聚乙烯蜡溶液接枝马来酸酐工艺优化的研究

以BPO为引发剂、聚乙烯蜡（PEW）和马来酸酐（MAH）为反应物，采用溶液法合成聚乙烯蜡接枝马来酸酐（PEW-g-MAH），使用L。（3。）正交实验表考察不同反应温度、时间、MAH和BPO用量对PEW-g-MAH接枝率的影响。红外分析表明MAH已经接枝到PEW分子链上；在PEW用量为10g、MAH为1．40g、BPO为0-10g、温度100℃、反应时间60min条件下，可得到接枝率为2．95％的PEW—g—MAH。     

MAH溶液法接枝SBS的研究

采用马来酸酐（MAH）作为接枝单体,对苯乙烯—丁二烯—苯乙烯三嵌段共聚物（SBS）进行溶液接枝。研究了反应温度、反应时间、马来酸酐用量、引发剂种类及用量对接枝率的影响。得到最佳反应条件为：m（SBS）/m（MAH）/m（BPO）/m（溶剂）=100：10：0.8：400,反应温度75℃。反应时间3 h;红外光谱图证实了接枝物的生成。     

聚丙烯（PP）／黏土复合材料熔融剂的研究

以马来酸酐（MAH）等为单体接枝聚丙烯作为聚丙烯（PP）／黏土复合材料熔融剂,考察了马来酸酐用量、引发剂过氧化苯甲酰（BPO）用量、反应时间、温度等因素对产物接枝率的影响,并通过红外光谱图对PP-g-MAH进行表征。结果表明,当m（PP）：m（复配单体）：m（BPO）=10．0：2．0：0．6、反应温度控制在120℃左右、复配单体为马来酸酐／苯乙烯时,熔融剂PP-g-MAH的接枝率可获得较大值3．9％。实验同时表明,反应时间对接枝率的影响不大;苯乙烯的加入对接枝率有较大的影响,与普通单体单一马来酸酐相比,加入苯乙烯的接枝率明显提高。     

塑料涂料用马来酸酐接枝氯化聚丙烯的合成与性能

以甲苯为溶剂、过氧化苯甲酰(BPO)为引发剂、马来酸酐(MAH)为接枝单体,对氯化聚丙烯(CPP)进行接枝改性.考察了引发剂和接枝单体用量、反应温度、反应时间以及原料的含氯量对接枝率的影响,并对改性产物进行了傅立叶红外光谱表征.结果表明,氯化聚丙烯成功地接枝上马来酸酐,反应条件和原料的含氯量会影响接枝率,优化的工艺条件为:m(BPO)/m(CPP)=0.04,m(MAH)/m(CPP)=1.1,反应温度为100 ℃,反应时间为3 h.涂料性能测试结果说明,改性产物在部分酮酯类溶剂中的溶解性能优良,对多种塑料材料有良好的附着性能,而附着力的大小受到接枝率的直接影响.     

嵌段SBS接枝马来酸酐及马来酸盐的合成及性能

本文以溶液法合成SBS接枝马来酸酐（MAH），控制不同反应时间、反应温度及MAH用量，得到不同接枝率的产物，用红外光谱及反滴定法分别定性定量表征了接枝率，结果显示：随反应时间、反应温度和马来酸酐用量的增加，接枝率呈不同增加趋势，其中反应温度对产物接枝率的影响最为显著。分别用NaOH、CaCl2、LaCl3将SBS接枝马来酸酐(sBS-g-MAH)离子化，得到SBS接枝马来酸盐离聚物。其耐溶剂性能、吸水性能及对极性基体的粘合性能随离子化而发生变化。离聚物呈现更好的吸水性能及耐溶剂性能。     

MAH/MMA共接枝PEW/有机蒙脱土复合材料的制备与耐热性研究

用熔融接枝法对有机蒙脱土(OMMT)/聚乙烯蜡(PEW)进行马来酸酐(MAH)、甲基丙烯酸甲酯(MMA)双单体共接枝改性,考察了MAH含量、MMA含量、OMMT含量等因素对PEW的接枝率的影响.结果表明:当MAH、MMA、OMMT质量含量分别为5%、3%、10%时,得到PEW的接枝率为3.5%左右.热重分析(TGA)、差示扫描量热(DSC)的结果表明改性PEW/有机蒙脱土复合材料的熔融温度和热分解温度比PEW分别高7.7℃和23.4℃,热重与红外联用(TGA-FTIR)分析表明在183.24℃时,改性PEW/有机蒙脱土复合材料开始分解.制得的改性PEW/有机蒙脱土复合材料具有较好的耐黄变性能,在220℃下挤出加工不变色.     

氯化聚丙烯接枝马来酸酐的合成研究

考察了马来酸酐（MAH）用量、引发剂（BPO）用量、反应温度和反应时间对氯化聚丙烯接枝马来酸酐（CPPgMAH）中接枝率和接枝效率的影响。结果表明m（MAH）：m（CPP）=0．28时，接枝率和接枝效率较高；随着引发剂过氧化苯甲酰（BPO）用量的增大，接枝率和接枝效率也随之增大；提高反应温度，可以提高接枝效果，适宜的反应温度和反应时间分别为100℃、1．5h。     

嵌段SBS接枝马来酸酐及马来酸盐的合成及表征

用溶液法合成嵌段SBS接枝马来酸酐(MAH)，控制反应时间、反应温度及MAH用量，得到不同接枝率的产物。用红外光谱及反滴定法定性定量表征了接枝率。结果表明：随反应时间、反应温度和马来酸酐用量的增加，接枝率呈不同增加趋势，其中反应温度对产物接枝率的影响最为显著。分别用NaOH、CaCl2、LaCl3将SBS接枝马来酸酐(SBS—g—MAH)离子化，得到SBS接枝马来酸盐离聚物(SBS—g—MAM)。其耐溶剂性能、吸水性能及对极性基体的粘合性能随离子化程度而发生变化，离聚物具有更好的吸水性及耐溶剂性能。     

马来酸酐接枝聚乙烯蜡微粉的制备工艺及其在粉末涂料中的应用研究

首先以二甲苯（PX）为溶剂,聚乙烯蜡（PEW）为接枝主链,过氧化苯甲酰（BPO）为引发剂,将马来酸酐（MAH）接枝到PEW上,制备PEW⁃g⁃MAH接枝料;其次,以丙酮为沉淀剂,使其析出沉淀;最后,对上述混液进行抽滤、干燥、研磨、筛分,得到PEW⁃g⁃MAH微粉。利用傅里叶变换红外光谱仪（FTIR）和激光衍射粒度分析仪（LDPA）对产物结构进行表征,通过附着力测试仪对产物进行附着力性能测定。通过考察单因素与设计正交试验,探究反应最佳的工艺条件。结果表明,当PEW的含量为10 g,此时MAH的最佳含量为0.6 g,最佳反应温度为110 °C,引发剂的最佳含量为0.2 g,最佳反应时间为4 h。该条件下,MAH的接枝效率最高,为58.57 %,接枝率为3.51 %,平均粒径为15.54 µm,附着力为0级。因此,该PEW⁃g⁃MAH微粉在粉末涂料中具有较好的应用潜力。     

硅烷/马来酸酐混合接枝高密度聚乙烯的制备与应用

以硅烷(VTMS)、马来酸酐(MAH)为单体,过氧化二异丙苯(DCP)为引发剂,制备硅烷/马来酸酐接枝高密度聚乙烯(PE-HD),研究引发剂DCP、单体VTMS和MAH含量对接枝产物性能的影响,用红外光谱(FTIR)对接枝产物进行分析,并将接枝产物作为相容剂添加到复合材料中。结果显示：VTMS和MAH能够在PE-HD上进行接枝,随着DCP、VTMS和MAH含量的增加,接枝产物的接枝性能先增加后减小;和VTMS和MAH单种单体接枝PE-HD比较,硅烷/马来酸酐接枝高密度聚乙烯(MAH/VTMS -g-PE-HD)能够显著提高复合材料的力学性能。     

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。