长玻纤增强聚丙烯复合材料的研究

研究了长玻璃纤维/PP复合材料的力学性能和纤维在基体中的分布状况。结果表明：长玻纤在基体中呈现三维空间交叉分布,这种结构大幅度提高了复合材料的拉伸强度、冲击强度、硬度及软化点温度；玻纤的长度和用量对三维交叉结构的形成有很大影响；偶联剂KH-550处理玻纤表面后,材料的力学性能提高不大。     

改性椰壳粉／PVC复合材料结构和性能的研究

研究了偶联剂改性椰壳粉的种类及用量、椰壳粉的质量分数对椰壳粉／PVC复合材料性能的影响,并用扫描电镜（SEM）观察了拉伸断面。结果表明：硅烷偶联剂KH-550质量分数为2％时效果较好,拉伸强度提高了12．6％,冲击强度提高了30．6％;经过硅烷偶联剂KH-550改性,能增大椰壳粉填充质量分数,提高复合材料的维卡软化点温度,改善了椰壳粉纤维在PVC基体中分散性和相容性。     

SA型透明尼龙/纳米SiO2复合材料力学性能及热性能研究

以SA型透明尼龙(PA)为基体,以KH-550处理的纳米S iO2为填料,采用熔融共混法制备了SA型透明PA/纳米S iO2复合材料。用微机控制电子万能试验机及简支梁冲击试验机测试了其力学性能;用维卡软化温度测定仪及差示扫描量热仪测试了其热性能。结果表明,SA型透明PA/纳米S iO2复合材料的弯曲弹性模量、弯曲强度和拉伸弹性模量均有较大提高,而拉伸强度、缺口冲击强度稍有降低;SA型透明PA/纳米S iO2复合材料的耐热性有明显提高。     

剑麻纤维/长玻纤混杂增强PP复合材料的力学性能研究

采用剑麻纤维(SF)和长玻璃纤维(LGF)混杂增强聚丙烯(PP)复合材料,考察了SF/LGF的比例和含量对PP复合材料力学性能的影响。结果表明:SF/LGF在聚丙烯树脂基体中呈交叉网状分布,这有利于提高复合材料的冲击强度、弯曲模量、拉伸强度和软化点。在SF/LGF质量比为2 2∶,二者总质量分数为30%时,SF/LGF混杂增强PP复合材料的综合力学性能较好。     

PA6/长玻纤/氯化钙复合材料结构与性能研究

采用熔融挤出工艺制备了尼龙(PA)6/长玻璃纤维(LGF)/氯化钙复合材料;研究了LGF含量对复合材料力学性能、维卡软化点、结晶性能的影响.结果表明,LGF的加入可以提高PA6的结晶速率和结晶度;当LGF质量分数为30％时结晶度最大,达到33.1％.随着LGF含量的增加,复合材料的力学性能及维卡软化点温度均大幅提高,当...     

聚乳酸/聚乙烯复合材料的制备与性能

通过熔融共混的方法制备了不同PE含量的PLA/PE复合材料，研究了PE含量对复合材料的力学性能、熔融与结晶行为、耐热性能、动态流变性能与微观结构的影响。结果表明，随着PE含量的增加，复合材料的拉伸强度、拉伸模量降低，复合材料的断裂伸长率、冲击强度得到提升，当PE含量为90%时，复合材料的断裂伸长率达到614.9%,与PLA相比，提高了92倍，试样无法冲断，材料的抗冲击韧性得到显著提高，PE使PLA结晶性能和结晶度提高，维卡软化点温度提升，当PE含量为90%时，复合材料的维卡软化点温度为85.3℃,与PLA相比，提高了44.3%,复合材料的耐热性和热稳定性显著提升，复合材料的复数黏度明显增大，PE的加入影响了PLA大分子链的松弛过程。     

PLA/Lyocell纤维复合材料结构与性能研究

以聚乳酸(PLA)为基体,新型纤维素纤维Lyocell纤维为增强材料,通过熔融共混及注塑成型制备了PLA/Lyocell纤维可生物降解复合材料,并采用扫描电镜(SEM)、力学性能测试、差示扫描量热法(DSC)和维卡软化温度测试等手段,探讨了Lyocell纤维含量对复合材料结构和性能的影响。结果表明:随着Lyocell纤维含量的增加,PLA/Lyocell纤维复合材料的结晶度、弯曲模量和维卡软化温度均随之提高,而拉伸强度和冲击强度则呈现先上升后下降的趋势。其中当Lyocell纤维含量达到6%时,其在复合材料中的分布较为均匀,所对应复合材料的力学性能相对较好,其拉伸强度、缺口冲击强度和弯曲模量比纯PLA分别提高了15.3%、12.3%和13.0%。     

玉米秸秆纤维素增强聚乳酸复合材料的制备及其界面改性?

采用注塑法制备了玉米秸秆纤维素/聚乳酸复合材料,并以三种不同偶联剂(硅烷偶联剂KH-550、钛酸酯偶联剂CS-201、六亚甲基二异氰酸酯HMDI)分别对复合材料进行界面改性,探讨了玉米秸秆纤维素的添加及偶联剂改性对复合材料力学性能、结晶性能、热性能、界面形貌和亲水性能等影响。结果表明:玉米秸秆纤维素的加入可有效提高复合材料的拉伸强度和结晶度,提升了复合材料的耐热性和亲水性;与未处理的复合材料相比较,偶联剂改性处理明显改善了纤维素与聚乳酸基体间的界面结合,进一步提高了复合材料的拉伸强度、冲击强度和维卡软化温度,但复合材料的亲水性和结晶度有所降低。综合来看,在三种偶联剂用量均为纤维素含量1%的条件下,HMDI的偶联改性效果最佳,KH550次之,钛酸酯CS-201的偶联改性效果则较为一般。     

LDPE/剑麻纤维素微晶复合材料性能研究

采用熔融共混法制备低密度聚乙烯(LDPE)/剑麻纤维素微晶(SFCM)复合材料,研究了SFCM的用量对LDPE/SFCM复合材料的力学性能、维卡软化点、熔体流动速率及熔融结晶行为的影响。力学性能测试表明:SFCM的加入可明显提高基体LDPE的拉伸弹性模量、弯曲强度及模量,但降低了体系的拉伸强度。当加入3份的SFCM时,LDPE/SFCM复合材料的缺口冲击强度最大,为46.9 k J/m~2,比纯LDPE提高了33.2%。热性能、流动性能及DSC研究表明:SFCM的加入对LDPE/SFCM复合材料的维卡软化点、熔融温度及结晶温度影响不明显,但降低了复合材料的熔体流动速率,同时LDPE的结晶度明显提高。     

不同硅烷偶联剂对聚丙烯/凹凸棒土复合材料性能的影响

分别以硅烷偶联剂Si69、Si75、KH550和NXT对凹凸棒土(ATT)进行表面处理,再采用熔融共混的方法制备了聚丙烯(PP)/ATT复合材料。通过力学性能测试、差热分析(DSC)、扫描电镜(SEM)观察研究了硅烷偶联剂种类和ATT用量对复合材料拉伸强度、简支梁缺口冲击强度、熔体质量流动速率(MFR)、维卡软化温度、微观形态和结晶性能的影响。结果表明:随着ATT用量的增加,PP/ATT复合材料的拉伸强度、简支梁缺口冲击强度和MFR呈现先升后降的趋势,维卡软化温度则随之升高;ATT经偶联剂表面处理后,其在PP基体中的分散效果有较大改善,同时有效促进了复合材料中PP的结晶;另外,4种硅烷偶联剂中,NXT的改性效果最佳。     

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.     

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.