LH-1型催化剂催化乙烯聚合的性能

评价了LH-1型催化剂催化乙烯均聚合,乙烯-丙烯、乙烯-1-丁烯共聚合的性能.与国内工业化生产的催化剂进行对比,研究了LH-1型催化剂的粒径分布、催化活性、氢调敏感性.结果表明:LH-1型催化剂的粒径分布均匀,细粉含量少,且具有较高的氢调敏感性;在聚合温度80℃、压力0.8 MPa、氢气分压0.2 MPa的乙烯淤浆聚合工艺下聚合2h,LH-1型催化剂的活性较高,达5.36×104 g/g,优于对比催化剂;用LH-1型催化剂制备的高密度聚乙烯的堆密度较大,达0.350g/cm3,乙烯-丙烯、乙烯-1-丁烯共聚合性能好.     

新型高性能乙烯淤浆聚合Ziegler-Natta催化剂的开发

通过引入卤代醇类化合物制备了适用于乙烯淤浆聚合工艺的新型高性能Ziegler-Natta催化剂(简称GH催化剂)。采用分光光度计、扫描电子显微镜等表征了催化剂的组成、粒径和形态等;采用淤浆聚合法研究了催化剂的聚合性能,并与国产商业化催化剂(参比催化剂)进行了比较。结果表明:GH催化剂的活性达21.6 kg/g,聚乙烯堆密度达0.34 g/cm3,粒径≥75~830μm的聚乙烯粉料质量占聚乙烯粉料总质量的97.9%,且GH催化剂的氢调敏感性和其催化乙烯与1-己烯共聚合的性能均优于参比催化剂。     

乙烯淤浆聚合用Ziegler-Natta催化剂的制备及催化性能

通过加入新型给电子体制备了适用于乙烯淤浆聚合工艺的Ziegler-Natta催化剂。采用激光粒径分析仪、扫描电子显微镜、比表面吸附仪及X射线衍射仪分析和表征了催化剂的粒径、形态和物理结构等。采用乙烯淤浆聚合法研究了该催化剂的乙烯淤浆聚合性能,并与进口参比催化剂进行了比较。结果表明:在氢气分压为0.28 MPa、乙烯分压为0.45 MPa、反应温度为80℃、反应时间为2 h的条件下,催化剂活性达到21.3 kg/(g·h),聚合物堆密度达到0.34 g/cm3,粒径小于100μm的细粉含量为1.87%,催化剂的综合指标优于参比催化剂。     

MgCl2-BuOH/TiCl4催化剂催化乙烯聚合动力学

研究了MgCl2-正丁醇/TiCl4催化剂常压下催化乙烯聚合的性能和动力学行为.考察了n(Al)/n(Ti)、聚合温度、共聚单体浓度、氢气分压对催化剂性能的影响.研究表明:三乙基铝为助催化剂,n(Al)/n(Ti)为200,聚合压力为0.1 MPa,温度为50℃,聚合时间为2 h时,该催化剂具有较高的活性:聚合动力学行为平稳,活性衰减较慢,活性可达1 550.2 g/g;该催化剂具有良好的乙烯均聚合和共聚合性能以及氢调性能.     

气相聚丙烯催化剂CS-G1的性能研究及其工业应用

考察了CS-G1催化剂的组成、粒子形态、催化丙烯聚合的性能,并与同类型进口的CDi催化剂进行对比.结果表明:CS-G1催化剂钛含量高,粒径分布窄,具有良好的类球型形态;与CDi催化剂相比,CS-G1催化剂应用于Innovene气相法聚丙烯工业催化丙烯聚合活性和氢调敏感性降低,但制备的聚丙烯粉料颗粒形态好,细粉含量低,有...     

JK-1型催化剂在乙烯淤浆聚合工艺上的应用

研究了JK-1型催化剂在乙烯聚合中的工业应用情况,考察了使用JK-1型催化剂进行乙烯聚合过程中温度的变化,以及分别使用JK-1型催化剂和对比催化剂(简称催化剂A)生产的高密度聚乙烯(HDPE)的物理和力学性能。结果表明:工业装置上使用JK-1型催化剂时,全线生产过程平稳,装置工艺参数容易调整;JK-1型催化剂的氢调敏感性较好,活性比催化剂A提高30%;用JK-1型催化剂生产的HDPE 5000S粉末的堆密度高,密度稳定性较好,灰分明显小于用催化剂A生产的5000S,仅0.006%;用JK-1型催化剂制备的5000S达到了优级品的标准。     

高效MgCl2/SiO2复合载体型聚乙烯催化剂的研究

采用相同的工艺制备了两种不同的MgCl2/SiO2复合载体型Ziegler-Natta催化剂,考察了SiO2粒径对催化剂的形态结构及其催化乙烯聚合性能的影响,并利用BET测试仪和扫描电子显微镜(SEM)等对催化剂的形态和物性进行了表征。结果表明:加入小颗粒SiO2可以改善催化剂的颗粒形态和均匀程度,而且小颗粒SiO2制备的复合载体催化剂不仅具有较高的催化剂活性,还可使聚合产品的颗粒变得均匀,提高聚合物的堆密度,降低细粉含量,增强氢调敏感性。     

镁负载量对SiO_2/MgCl_2复合载体型Ziegler-Natta催化剂的影响

引入硅胶载体,与乙氧基镁在有机混合溶剂中共浸渍得到镁质量分数分别为5.00%,10.00%和15.00%的催化剂前驱体,与TiCl_4反应制得一系列SiO_2/MgCl_2复合载体型Ziegler-Natta催化剂。将所得催化剂用于常压乙烯均聚合、乙烯与1-己烯共聚合和氢调实验,比较不同催化剂活性和产物性能的差异,考察镁负载量对催化剂的影响。结果表明:镁负载量显著影响催化剂的孔结构和组成;镁质量分数为15.00%时,所得催化剂的Ti含量、比表面积以及β-MgCl_2相对含量均较高,其均聚合活性、整体共聚合活性最高,所得聚乙烯具有更高的相对分子质量和更宽的相对分子质量分布;同时,该条件下所得催化剂还具有很好的氢调敏感性。     

聚合温度对乙烯聚合用钒系催化剂FVC-01性能的影响

采用MgCl_2/AlCl_3复合载体负载钒化合物制备了乙烯聚合用催化剂FVC-01,以三异丁基铝为助催化剂,氢气为相对分子质量调节剂,研究了淤浆工艺中聚合温度对催化剂活性及聚合物性能的影响。结果表明:FVC-01解决了钒系催化剂对聚合温度敏感性高的问题,催化剂聚合性能稳定;聚合温度为82~84℃时,催化乙烯聚合的活性达5.22 kg/(g·h),聚乙烯的表观密度大于0.38 g/cm~3,细粉质量分数小于1.00%,相对分子质量分布(MWD)为16.5~21.5,较用钛系催化剂生产的聚乙烯的MWD宽,可在单反应器内开发宽MWD的聚乙烯。     

宽相对分子质量分布PE钛系催化剂的研究

合成了一种钛系催化剂,可以在单反应器内催化乙烯聚合得到宽相对分子质量分布的聚合物.该催化剂具有很好的乙烯聚合活性,最高可在4.1 kg/(g·h)以上.在催化乙烯聚合过程中,通过调整助催化剂用量,控制温度、氢分压等可以得到不同相对分子质量及其分布的聚乙烯树脂.     

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。