不同相容剂对PP/PET合金性能的影响

以乙烯-丙烯酸甲酯共聚物接枝甲基丙烯酸缩水甘油酯(EMA-g-GMA),聚烯烃弹性体接枝GMA(POE-g-GMA)和聚丙烯接枝GMA (PP-g-GMA)为相容剂,采用熔融共混法制备了PP/聚对苯二甲酸乙二醇酯(PET)合金,并对PP/PET合金的性能进行了分析;研究了不同相容剂对PP/PET合金的加工性能、力学性能和微观形貌的影响。结果表明:在添加质量分数5%相容剂的情况下,PP/PET合金加工性能都得到了明显改善,POE-g-GMA可以显著地提高合金的韧性,而PP-g-GMA则可以有效地提高合金的刚性。     

苯乙烯在POE接枝GMA中的作用及其对增韧PBT效果的影响

采用苯乙烯(St)为辅助接枝单体,在聚烯烃弹性体(POE)上熔融接枝甲基丙烯酸缩水甘油酯(GMA),制备了POE-g-GMA,通过红外光谱表征证实了接枝反应的发生,考察了St的引入对POE-g-GMA接枝率、熔体流动速率以及POE-g-GMA增韧聚对苯二甲酸丁二醇酯(PBT)的影响。结果表明,在m(St)/m(GMA)为1时POE-g-GMA接枝率达到最大值,为1.057%;随着St用量的增加,接枝物的熔体流动速率持续降低;St的引入使POE相区尺寸明显减小,POE分散相与PBT基体间的相容性明显改善,共混物的冲击强度显著提高,PBT得到有效增韧。     

GMA接枝SEBS及其对PA 6的改性及增容

用双螺杆反应挤出法将甲基丙烯酸缩水甘油酯(GMA)接枝到氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)上(即SEBS-g-GMA)，研究引发剂过氧化二异丙苯用量、活性单体GMA用量对接枝率的影响；通过双螺杆挤出、共混，制备聚酰胺(PA)6／SEBS-g-GMA、PA 6／SEBS-g-GMA／SEBS合金，研究SEBS-g-GMA对合金体系的相容性影响及增韧作用，探讨了合金体系的形态结构和力学性能。     

POE-g-GMA的制备及其对纳米CaCO_3／PA66的增韧

采用熔融法制备乙烯-1-辛烯共聚物(POE)接枝甲基丙烯酸环氧丙酯(GMA),利用红外光谱对其结构进行表征。考察了GMA和过氧化二异丙苯(DCP)用量以及反应温度和反应时间对接枝率的影响,结果表明,GMA用量增加,接枝宰逐渐增大,熔体流动速率逐渐下降；隨着引发剂用量的增加,接技率也隨之增加；同时隨著反应温度和反应时间的变化,接枝率随之变化。然后采用熔融共混法制备了纳米CaCO_3／POE-g-GMA／PA66复合材科,研究了该体系的力学性能,结果表明,纳米CaCO_3和POE-g-GMA对PA66具有一定的增韧作用。     

熔融法制备EPDM-g-GMA及其对PEN脆韧转变的研究

利用Haake流变仪对(乙烯／丙烯／二烯)共聚物(EPDM)进行熔融接枝甲基丙烯酸缩水甘油酯(GMA),考察了单体、引发剂(DCP)用量对接枝率的影响。结果表明,随着DCP用量的增加,接枝率增大;随着GMA用量的增加,接枝率趋于一个平衡值。聚萘二甲酸乙二酯(PEN)／EPDM-g-GMA共混物的脆韧转变主要受温度和EPDM-g-GMA用量的影响,增加EPDM-g-GMA用量可以降低PEN／EPDM-g-GMA共混物的脆韧转变温度。     

相容剂对PC/R-PET合金的影响

研究了不同相容剂(乙烯-丙烯腈-丁二烯-甲基丙烯酸缩水甘油酯共聚物、苯乙烯-丙烯腈-甲基丙烯酸缩水甘油酯三元共聚物、乙烯-辛烯弹性体接枝甲基丙烯酸缩水甘油酯、乙烯-丙烯酸甲酯-甲基丙烯酸缩水甘油酯三元共聚物)及其添加量对聚碳酸酯(PC)/回收聚对苯二甲酸乙二醇酯(R-PET)合金的力学性能以及稳定性的影响。结果表明,加入带有反应性官能团的相容剂之后,可以有效抑制PC/PET的酯交换反应,从而提高制品的力学性能和热稳定性。不同的相容剂,反应效率不同,相对而言,甲基丙烯酸缩水甘油酯(GMA)官能团的反应活性高于马来酸酐(MAH),而且随着GMA含量的增加,对于相态的优化以及性能更有优势,但是并不会随着GMA的增加而一直增加。相对而言,苯乙烯-丙烯腈-丁二烯-甲基丙烯酸缩水甘油酯(SBG)核-壳结构的弹性体在刚-韧平衡上更为均衡。     

相容剂对PA6/POE力学性能和微观结构影响

转矩流变仪中熔融法制备了苯乙烯(St)和甲基丙烯酸缩水甘油酯(GMA)或甲基丙烯酸羟乙酯(HEMA)分别接枝乙烯-辛烯共聚物(POE),并将接枝物用于聚酰胺6(PA6)增韧改性.结果表明:2种接枝物POE-g-(GMA-co-St)和POE-g-(HEMA-co-St)的最佳反应加工时间分别为8.0 min和10.0 min,二者均能明显改善PA6与POE之间的相容性,但是前者增韧效果更好,其改性共混物力学性能更优.     

POE熔融接枝甲基丙烯酸缩水甘油酯的研究

采用同向双螺杆挤出机熔融法制备乙烯-1-辛烯共聚物接枝甲基丙烯酸缩水甘油酯（POE-g-GMA），利用红外光谱法和化学滴定法对接枝物进行表征及接枝率的测定。考察了GMA／St（苯乙烯）、St、引发剂用量以及反应温度和螺杆转速对接枝率的影响。结果表明。随着GMA／St用量、引发剂用量的增加。POE-g-GMA的接枝率随之增大。而熔体流动速率下降；St的加入有效地提高了GMA的接枝率；随着反应温度提高接枝率提高；螺杆转速提高接枝率下降。     

接枝弹性体增韧吹塑用PET材料的性能

为提高吹塑用聚对苯二甲酸乙二酯(PET)的冲击韧性，选用接枝甲基丙烯酸缩水甘油酯的聚烯烃弹性体(POE-g-GMA)与接枝马来酸酐的聚烯烃弹性体(POE-g-MAH)对吹塑用PET材料进行共混改性，研究两种不同官能团的接枝弹性体添加量对吹塑用PET材料增韧效果及材料其它性能的影响。结果表明，两种接枝弹性体的加入都能提高吹塑用PET材料的韧性，缺口冲击强度分别在POE-g-GMA质量分数为10%与POE-g-MAH质量分数为15%时达到最大，而后随着添加量的增加略有下降，扫描电子显微镜观察共混试样冲击断面微观形貌均表现明显的韧断特征；同时接枝弹性体的加入会导致材料拉伸强度降低，当接枝弹性体质量分数为5%和10%时，POE-g-MAH增韧的材料拉伸强度较低；差示扫描量热测试表明，两种接枝弹性体的添加使材料结晶性能提高，POE-g-GMA与POE-g-MAH质量分数分别为10%与15%时结晶性能最好，熔融温度最高，此时弹性体与PET相容性最好，间接证明了材料缺口冲击强度的变化；熔体流动速率测试表明，随着两种接枝弹性体添加量的增加，材料的流动性呈下降趋势。综合改性材料的力学性能，同时考虑实际生...     

超韧阻燃PBT材料的制备与性能研究

以超韧阻燃聚对苯二甲酸丁二醇酯(PBT)为研究对象,探讨了弹性体乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PTW)增韧体系、聚烯烃接枝甲基丙烯酸缩水甘油酯(POE-g-GMA)增韧体系以及核壳聚合物甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)/聚碳酸酯(PC)复合增韧体系等对PBT材料力学性能与阻燃性能的影响,同时探讨了十溴二苯乙烷与溴化环氧两种阻燃剂对PBT材料阻燃性能、力学性能以及产品色相等方面的影响.结果表明,MBS/PC复合增韧体系增韧效果最好,材料拉伸强度与弯曲强度保持率最高,同时对材料的阻燃性能的影响也最小;溴化环氧阻燃体系材料弯曲强度更高,拉伸强度与缺口冲击强度保持率更好,同时产品色相白度更高,其阻燃效率相对略低.     

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.