溴代三嗪阻燃剂对LGF/PA6复合材料阻燃机理及降解行为的影响

利用溴代三嗪(BrN)协同三氧化二锑(Sb2O3)制备N-Br-Sb阻燃长玻纤增强尼龙6复合材料(BrN/LGF/PA6),通过极限氧指数(LOI)、垂直燃烧(UL94)、热重分析法(TGA)、锥形量热分析(CONE)、红外光谱分析(FTIR)、扫描电镜(SEM)等方法研究了BrN协同Sb2O3对长玻纤增强尼龙6复合材料阻燃性能影响.结果表明,在BrN与Sb2O3的协效阻燃体系添加量为16％时,可使BrN/LGF/PA6复合材料的阻燃等级达到FV-0级,LOI为26.9％.锥形量热与热失重分析均表明,BrN协同Sb2O3能提高BrN/LGF/PA6复合材料的高温下热稳定性,促进PA6分解成炭,从而起到良好的阻燃作用.红外光谱、扫描电镜和锥形量热分析表明,LGF/PA6与BrN/LGF/PA6复合材料热处理后的炭层结构不完全相同,说明了BrN协同Sb2O3不仅在气相发挥阻燃作用,在固相也同样发挥阻燃作用.     

溴化聚苯乙烯阻燃长玻璃纤维/PA6复合材料性能的研究

利用溴化聚苯乙烯(BPS)协同三氧化二锑(Sb2O3)制备新型卤素阻燃长玻璃纤维(LGF)增强尼龙6复合材料(BPS/LGF/PA6),通过极限氧指数(LOI)、垂直燃烧(UL94)、热重分析法(TGA)、锥形量热(cone)等方法研究了BPS协同Sb2O3对LGF/PA6复合材料阻燃性能影响。结果表明,在BPS与Sb2O3的协效阻燃体系的质量分数为16%时,可使BPS/LGF/PA6复合材料的阻燃等级达到FV-0级,LOI为25.2%。而且,BPS协同Sb2O3能提高BPS/LGF/PA6复合材料的热稳定性,缓解PA6分解速率,从而起到良好的阻燃作用,成功地解决了玻纤增强材料燃烧时的"烛芯效应"问题。     

OMMT -卤-锑阻燃体系对 PA6／LGF 复合材料的影响

利用有机蒙脱土（ OMMT）协同溴代环氧树脂（ BER）、三氧化二锑（ Sb2 O3）通过熔融插层法制备OMMT-卤-锑阻燃长玻纤增强尼龙6复合材料（OMMT/FR/PA6/LGF）,通过极限氧指数（LOI）、垂直燃烧（UL-94）、锥形量热分析（CONE）、热失重分析（ TGA）、扫描电镜（ SEM）等方法研究了不同质量比的OMMT-卤-锑阻燃体系对OMMT/FR/PA6/LGF复合材料成炭、阻燃、燃烧、力学性能以及热稳定性的影响。结果表明,当OMMT添加量为2％, BER/Sb2 O3添加量为10％时,二者表现出优异的协同阻燃效应,不仅能促使OMMT/FR/PA6/LGF复合材料生成的炭层结构最为致密、均匀、连续,氧指数值最高且能保持FV-0级,还对复合材料的力学性能影响相对最小。     

热氧老化时间对PA6/LGF/BEP复合材料性能的影响

探究了160℃温度下不同热氧老化时间对溴化环氧树脂(BEP)阻燃长玻纤增强尼龙6(PA6/LGF/BEP)复合材料性能的影响。通过热重分析(TGA)、氧指数(LOI)及锥形量热仪测试,分析了不同热氧老化时间下PA6/LGF/BEP复合材料的热稳定性、阻燃性能、燃烧性能。结果表明:热氧老化时间的延长对PA6/LGF/BEP复合材料的热稳定性影响不大,但热氧老化时间的延长使复合材料的氧指数由25%降低到23.2%,最大热释放速率由138 kW/m~2增加到316 kW/m~2,火势增长指数由1.31 kW/(m~2·s)增加到3.01 kW/(m~2·s),这表明随着热氧老化时间的延长,该复合材料的阻燃性能下降,火灾安全性逐渐降低。     

热氧老化对溴化聚苯乙烯阻燃LGF/PA6复合材料表层结构性能的影响

研究了160℃条件下,不同热氧老化时间对溴化聚苯乙烯与三氧化二锑复配阻燃长玻纤增强尼龙6复合材料(FR/LGF/PA6)表面热稳定性、结晶度及表面形貌、结构变化的影响,并采用热重分析、差示扫描量热法分析、傅里叶红外光谱技术和扫描电子显微镜在热与氧共同作用下对FR/LGF/PA6复合材料表层结构与性能的影响进行了表征。结果表明:热氧老化导致的FR/LGF/PA6复合材料表层基体分子链的断裂、降解以及形成的微裂纹、凹坑是导致表层复合材料熔融温度、结晶度、热稳定性降低以及表面结构变化的主因。热氧老化处理50 d后,FR/LGF/PA6复合材料表层结构的结晶度减小25.4%,且易形成生色基团使材料发生黄化。     

无卤阻燃长玻纤增强尼龙66的制备及性能表征

以二乙基次膦酸铝(ADP)为阻燃剂,三聚氰胺聚磷酸盐(MPP)和氧化铈(CeO_2)为阻燃协效剂制备了无卤阻燃长玻纤增强尼龙66(LGF/PA66)复合材料。当LGF/PA66/ADP/MPP/CeO_2质量比为30/55/10/3/2时,制备的复合材料垂直燃烧可以达到UL-94 V-0等级。扫描电镜和锥形量热仪分析测试表明:MPP通过气相阻燃可以有效地抑制玻纤的灯芯作用,CeO_2可以催化PA66成炭,使炭层更致密,同时降低了最大热释放速率,具有良好的阻燃协效作用。     

溴化环氧树脂协同三氧化二锑阻燃PET的燃烧性能及阻燃机理研究

研究了溴化环氧树脂(BER)协同不同粒径的三氧化二锑（Sb2O3）阻燃PET的燃烧性能、垂直燃烧性能（UL94）、烟气释放、物理性能高和力学性能,研究了炭层的红外光谱和阻燃PET的裂解特性,分析了阻燃PET的阻燃机理。锥形量热分析表明,BER协同Sb2O3阻燃PET的燃烧性能显著减低,均可以达到UL94 V-0级,且Sb2O3粒径越小,阻燃效果越好,但溴-锑协同不能抑制烟毒的产生,平均CO生成量和材料释烟量显著上升。BER协同Sb2O3阻燃PET的熔体流动速率、维卡软化点、邵氏硬度、弯曲强度和弯曲模量提高,缺口冲击强度和断裂伸长率下降。红外和裂解色谱分析表明,阻燃PET与纯PET的燃烧残炭结构不完全相同,裂解产物的主要出峰保留时间也不相同,说明了BER协同Sb2O3不仅在气相发挥阻燃作用,在固相也同样发挥阻燃作用。     

水滑石对PBS/Sb2O3阻燃PA6/GF性能的影响

研究了聚溴化苯乙烯(PBS)对玻纤增强尼龙6(PA6/GF)阻燃和力学性能的影响,并采用锥形量热仪研究了改性水滑石(HT)对PBS/Sb2O3阻燃PA6/GF抑烟作用和燃烧时热释放速率的影响。结果表明,随PBS用量增加,PA6/GF的氧指数增加,阻燃性提高,当PBS质量分数为20%时,PA6/GF的垂直燃烧达到FV-0级;HT燃烧后形成多孔、大比表面积的镁铝复合氧化物,能够有效吸附材料燃烧过程中产生的炭微粒,对PBS/Sb2O3阻燃PA6/GF具有显著的抑烟作用。当HT质量分数为5%时,烟释放速率降低27.6%,且对阻燃PA6/GF的力学性能影响不大。另外,HT使PA6/GF的氧指数和相比漏电起痕指数(CTI)提高。     

PP/LGF复合材料的膨胀性阻燃与协效阻燃性能

采用膨胀型阻燃剂(IFR)及协效剂海泡石(SP)对长玻璃纤维增强聚丙烯(PP/LGF)复合材料进行阻燃,通过双螺杆挤出机制备了PP/LGF母粒,IFR母粒和SP母粒,然后将这3种母粒通过注塑机制备了PP/LGF/IFR/SP复合材料,通过极限氧指数(LOI)、垂直燃烧测试、锥形量热仪、热重分析、扫描电子显微镜、力学性能测试等表征PP/LGF各阻燃复合体系的性能。结果表明,当IFR质量分数为22%时,PP/LGF/IFR阻燃复合材料的LOI为28.8%,且垂直燃烧等级达到V–0级;锥形量热仪测试结果表明加入IFR及SP后阻燃复合体系的第一热释放速率峰值降低,而第二热释放速率峰消失;SP质量分数为1%,IFR质量分数为21%的PP/LGF/IFR/SP阻燃复合材料LOI为29.6%,垂直燃烧等级达到V–0级,热释放速率峰值和总热释放量得到有效降低,热稳定性最好,且燃烧时产生致密的炭层覆盖于玻璃纤维表面,同时加入1%SP后复合材料的力学性能下降幅度相对较小。     

硅胶与膨胀型阻燃剂复配阻燃LGF/PP复合材料的性能研究

研究硅胶(SG)作为协效剂与IFR协同阻燃LGF/PP复合材料的性能。通过极限氧指数(LOI)、垂直燃烧(UL-94)、锥形量热仪(CONE)、热重分析法(TG)、扫描电子显微镜(SEM)、力学性能等测试表征LGF/PP/IFR/SG阻燃复合体系的性能。结果表明:当硅胶用量为2%时,阻燃复合材料的LOI为29.4%,且燃烧等级达到V-0级;CONE测试结果表明LGF/PP/IFR/SG阻燃复合材料的第一热释放速率峰值降低,而第二热释放速率峰消失;LGF/PP/IFR/SG阻燃复合材料具有较好的热稳定性,且产生致密均匀的炭层;并研究硅胶用量对复合材料力学性能的影响。     

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。