SBS/MMT共混物改性沥青性能的研究

利用苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与蒙脱土(MMT)制备了不同m(SBS):m(MMT)的共混物,探讨了共混物中m(SBS):m(MMT)对改性沥青物理机械性能、高温贮存稳定性、相形态及动态力学性能的影响。同时,对SBS/MMT用量和质量比相同的共混物改性沥青与直接改性沥青的性能作了对比分析。结果表明:利用SBS/MMT共混物对沥青进行改性在保持试样较好的低温性能的同时,能够明显提高沥青的高温贮存稳定性及高温动态力学性能,整体改性效果优于SBS/MMT直接改性沥青。     

动态硫化乙烯-乙酸乙烯酯共聚物/苯乙烯-丁二烯-苯乙烯嵌段共聚物复合改性沥青的性能

用乙烯-乙酸乙烯酯共聚物(EVA)和苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青,研究了EVA/SBS复合改性沥青动态硫化前后的软化点、针入度(25 ℃)、延度(5 ℃)及贮存稳定性,并用应变控制流变仪与光学显微镜分析了复合改性沥青的动态力学性能和相态结构.结果表明,动态硫化处理后,EVA/SBS复合改性沥青的延度和针入度下降,而软化点提高;随着硫黄用量的增加,EVA/SBS复合改性沥青的高温贮存稳定性提高,温度敏感性降低;随着EVA用量的增加,EVA/SBS复合改性沥青的高温贮存稳定性先提高后降低;当EVA质量分数为3%、硫黄质量分数为3%时,其对沥青的改性效果最佳;改性剂微粒与沥青的相容性和稳定性明显改善.     

SBS/MMT共混物改性沥青的稳定性

采用动态剪切流变仪(DSR)与光学显微镜(OM)从动态力学性能及相形态变化的角度研究了苯乙烯-丁二烯-苯乙烯嵌段共聚物与蒙脱土(SBS/MMT)共混物改性沥青的稳定性,同时通过高温贮存稳定性测试对其稳定性作了进一步分析,并对SBS/MMT共混物改性沥青与SBS单独改性沥青及SBS/MMT直接改性沥青的上述性能分别作了比较分析。结果表明,SBS/MMT共混物改性沥青的稳定性整体上较SBS单独改性沥青及SBS/MMT直接改性沥青均有一定程度的提高。     

聚苯乙烯改性沥青高温性能研究

通过反应共混技术制备了聚苯乙烯（PS）/苯乙烯-丁二烯-苯乙烯共聚物（SBS）改性沥青,研究了 PS 用量、反应剂硫磺（sulfur）对沥青高温贮存稳定性、黏度-温度特性和动态力学性能的影响。结果表明:通过反应共混改性所得到的改性沥青在高温贮存时,当 PS/SBS 不大于1/1时贮存样品上下层软化点差值小于2.5℃,贮存稳定性能得到了明显改善。对于沥青/PS/SBS/Sulfur 为100/3/3/0.15的体系,沥青的黏流活化能（Eη）从65kJ/mol 降低到了52.8kJ/mol;同时显著提高了沥青的高温复数模量和弹性,损耗角正切值（tanδ）在30～100℃范围内的变化小于10。     

动态硫化EVA/SBS复合改性沥青动态力学性能的研究

研究动态硫化乙烯-乙酸乙烯酯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青的动态力学性能,并与基质沥青和SBS改性沥青进行对比.结果表明,与基质沥青和SBS改性沥青相比,EVA/SBS复合改性沥青的复数模量和抗车辙因子明显增大、损耗因子明显减小,说明其高温弹性和高温抗车辙变形能力增强、温敏性显著下降;动态硫化EVA/SBS复合改性沥青的高温弹性、高温抗车辙变形能力和温敏性进一步改善.     

辐射接枝SBS的性能研究

采用旋转流变仪研究了苯乙烯-丁二烯-苯乙烯（sgs）嵌段聚合物接枝α-甲基丙烯酸（MAA）、甲基丙烯酸甲酯（MMA）接枝共聚物（SBS-g-MAA，SBS-g-MMA）的动态流变性能。结果表明：接枝共聚物的黏流活化能降低，温度敏感性降低；比较改性前后的共聚物的主曲线，接枝共聚物的相对分子质量分布变宽，在剪切应力作用下，黏度下降较快；接枝共聚物的相对分子质量分布变宽，接枝共聚物的抗氧化性增强。     

高温溶液法制备SBR的结构和性能研究

以正丁基锂（n-BuLi）为引发剂、醚类化合物为调节剂、环己烷／正己烷为溶剂,采用阴离子高温聚合工艺合成了溶聚丁二烯／苯乙烯橡胶（SSBR）。通过GPC、NMR分别测试了SSBR的相对分子质量及其分布和微观结构;并对硫化胶性能和门尼粘度进行了测定。考察了调节剂、温度等因素对SSBR的相对分子质量及其分布、共聚物微观结构、序列分布以及动态力学性能和物理机械性能的影响。研究结果表明：所用调节剂是有效的SSBR高温聚合调节剂,可很好地调节SSBR中的乙烯基含量,获得微观结构适中的中高乙烯基丁苯共聚物;n（调节剂）／n（Li）对聚合速率及共聚物的1,2-结构含量有明显的影响,但对共聚物的相对分子质量分布无明显影响;温度对共聚物的转化率及微观结构均有一定的影响。     

废旧轮胎橡胶粉/苯乙烯-丁二烯-苯乙烯嵌段共聚物/石油树脂复合改性沥青的制备及性能

以苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）、废旧轮胎橡胶粉和石油树脂制备复合改性沥青,并对复合改性沥青的储存稳定性、温度敏感性、高温流变性能、抗车辙性能和黏度等进行了考察。结果表明,复合改性沥青中,SBS、废旧轮胎橡胶粉及石油树脂的最佳质量分数分别为4.5%、14.0%和4.5%;石油树脂/SBS/废旧轮胎橡胶粉复合改性沥青具有较好的储存稳定性、温度敏感性和抗车辙性能。     

掺聚丙烯纤维的SBS改性沥青性能

以聚丙烯纤维（polypropylene fiber,PP）和苯乙烯-丁二烯-苯乙烯嵌段共聚物（styrenic block copolymers,SBS）为原料，采用高速剪切法制备聚丙烯/SBS复合改性沥青，SBS和PP改性剂掺量分别为7%和0.25%，与SBS掺量为7%的改性沥青做对比。并对沥青三大指标进行试验研究，通过动态剪切流变试验（dynamic shear rheological test,DSR）分析改性沥青的高温流变性能，通过弯曲蠕变试验（BBR）研究改性沥青的低温抗裂性能，采用扫描电镜分析器微观形貌。分析结果表明：掺聚丙烯纤维的SBS改性沥青基本性能最佳；高温性能优于SBS改性沥青；SBS改性沥青有较小的劲度模量(s)和较大的蠕变速率(m)，表示其低温抗裂性优良；扫描电镜显示改性沥青中改性剂分布均匀，有较好的相容性。     

填充白炭黑的闭孔海绵橡胶——发泡剂、温度、频率和应变对其结构和性能的影响

聚烯烃弹性体（POE）结构规整,无毒害成分,应用广泛。对乙烯-辛烯共聚物硫化胶的结构与性能关系的研究已日趋成熟。文中分析了填充沉淀法白炭黑的闭孔乙烯-辛烯共聚物硫化胶的动态力学特性,研究了发泡剂用量、填充剂用量、频率、温度对动态力学特性的影响。     

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。