限定几何构型茂金属催化剂催化乙烯/1-己烯共聚研究

以自制的限定几何构型茂金属催化剂为主催化剂,甲基铝氧烷为助催化剂,对乙烯/1-己烯共聚性能进行研究,考察溶剂、Al与Zr物质的量比、聚合温度、聚合压力和共聚单体浓度等工艺条件对催化剂活性以及聚合物性能的影响。确定乙烯/1-己烯共聚合的工艺条件为:以正庚烷为溶剂,Al与Zr物质的量比为700~1 000,聚合温度(100~120)℃,聚合压力(1.2~2.0)MPa,优选1-己烯浓度为(0.8~1.8)mol·L~(-1)。     

一种Ziegler-Natta载体催化剂用于乙烯淤浆聚合的研究

对载体型催化剂进行乙烯淤浆聚合,研究了催化剂的乙烯聚合动力学,分析了聚合温度、压力,助催化剂及氢气加入量对聚合结果的影响.研究结果表明,最佳聚合条件为:聚合时间2 h,聚合温度80℃,聚合压力0.83MPa,Al/Ti比(物质的量比)115,H2/C2H4比(压力比)0.52.在此条件下,催化剂具有较高的催化效率,聚合物形态较好,表观密度较高,流动性很好.     

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.     

双核茂金属催化剂催化乙烯／1-己烯共聚合

合成了[CpTiCl2]2 {μ,μ-[(Me2Si)2 (η5-C5H3)2]}双核茂金属化合物,用1H NMR和IR分析进行了表征.合成的化合物经硅胶作载体负载,以MAO作助催化剂,催化乙烯/1-己烯共聚合.考察了茂金属用量,茂金属与硅胶/MAO处理温度,MAO的用量对负载催化剂的影响,以及1-己烯用量对聚合产物的影响.反应温度65℃,在1-己烯浓度为0.25 mol·L-1条件下共聚活性可达4.01×106 gPE/mol Ti·h,催化所得聚乙烯的相对分子质量分布为7.32,1-己烯插入率8.45%.     

新型高氢调敏感性乙烯淤浆聚合用催化剂的制备

制备了一种新型高氢调敏感性乙烯淤浆聚合用催化剂(简称SEL催化剂)。考察了SEL催化剂的组成、粒子形态,催化乙烯均聚合与共聚合的性能,以及用其制备的聚乙烯的性能,并与商业化的同类型进口催化剂(简称参比催化剂)进行了对比。结果表明:SEL催化剂中钛含量高而镁含量低,粒径分布窄,颗粒形态规整;SEL催化剂催化乙烯聚合时氢调敏感性好,氢气分压为0.48 MPa,乙烯分压为0.25 MPa时,聚乙烯熔体流动速率达226.10g/10 min;SEL催化剂催化乙烯与1-己烯共聚合的性能和聚乙烯粉料中细粉含量等均优于参比催化剂。     

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。     

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。     

双核茂金属催化剂催化乙烯／1-己烯共聚合

制备[CpTiCl2]2{μ,μ-[(Me2Si)2(η5-C5H3)2]}双核茂金属化合物,用1H NMR和IR分析进行了表征.合成的化合物经硅胶作载体负载,以MAO作助催化剂,催化乙烯/1-己烯共聚合.考察了茂金属用量,茂金属与硅胶/MAO处理温度,MAO的用量对负载催化剂的影响,以及己1烯-用量对聚合产物的影响.反应温度65℃,在1-己烯浓度为0.25mol/L条件下共聚活性可达4.01× 106gPE/molTi·h,催化所得聚乙烯的相对分子质量分布为7.32,己1烯-插入率8.45.     

乙烯和/或1-丁烯与丙烯共聚合的工业化研究

分析了Sphripol-Ⅱ环管工艺引入丙烯、乙烯及1-丁烯共聚单体后的聚合特性。引入乙烯后催化剂活性增加,氢调敏感性变差。引入1-丁烯后,催化剂活性变化不大,链转移速率增加,需降低H2用量以确保无规共聚PP的熔体流动速率合格。引入乙烯和1-丁烯的三元共聚合催化剂活性提高,氢调敏感性与乙烯和丙烯的二元共聚合时相当;因闪蒸线蒸汽压力的限制,装置负荷降低30%;控制环管反应器内淤浆中可溶物的含量,调整反应温度为60.0℃,乙烯质量分数≤2.5%;控制汽蒸器内温度低于105.0℃,避免低分子物料熔融黏附在汽蒸器表面及干燥器表面。     

广州乙烯公司聚乙烯装置投产

广州乙烯股份有限公司聚乙烯装置为10万t/a全密度聚乙烯装置,采用UCC公司的Unipol低压气相本体流化床聚合工艺,以丁烯-1或己烯-1为共聚单体,使用铬系和钛系三类(M、S、F)催化制,生产熔体流动速率为0.1～125g/10min的均聚、共聚产品。运行条件温和,无预聚合,不用溶     

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。