阻燃剂增韧剂玻璃纤维对挤出型薄壁阻燃增强PC材料的阻燃等级力学性能和抗翘曲性能的影响

研究了磷酸酯阻燃剂、全氟丁基磺酸钾、有机倍半硅氧烷类阻燃剂、溴代三嗪、六苯氧环三磷腈5种阻燃剂对阻燃增强聚碳酸酯(PC)材料薄壁阻燃性能的影响;研究了MBS、ABS高胶粉、EMA类弹性体3种增韧剂对阻燃增强PC材料力学性能的影响;研究了PC专用普通短切玻璃纤维、PC专用扁平短切玻璃纤维对阻燃增强PC材料抗翘曲性能的影响。实验表明,六苯氧环三磷腈对增强阻燃PC薄壁阻燃效率比溴代三嗪、磷酸酯阻燃剂、有机倍半硅氧烷类阻燃剂和全氟丁基磺酸钾要好,当六苯氧环三磷腈添加量为7.5wt%,阻燃增强PC材料的阻燃等级可达到UL 94 0.75 mmV-0等级;与ABS高胶粉和MBS相比,EMA类弹性体对阻燃增强PC材料的综合力学性能更好,当EMA类弹性体的添加量为2 wt%时,阻燃增强PC材料的韧性最好;PC专用扁平短切玻璃纤维对挤出板抗翘曲性能比PC专用普通短切玻璃纤维要好。     

聚碳酸酯用有机硅阻燃剂的开发及应用研究

以新开发的有机硅聚合物为阻燃剂,应用于聚碳酸酯(PC)的阻燃改性,对比考察了自制有机硅阻燃剂和国外有机硅阻燃剂对PC的阻燃性能、力学性能和加工性能的影响。结果表明,添加6%的自制有机硅阻燃剂,PC的氧指数提高到32. 5%,阻燃等级达UL94 V-0级,阻燃效果跟国外产品相当;同时,自制有机硅阻燃剂可提升材料的断裂伸长率、冲击强度,可明显改善PC的加工流动性。另一方面,添加自制有机硅阻燃剂后,PC的拉伸强度和弯曲强度有所下降,但性能保持率均在90%以上。当添加量为6%时,PC的综合性能最佳。     

耐热阻燃ABS/PBT合金的性能研究

以十溴二苯乙烷、三(三溴苯基)氰尿酸酯(溴代三嗪)和溴化环氧为阻燃剂、三氧化二锑为阻燃协效剂,对ABS/PBT合金进行阻燃改性,并在阻燃合金体系中引入聚碳酸酯(PC)协同阻燃及提高耐热性能。考察阻燃剂种类、PC含量和PBT含量对阻燃ABS/PBT合金的力学性能、耐热性能及阻燃性能的影响。结果表明,采用溴代三嗪作为阻燃剂制备的ABS/PBT合金综合性能较好;PC的引入可明显提高合金的力学性能和耐热性能,降低溴系阻燃剂及阻燃协效剂的添加量,但会导致合金流动性下降;随着PBT含量的提高,合金的拉伸性能、弯曲性能及流动性提高,冲击性能及热变形温度(HDT)稍有下降。     

满足苛刻阻燃要求的聚碳酸酯材料的研制

选用全氟丁基磺酸钾、溴代三嗪等阻燃剂,通过复配或单独使用的方式构成不同的阻燃体系,采用双螺杆挤出机共混改性技术研究了不同阻燃体系对聚碳酸酯(PC)材料力学性能及阻燃性能的影响.结果表明:制备的阻燃PC材料可达到垂直燃烧V-0@0.8 mm且灼热丝起燃温度为875℃;同时,材料的缺口冲击强度＞20 kJ/m2,热变形温度...     

无卤阻燃增强增韧PBT研制

为改善聚对苯二甲酸丁二酯(PBT)材料易燃、韧性差等缺点,研制出无卤阻燃增强增韧PBT材料。对比了传统含卤阻燃剂与新型无卤阻燃剂对PBT阻燃性能的影响,并利用氮–磷系无卤阻燃剂HT–202A、玻璃纤维、增韧剂SWR–6B对PBT进行改性,研究了阻燃剂、玻璃纤维、增韧剂对PBT阻燃性能以及力学性能的影响。结果表明,无卤阻燃剂在与含卤阻燃剂含量相当的情况下,可以使PBT阻燃性能达到V–0级;在玻璃纤维含量为30%,阻燃剂HT–202A含量为16%,增韧剂SWR–6B添加量为5%时,PBT材料的阻燃性能达到V–0级,拉伸强度达到101 MPa,弯曲强度达到145 MPa,缺口冲击强度达到9.5 kJ/m~2,综合性能优异。     

不同溴系阻燃剂在阻燃ABS中燃烧行为与热行为

将四种不同的溴系阻燃剂十溴二苯乙烷(DBDPE)、溴化环氧(BEO)、溴代三嗪(BrN)、四溴双酚A (TBBA)在溴素质量分数10%条件下与三氧化二锑复配,然后加入到丙烯腈-丁二烯-苯乙烯塑料(ABS)中制备阻燃ABS材料,研究了这四种溴系阻燃剂阻燃ABS的燃烧行为和阻燃剂热行为之间的关系。结果表明,对于添加阻燃剂DBDPE和BEO的ABS试样,当其厚度为1.5,2 mm时,垂直燃烧阻燃等级只能达到V–2级,在锥形量热测试中,燃烧前期的热释放速率(HRR)和总热释放量(THR)也都高于添加阻燃剂BrN和TBBA的ABS试样;对于添加阻燃剂TBBA的ABS试样,当其厚度为1.5 mm时,垂直燃烧阻燃等级就可以达到V–0级,但是在锥形量热测试中,THR和HRR峰值(PHRR)较高;对于添加阻燃剂BrN的ABS试样,当其厚度为1.5 mm时,垂直燃烧阻燃等级可以达到V–0级,在锥形量热测试中,THR和平均有效燃烧热都低于其它阻燃ABS试样,这与四种阻燃剂的初始分解温度和分解速率有很大的关系,DBDPE和BEO初始分解温度高,TBBA初始分解温度低,但是分解速率快,BrN的初始分解温度高于TBBA,低于DBDPE和BEO,而分解速率较TBBA慢,所以整体表现的阻燃效果最佳。     

联枯在阻燃改性高抗冲聚苯乙烯产品中的应用研究

主要对联枯(DMDPB)在阻燃改性高抗冲聚苯乙烯材料当中的应用进行研究。结果表明,在溴代三嗪与三氧化二锑阻燃体系当中,联枯可以显著增加溴系阻燃剂的阻燃效率。当添加0. 8%的联枯时可在原配方当中减少3. 5%的溴代三嗪和1%的三氧化二锑,也可使材料能够到达UL 94 V0的阻燃等级。同时,联枯的加入对材料的物理机械性能和加工性能的影响较小,可以较好地降低阻燃苯乙烯材料的成本,具有较好的应用前景。     

耐低温高抗冲阻燃PC基LDS材料研制

以聚碳酸酯(PC)为基材,含硅树脂、不同MBS树脂为抗冲击改性剂,磺酸盐、抗滴落剂、溴化物为阻燃剂,研究了抗冲击改性剂和阻燃剂的协同配合对改善PC基激光直接成型(LDS)材料低温冲击强度和阻燃性能的影响。结果表明,含硅树脂含量超过70%时,能明显改善PC材料的低温抗冲击性能,但材料成本高。MBS EXL2690含量超过4%后,能明显改善PC材料的低温抗冲击性能,但MBS EXL2690用量一旦超过2%,磺酸盐、含氟抗滴落剂、含硅树脂组成的复合阻燃体系就很难使PC材料达到V0级。含硅MBS S–1含量超过5%,将会明显改善PC材料的低温冲击强度。然而当含硅MBS S–1含量一旦超过3.3%,增加阻燃剂用量很难达到阻燃V0级。选用更高硅含量、更大粒径的MBS S–2,其低温抗冲击性能突变点在4.4%左右,在该用量下配合磺酸盐复合阻燃体系能达到V1级。并用0.32%～0.47%溴化物,最终获得–30℃低温冲击强度大于600 J/m和阻燃级别达V0级的PC基LDS材料。此外,对阻燃剂相互配合机理做了解释。     

磷、溴阻燃剂在PC/ABS合金中的应用

对阻燃PC／ABS合金所用的阻燃剂进行了对比试验。结果表明。当PC／ABS质量比为7：3时，添加阻燃PC／ABS合金量的13％左右的溴系阻燃剂，可使材料的阻燃性能达到UL-94 V-0级（1．6mm）；磷酸酯系阻燃剂由于对ABS的阻燃效果不好，只有在材料中PC质量分数大于70％时，才有阻燃效果；用溴-磷酸酯系阻燃剂，即使在材料中PC质量分数为50％时，也能达到UL-94 V-0级（1.6mm），说明磷与溴在PC／ABS合金中有协效作用，将磷酸酯系阻燃剂与溴系阻燃剂复配使用．在阻燃PC／ABS合金中．亦有类似的效果。     

环保型溴系阻燃剂在ABS复合材料中的应用

分别采用十溴二苯乙烷(DBDPE)、四溴双酚A(TBBA)、溴代三嗪(Br N)为阻燃剂和三氧化二锑、氢氧化铝、硅酮粉、抗滴落剂等协效阻燃剂复配,与丙烯腈–丁二烯–苯乙烯塑料(ABS)通过熔融共混挤出制备阻燃ABS复合材料,对比了这3种阻燃剂对复合材料阻燃性能、力学性能、熔体流动性能和热性能的影响。结果表明,添加质量分数为8%的DBDPE即可使ABS复合材料垂直燃烧等级达到V–0级,热变形温度达到74.3℃,但DBDPE对复合材料拉伸、冲击性能及熔体流动性能有较大的负面影响;当3种阻燃剂质量分数均为12%时,添加Br N的复合材料的垂直燃烧等级达到V–0级,缺口冲击强度和热变形温度最高,分别为27.0 k J/m2和74.7℃,热稳定性最好,但拉伸和弯曲强度较低,在相同阻燃剂用量下,添加TBBA的复合材料拉伸、弯曲强度和MFR最大,分别为41.6,60.5 MPa和22.3 g/10 min,但其垂直燃烧等级仅为V–1级。     

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。