氨气等离子体改性处理芳纶Ⅲ表面的研究

以氨气为反应气体,对芳纶Ⅲ进行等离子体表面改性处理,研究了等离子体处理时间和处理功率对纤维表面性能的影响;采用X射线光电子能谱、场发射扫描电镜、接触角和微脱粘实验等测试方法对改性前后纤维表面元素组成、形貌、润湿能力以及界面粘结强度进行表征。结果表明:芳纶Ⅲ经过氨气等离子体改性后,表面含氮极性基团的含量增加,粗糙程度增大,润湿能力得到明显的改善;当氨气等离子体处理时间为15 min,功率为100 W时,芳纶Ⅲ与环氧树脂的界面粘结强度从处理前的12.9 MPa提高到18.2 MPa,与水的接触角由处理前的71.4°下降到46.8°。     

羟基硅油改性磺酸型水性聚氨酯的合成及性能

以磺酸型聚酯二元醇(BY3301)、甲苯二异氰酸酯(TDI)为主要原料,羟基硅油为改性剂,三羟甲基丙烷(TMP)为交联剂,合成了羟基硅油改性磺酸型水性聚氨酯。采用FTIR、TG、数显黏度计、纳米粒度仪表征了聚合物的结构与性能,探讨了羟基硅油含量对乳液及胶膜性能的影响。结果表明:随着羟基硅油含量增加,乳液粒径增大,黏度降低;胶膜表面水接触角增大,吸水率先减小后增大;胶膜拉伸强度增强,断裂伸长率先增大后减小。当羟基硅油占预聚体质量的3%时,聚合物性能最佳,其乳液粒径为85.1 nm,黏度为114.5 mPa·s,胶膜水接触角为91.7?,拉伸强度为14.78 MPa,断裂伸长率为427%,24 h吸水率仅为5.61%,由TG曲线可知,胶膜质量损失5%时,对应温度为269.9℃,较之改性前提高17.3℃。     

氟硅改性聚氨酯-羟基丙烯酸酯复合乳液的制备与性能研究

利用无皂乳液聚合法制备了含端羟基聚醚改性硅油(THPDMS)的氟硅双改性聚氨酯-丙烯酸酯复合乳液(WPUA),系统研究了甲基丙烯酸十二氟庚酯(DFHMA)、甲基丙烯酸羟乙酯(HEMA)含量对乳液及胶膜性能的影响。结果表明,随着DFHMA和HEMA含量的增加,复合乳液的粒径及分散系数增大;WPUA中引入氟单体DFHMA能明显地降低涂层的表面能,降低幅度达40%左右;当F含量增至5.08%时,表面能降低趋势渐缓,水、油的接触角最高达118.0°和78.2°,涂层表现出明显的双疏性;随着HEMA和交联剂N3300含量增加,胶膜交联密度增大,吸水率逐渐降低,最低可达5.54%,同时胶膜的拉伸强度明显增强,当w(HEMA)由0增加至4.66%时,拉伸强度由15.7 MPa提升至36.0 MPa,获得高强度的WPUA胶膜;此外,HEMA和DFHMA引入WPUA中,增加了涂层的热稳定性,其初始分解温度提高10℃左右。     

UP/PU嵌段共聚树脂/玻璃纤维界面粘结性的研究

合成了一种异氰酸酯嵌段共聚改性不饱和聚酯树脂(UP/PU),并以玻纤增强制备了复合材料(GFRP)。通过接触角、拉伸性能、弯曲性能测定和扫描电镜观察研究了UP/PU GFRP界面的粘结性能。结果表明:UP/PU树脂与玻璃表面的接触角为20°,对玻璃表面的润湿性较通用邻苯型UP好;GFRP拉伸强度1 050 MPa,弯曲强度1 220 MPa,较通用邻苯型UP的GFRP分别提高了145%和78%,说明UP/PU与玻纤的界面粘结性能较好。     

介质阻挡放电等离子体处理芳纶的表面性能研究

采用介质阻挡放电(DBD)装置对芳纶1414表面进行改性处理,探讨低温等离子体处理对纤维表面性能的影响。结果表明:经过DBD等离子体处理后,芳纶1414纤维表面粗糙程度加剧,粘结性能和浸润性能有了明显的改善;当DBD等离子体处理功率为200～300 W,时间为60 s,氩气流量为2～3 L/min时,芳纶1414的界面剪切强度从处理前的11.9 MPa上升到14.2 MPa,接触角由处理前的85.0°下降到了60.6°。     

芳纶纤维/AFR树脂复合材料界面粘结性能的研究

为了改善芳纶纤维复合材料的界面粘结性能,合成了一种新型树脂(AFR)作为基体,以未经任何表面处理的芳纶纤维作增强材料,制备了芳纶纤维/AFR复合材料。采用测定表面能、接触角、层间剪切强度、横向拉伸性能和扫描电镜观察形貌等方法,从宏观和微观等方面研究了芳纶纤维/AFR复合材料的界面粘结性能。结果表明,AFR树脂与芳纶纤维有相近的表面能,AFR树脂溶液与芳纶纤维的接触角为42.8°,而环氧树脂(EP)与芳纶纤维的接触角为68°,说明AFR树脂对芳纶纤维的润湿性优于EP树脂;芳纶/AFR复合材料的层间剪切强度、横向拉伸强度和纵向拉伸强度分别为74.64MPa、25.34MPa和2256MPa,比芳纶/EP复合材料的相应强度分别提高了28.7%、32.5%和13.4%,其复合材料破坏面的形貌也说明芳纶纤维与AFR树脂之间的界面粘结性能较好。     

蓖麻油改性磺酸型水性聚氨酯性能研究

采用蓖麻油、异佛尔酮二异氰酸酯(IPDI)、聚己内酯二元醇(PCL)和1,4-丁二醇(BDO)为主要原料,以乙二胺基乙磺酸钠(AAS)为亲水基,合成了一系列由蓖麻油改性的磺酸型水性聚氨酯乳液,并固化成膜。通过FT-IR、粒径测试、吸水率与接触角测定、力学性能测定、TG等手段研究了蓖麻油含量对水性聚氨酯乳液与胶膜的影响。结果表明:蓖麻油成功接入聚氨酯分子主链中;随着蓖麻油含量的增加,乳液粒径逐渐增大;胶膜的吸水率先减小后增大,接触角先增大后减小,拉伸强度先增大后减小,断裂伸长率逐渐减小。当蓖麻油与PCL质量比为0.5时,胶膜吸水率最小,接触角最大,为95.18°,拉伸强度最大,为15.15 MPa,综合性能最好。通过TGA表明,蓖麻油的引入,胶膜的耐热性也有所提高。     

PBO纤维表面改性及其与树脂基体界面性能研究

分别采用化学处理、等离子体处理、偶联剂处理、γ射线辐照等单一改性方法和“辐照+等离子体”、“辐照+等离子体+偶联剂”等综合改性方法对PBO纤维进行表面处理,之后对各种不同方法改性后的纤维进行了单丝拉伸强度、与树脂的接触角和单丝拔出性能测试.结果表明,经综合改性方法处理后的PBO纤维综合性能最优,单丝拉伸强度保持率为85.1％,与水的接触角达到74.15°;与未经表面处理的纤维相比,其与树脂基体间的粘结强度提高了48.6％.     

芦苇/碳纤维增强PP/EVA复合材料的制备及性能研究

采用双辊开炼机将芦苇纤维(LF)、碳纤维(CF)与聚丙烯(PP)、聚醋酸乙烯酯(EVA)进行熔融共混,制备了PP/EVA/LF/CF复合材料,以及LF经碱处理、CF经硫酸/硅烷偶联剂处理后,制备了PP/EVA/改性芦苇纤维(ALF)/改性碳纤维(SSi CF)复合材料,研究了2种纤维复配质量比对复合材料力学性能的影响,探讨了复配改性纤维对复合材料接触角、热稳定性的影响。结果表明:当LF与CF复配质量比为1∶5时,PP/EVA/LF/CF复合材料的综合力学性能较好;与PP/EVA复合材料相比,ALF与SSi CF复配质量比为1∶5时,PP/EVA/ALF/SSi CF的拉伸强度提高了11.13 MPa,弯曲强度提高了16.31MPa,冲击强度降低;PP/EVA/ALF/SSi CF复合材料较PP/EVA复合材料的表面亲水接触角提高了7°,残炭率由0增加至23.1%,热稳定性明显提高。     

改性纳米贝壳粉对天然橡胶复合材料力学性能的影响

采用钛酸酯对纳米贝壳粉(SP)进行了表面改性,并制备了改性纳米贝壳粉;通过与天然胶乳共混,制备了天然橡胶/贝壳粉(NR/SP)纳米复合材料;使用傅里叶红外光谱仪、扫描电子显微镜、表面接触角测定仪、XRD衍射分析仪、激光粒度仪和电子拉力试验机等研究了改性纳米贝壳粉对天然橡胶纳米复合材料力学性能的影响。结果表明,改性剂钛酸酯成功地偶联到贝壳粉表面,经过表面化学改性后贝壳粉表面接触角由73.5°增大到110.8°;当纳米贝壳粉用量为10%时,NR/SP复合材料可获得最佳力学性能,拉伸强度可达到34.05MPa。     

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。