尼龙基MCA母粒的制备及其在阻燃尼龙的应用

针对三聚氰胺氰尿酸盐(MCA)粉体对尼龙(PA)进行阻燃改性时,MCA分散性差,材料阻燃性能不稳定的问题,运用特殊的包覆工艺成功制得了PA基MCA母粒。将制得的MCA母粒及MCA粉体分别与PA6或PA66共混挤出,制得阻燃PA材料。对比分析了MCA母粒及MCA粉体阻燃PA6或PA66的垂直燃烧性能和力学性能。结果表明,与MCA粉体相比,MCA母粒可在MCA含量较低的情况下使厚度为0.8 mm及1.6 mm的阻燃PA6或PA66试样的垂直燃烧等级达到V–0级。MCA母粒及粉体对阻燃PA6的弯曲强度和PA66的拉伸强度影响很小,MCA母粒阻燃PA6的拉伸强度较粉体阻燃的高,而阻燃PA66的弯曲强度低;MCA母粒使阻燃PA的缺口冲击强度降低,而MCA粉体对PA的缺口冲击强度影响较小,当MCA含量较低时,MCA母粒阻燃PA的缺口冲击强度明显高于MCA粉体阻燃的PA。制备的MCA阻燃母粒对PA的阻燃效果不受黑色母料的影响,且具有较好的阻燃稳定性。     

氮–磷协效阻燃聚酰胺66制备与性能

为改善聚酰胺66(PA66)的阻燃性能,以氮系阻燃剂三聚氰胺氰尿酸盐(MCA)和磷系阻燃剂9,10–二氢–9–氧杂–10–磷酰杂菲–丁二酸(DDP)协效,将原位聚合法与共聚法结合,经熔融缩聚制备氮-磷协效阻燃PA66树脂。利用傅立叶变换红外光谱仪、差示扫描量热仪、万能材料试验机、垂直燃烧仪和极限氧指数仪等研究阻燃PA66树脂的结构与性能。结果表明:随DDP含量的增加,阻燃PA66的相对黏度、熔点、结晶度和力学性能均呈下降趋势。当MCA含量为2%,DDP含量为4%时,阻燃PA66(FRPA66–4)的熔点、结晶温度和结晶度分别降至250.78℃,203.74℃,29.21%,FRPA66–4的拉伸强度和断裂伸长率分别下降为68.8 MPa和69.5%,比PA66降低了17.01%和17.46%。但PA66的阻燃性能得到改善,FRPA66–4的垂直燃烧测试达UL94 V–0级,极限氧指数为30.6%,阻燃效果良好。     

原位聚合法制备N-P复配型阻燃PA66树脂及性能

以4-(2-(((2-羧基乙烷基)(苯基)磷酰基)氧)乙氧基)-4-氧代己酸(CPPOA)和三聚氰胺氰尿酸盐(MCA)为阻燃单元,通过原位聚合法制备了N-P复配型阻燃尼龙66(PA66)树脂。相对黏度测试表明,阻燃单元的引入会造成PA66树脂分子量下降。力学性能测试结果显示,阻燃PA66的拉伸强度、冲击强度、弯曲强度以及弯曲模量均有所下降。极限氧指数及垂直燃烧测试结果显示,阻燃PA66具有良好的阻燃性能,当CPPOA和MCA的含量均为4%时,阻燃PA66树脂的极限氧指数及阻燃等级分别达到28.7%和UL-94 V-0级。XRD测试表明,阻燃改性未改变PA66的晶型结构。DSC测试表明,阻燃改性后,尼龙树脂的熔融温度、结晶温度和结晶度均呈下降趋势。TGA结果表明,阻燃PA66的初始分解温度较纯PA66下降,但成炭率提高。     

无机填料对PA6/MCA阻燃复合材料性能的影响

研究了不同种类的无机填料(硅灰石、碳酸钙)对尼龙6(PA6)/三聚氰胺氰尿酸盐(MCA)阻燃复合材料性能的影响。阻燃性能测试结果表明,PA6/MCA/硅灰石阻燃复合材料为UL94 V–0级,比PA6/MCA阻燃复合材料(V–2级)有显著提高;然而PA6/MCA/碳酸钙阻燃复合材料的极限氧指数却有所下降。扫描电子显微镜测试分析表明,PA6/MCA/硅灰石阻燃复合材料燃烧后的表面炭层呈连续、致密状;PA6/MCA/碳酸钙阻燃复合材料的表面炭层有很多孔洞,且孔洞直径大。傅立叶变换红外光谱测试结果表明,PA6/MCA/硅灰石阻燃复合材料的表面炭层与Si O2能很好地结合,形成致密的保护层,致使其阻燃性能显著提高。另外,力学性能测试结果表明,硅灰石能够提高PA6/MCA阻燃复合材料的拉伸强度,但降低了缺口冲击强度,而碳酸钙的加入却使得PA6/MCA阻燃复合材料的综合力学性能有所下降。     

滑石粉填充对PA66/MCA体系的性能影响

采用不同滑石粉对聚酰胺66/三聚氰胺氰尿酸盐(PA66/MCA)进行填充改性,探讨滑石粉对其体系的阻燃和力学性能的影响和机理。结果发现:随着滑石粉添加量的增加,PA66/MCA/Talc复合体系的熔融流动性变差,影响材料燃烧时的熔滴效果而引起样条自燃时间的增加,在滑石粉含量达20 phr后影响显著。MCA的最佳含量在10 phr左右,PA66/MCA/Talc材料可达到良好阻燃效果。在此最优MCA含量下,滑石粉能增加PA66/MCA的模量但会降低材料的冲击强度和延展性,在不高于5 phr能增加PA66/MCA拉伸强度但在10 phr以后会降低其拉伸性能。此外,滑石粉的比表面积越大,PA66/MCA/Talc材料的阻燃性能和综合力学性能越优越。     

不同原始颗粒尺寸的PHE对PA66/PHE共混物力学性能影响

使用不同原始颗粒尺寸的聚酚氧(PHE)通过双螺杆挤出机分别与尼龙(PA)66共混制备PA66/PHE共混物.测试其力学性能,并用扫描电子显微镜(SEM)表征.研究发现,小颗粒尺寸的PHE制备的PA66/PHE共混物的分散相尺寸小、分散均匀且冲击强度得到提高,呈现协同效应,而拉伸强度基本与纯PA66保持一致;大颗粒尺寸的PHE制备的PA66/PHE共混物的分散相尺寸较大且容易发生团聚,其冲击强度降低,而拉伸强度有所增加.     

高性能无卤阻燃PA66的制备和性能研究

将白色颜料钛白粉、硫化锌与复配无卤阻燃剂三聚氰胺异氰尿酸盐(MCA)/三氧化二锑(Sb_2O_3)、尼龙66(PA66)共混,经双螺杆挤出机挤出造粒,制备无卤阻燃PA66复合材料,研究了不同阻燃体系对材料阻燃性能的影响,并对比了钛白粉、硫化锌对材料力学性能的影响,研究发现采用MCA+30%Sb_2O_3复配在添加10份时即能达到V-0(1.6 mm)级别,无卤阻燃PA66的拉伸强度、弯曲模量随着白色颜料钛白粉、硫化锌含量的增加而增加,缺口冲击强度随之减小,其中硫化锌对材料的力学性能影响相对较小,具有更好的缺口冲击强度。     

阻燃热塑性聚酯弹性体复合材料制备及性能

以二乙基亚膦酸铝盐(AlPi)和三聚氰胺氰脲酸盐(MCA)为阻燃剂,添加到热塑性聚酯弹性体(TPEE)中,采用挤出造粒方法制备出高性价比的阻燃TPEE复合材料。首先采用热失重分析仪研究了两种阻燃剂的热稳定性,进一步采用热失重分析、极限氧指数测试、垂直燃烧测试、力学性能测试以及扫描电子显微镜等对阻燃TPEE材料的热稳定性、阻燃性能、燃烧性能、力学性能以及复合材料的微观形貌进行了研究。结果表明,在相同阻燃剂用量下,添加AlPi的阻燃复合材料的阻燃效果、力学性能均优于添加MCA的阻燃复合材料,采用AlPi与MCA复配使用制备的阻燃TPEE复合材料的阻燃效果、力学性能介于二者之间,当TPEE,AlPi和MCA用量分别为83%,10%和5%时,阻燃复合材料的拉伸强度为24.19 MPa,断裂伸长率为515%,极限氧指数为30%,垂直燃烧测试达到V–0级。AlPi与MCA复配使用可提升阻燃TPEE材料的成炭性能和高温热稳定性。     

MCA阻燃PA66的研究

通过扫描电子显微镜、热重分析–傅立叶变换红外光谱、差示扫描量热等研究了三聚氰胺氰尿酸盐(MCA)阻燃PA66体系的微观形貌与性能。结果表明,MCA在PA66体系中呈片状分布,但随用量的增加有一定的团聚现象;MCA与PA66存在一定的相互作用而使得MCA和PA66的热稳定性均下降,PA66/MCA体系中第二阶段的分解产物与未加MCA的PA66基本相同;MCA具有异相成核作用但会降低结晶速度。同时考察了不同含量MCA、不同加工助剂、着色剂对材料性能的影响。当MCA质量分数为5%~10%时,阻燃等级达到UL 94 V–0级,同时力学性能较好,加工助剂及着色剂中硬脂酸钙、EBS、络合红R297对阻燃性能没有负面影响,但蒙旦酯蜡、PE基黑种、铁红R206对阻燃性能有负面影响。     

环保型无卤阻燃剂在PA6材料中的应用

以聚酰胺(PA) 6为基体材料,添加二乙基次膦酸铝(ADP)、三聚氰胺氰尿酸盐(MCA)为阻燃剂,通过熔融共混制备无卤阻燃PA6复合材料。采用水平垂直燃烧仪、氧指数测定仪、万能材料试验机以及热重分析仪研究了ADP和MCA用量对无卤阻燃PA6阻燃性能、力学性能、热降解行为的影响,并采用扫描电子显微镜观察了燃烧后炭层的形貌,探讨了ADP与MCA间的协效阻燃作用。结果表明,制备的阻燃PA6复合材料均能达到UL94 V–0阻燃级别;当ADP添加量为18%时,极限氧指数(LOI)可达33.3%;当添加14% ADP时,ADP/MCA复配阻燃体系的LOI值保持在31%以上;MCA对ADP产生协效阻燃作用,MCA的加入使得热分解温度降低,加速了PA6在燃烧时的成炭,改善了炭层结构,并使PA6具有较好的力学性能。     

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。