具有较高的相变潜热,PEG 2000与PVA的质量比小于3:10时,PEG 2000在纺丝过程中流失量较小,纤维截面随着PEG 2000含量的增加而由肾形向圆形变化。     

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.