改性纳米磷酸锆对膨胀阻燃聚丙烯性能的影响

以多聚磷酸铵(APP)和季戊四醇(PER)为阻燃体系模板,研究了改性纳米磷酸锆(n-ZrP)对膨胀阻燃聚丙烯复合材料(PP/IFR)阻燃性能的影响,并且采用热重分析(TGA)、红外光谱(FTIR)和扫描电镜(SEM)研究了n-ZrP的阻燃协同作用机理。阻燃性能的研究表明,n-ZrP能够明显改善复合材料的阻燃效果;当n-ZrP添加量为2%时,PP/IFR复合材料的氧指数值达到了31.6%,通过了UL 94 V-0级测试;当n-ZrP添加量为0.5%时,其催化效率达到最高。TGA分析结果表明,n-ZrP能够促使阻燃复合材料提前降解,并保留更多的残碳。FTIR和SEM结果表明,n-ZrP能够起到片层阻隔作用并催化IFR的酯化和交联反应,形成更多含磷的交联结构(P—O—C和P—O—P的),提高炭层的致密程度,从而改善复合材料的阻燃性能。     

一种超支化三嗪成炭剂对聚丙烯阻燃性能的影响

一种新型超支化三嗪成炭剂(HCT)与多聚磷酸铵(APP)复配成膨胀型阻燃剂(IFR),与聚丙烯(PP)熔融共混制备阻燃PP复合材料,采用垂直燃烧实验、红外光谱、扫描电镜对其阻燃性能和阻燃机理进行了研究。结果表明,当IFR加量为25%、APP∶HCT质量比为3∶1时,阻燃性能达到UL94 V-0级,并表现出较好的耐水性能。其阻燃机理是APP受热分解成HPO_3,HPO_3分子与三嗪环上的氨基发生脱水交联形成P—N、P—C交联的致密炭层。     

ABS新型无卤膨胀阻燃体系的研究

以聚磷酸铵(APP)为酸源,聚对苯二甲酰己二胺(PA6T)为炭源,探讨了不同比例的APP/PA6T复配对丙烯腈-苯乙烯-丁二烯共聚物(ABS)燃烧性能及其降解成炭行为的影响。结果表明,当APP含量为25%、PA6T含量为5%时,阻燃体系的极限氧指数达到29%,通过UL-94测试V-1级;再添加2%协效剂次磷酸铝,可通过V-0级。热失重分析表明,PA6T有较好的成炭作用,APP能极大改变PA6T的热分解行为,使ABS/APP/PA6T阻燃体系的高温残炭率大大提高。SEM形貌分析表明,阻燃体系燃烧表面形成了膨胀、均匀、致密的炭层结构。此外,通过对残炭进行红外分析,发现存在化学键P—O—C,进一步验证了该膨胀阻燃体系的协效成炭行为。     

硫酸锌对膨胀阻燃聚丙烯体系性能的影响

将硫酸锌添加到聚磷酸铵(APP)和双季戊四醇(DPER)膨胀阻燃聚丙烯(PP)体系中,采用氧指数(OI)、垂直燃烧(UL 94)、热分析(TGA)、红外光谱(FTIR)和扫描电镜(SEM)等分析方法,考察了硫酸锌对膨胀阻燃PP体系性能的影响,探讨其作用机理。结果表明:添加适量硫酸锌可以显著提高膨胀阻燃PP体系的氧指数和垂直燃烧性能,且少量添加不影响体系的力学性能和热老化性能;硫酸锌的作用对象主要是APP和DPER,它可以促进APP的交联,与DPER发生化学反应,从而改变DPER的失重过程;硫酸锌可以改善膨胀炭层的形貌,提高炭层的隔热隔质能力。     

锡酸锌协效阻燃聚丙烯

通过水热法合成锡酸锌(Zn2Sn O4),将所得Zn2Sn O4作为协效剂加入聚丙烯(PP)/聚磷酸铵(APP)/季戊四醇(PER)膨胀阻燃(IFR)体系中,测试其阻燃和力学性能;并利用热重、热分析-质谱及扫描电镜等方法探索其协效阻燃机理。结果表明:添加1%锡酸锌的PP/IFR体系LOI达30.2%,并且对力学性能影响较小;热分析表明加入锡酸锌使PP/IFR体系热降解过程中最大分解温度提高,最大失重速率降低,成炭量增加,炭层致密结实,部分离子流强度也有所降低,与IFR有很好的阻燃协同作用。     

新型有机硅阻燃成炭剂的热性能及成炭机理的研究

传统膨胀型阻燃剂(IFR)中的炭源为小分子醇类化合物,因此阻燃剂具有易吸湿、易迁移、与聚合物基体不相容等缺点。为了改进这些缺点,合成了一种新型的含有机硅的三嗪类大分子成炭剂(CA),将其与多聚磷酸铵(APP)复配成膨胀型阻燃剂用于聚丙烯(PP)阻燃。通过红外光谱、热失重分析、极限氧指数、垂直燃烧、锥形量热仪、扫描电子显微镜等手段研究了CA的热性能、燃烧性能、成炭机理以及APP与CA的配比对PP阻燃性能、热稳定性能的影响。结果表明,所合成的CA显示出较好的热稳定性和优异的成炭性,残炭率为25.6%(600℃)。另外,APP与CA在阻燃PP中具有协同阻燃作用;IFR的加入能大幅度降低PP阻燃体系的热释放速率和总释放热,有效地降低烟释放量及烟释放速率,提高PP的阻燃性能。     

氢氧化镧对聚丙烯膨胀阻燃体系性能影响

采用燃烧性能测试、热重分析、扫描电镜和力学性能测试等手段,分别研究了氢氧化镧对聚丙烯/磷酸密胺盐/季戊四醇(PP/MP/PER)复合材料阻燃性能和力学性能的影响。结果表明,添加氢氧化镧的PP/MP/PER复合材料的垂直燃烧指数均达到V0级别,当氢氧化镧添加量为0.5 %（质量分数,下同）时,复合材料的极限氧指数可达33.0 %,说明氢氧化镧能在一定程度上提高了PP的阻燃性能,是一种有效的阻燃协效剂。这可能是因为膨胀阻燃PP体系在燃烧过程中,氢氧化镧可与膨胀型阻燃剂反应形成网状结构、提高体系黏度,促进体系形成致密的炭层,提高体系的残炭量。研究还表明,在膨胀阻燃PP体系引入适量的氢氧化镧可在一定程度上提高体系的力学性能。     

新型磷-氮膨胀阻燃剂在改性聚丙烯中的应用研究

采用自制干法合成的磷-氮膨胀型阻燃剂(磷酸酯三聚氰胺盐,IFR)复配聚磷酸胺(APP)和聚四氟乙烯(PT-FE)阻燃改性聚丙烯(PP),利用极限氧指数法、垂直燃烧法分析了阻燃PP的燃烧性能,通过热重分析仪、傅里叶变换红外光谱仪、扫描电子显微镜和X射线光电子能谱对阻燃PP的热降解过程、燃烧性能、残炭结构进行了分析,并研究了燃烧过程中复配阻燃体系对PP的阻燃机理。结果发现,IFR、APP和PTFE之间具有明显的阻燃协效作用;当阻燃剂总添加量为24%(APP为6%、IFR为17.5%、PTFE为0.5%)(质量分数)时,阻燃PP的极限氧指数达到30.1%,垂直燃烧测试达UL 94V-0级;加入阻燃剂还能提高PP的热稳定性。     

基于胞苷酸阻燃剂的制备及其对PP阻燃性能的影响

为了提高膨胀阻燃剂(IFR)对于聚丙烯(PP)的阻燃效率,选择具有阻燃潜质的胞苷酸衍生物作为协效剂。胞苷酸与三缩水甘油基异氰尿酸酯反应形成阻燃微球,同时引入镍离子与磷酸基团反应成盐,以提高其热稳定性,得到基于胞苷酸镍的阻燃微球TC-Ni,通过红外光谱研究了其结构。将TC-Ni与膨胀阻燃剂(IFR)复合,通过熔融共混法制备阻燃PP复合材料。通过极限氧指数、垂直燃烧等研究了复合材料的阻燃性能,通过热失重分析测试其热稳定性,采用扫描电镜观察炭层结构。结果表明,添加17%IFR和1%TC-Ni可以使样品通过UL94 V–0级别,并且其LOI提高到29.2%。TC-Ni改善了PP/IFR形成的膨胀炭形态和完整性,使炭层表层炭致密,内层多孔,从而有效地提高了PP/IFR体系的阻燃效率。     

新型膨胀阻燃聚丙烯结构与性能研究

采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备了具有良好阻燃性能的膨胀阻燃聚丙烯(PP).研究了MPP/PEPA质量比和Cr2O3用量对PP阻燃和力学性能的影响.结果表明,MPP/PEPA质量比为3:2时,复配效果最好;添加少量的Cr2O3即可显著提高材料的阻燃性能.当MPP,PEPA,Cr2O3添加质量分数分别为12%,8%和2%时,阻燃PP的氧指数高达31.5%,且具有较好的力学性能.热失重(TGA)、扫描电镜(SEM)和Kissinger动力学分析表明添加Cr2O3可催化MPP/PEPA间的酯化反应,促进材料成炭,减缓材料的热降解速率,提高材料隔热、隔氧能力.     

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。