宽峰或双峰分布两段聚合聚乙烯树脂性能研究

用两段淤浆聚合工艺合成了具有宽峰或双峰相对分子质量分布的高密度聚乙烯（HDPE）／（乙烯／丁烯-1）共聚树脂的反应釜共混聚合物。随着丁烯-1用量的增加，共混物的密度、熔点、结晶度、拉伸屈服应力减小，而断裂伸长率增加。随着高相对分子质量共聚物的含量增加，熔点、密度、结晶度减小，相对分子质量分布的双峰特性也更明显。通过调整两段聚合物的熔体流动速率、两段聚合物之比来控制相对分子质量大小及其分布。控制第一段小分子数目，增加第二段相对分子质量或减小密度可获得最大耐环境应力开裂性能。     

聚乙烯气相制备工艺及其过程的数值方程表达

基于乙烯、1-丁烯、1-己烯的共聚合,研究了共聚单体与乙烯摩尔比、氢气与乙烯摩尔比、温度等对聚合物熔体流动速率、密度和催化剂活性的影响规律,并建立了聚乙烯制备过程的数值方程表达式。结果表明：共聚单体与乙烯摩尔比与聚合物的密度表现为负相关趋势,而与催化剂活性表现为正相关趋势,在共聚单体与乙烯摩尔比为0.08时,采用1-丁烯为共聚单体的催化剂活性为4 250 g/g,采用1-己烯为共聚单体的催化剂活性为4 780 g/g;氢气对熔体流动速率的影响最显著,可以作为熔体流动速率的有效调节控制因素,共聚单体与乙烯摩尔比则是调节聚合物密度的有效因素,该方程可以用于指导聚乙烯的制备过程控制。     

高强度薄膜专用HDPE的生产

在全密度聚乙烯装置上采用Unipol气相法工艺,以1-丁烯为共聚单体生产高强度薄膜专用高密度聚乙烯(HDPE)DGDB6097。DGDB6097的熔体流动速率(负荷21.6 kg)为7.00~13.00 g/10 min,密度为0.945~0.951g/cm3,拉伸屈服应力大于或等于19 MPa,拉伸断裂应力大于或等于23 MPa,断裂标称应变大于或等于500%。与相同工艺生产的普通薄膜专用线型低密度聚乙烯相比,DGDB6097的密度高、拉伸强度大;与国内市场常见的高强度薄膜专用HDPE DGDA6098相比,DGDB6097的力学性能、结晶性能、相对分子质量及其分布以及其薄膜的各项性能相当。加工应用表明,DGDB6097的加工性能和薄膜力学性能均满足用户要求。     

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     

1-己烯共聚与1-丁烯共聚LLDPE的性能对比

通过对1-己烯共聚线型低密度聚乙烯(LLDPE)与1-丁烯共聚LLDPE的分析对比,研究了1-己烯共聚与1-丁烯共聚LLDPE的性能差别。结果表明:在密度和熔体流动速率接近的情况下,1-己烯共聚LLDPE的共聚单体摩尔分数低于1-丁烯共聚LLDPE;1-己烯共聚LLDPE的片晶厚度大于1-丁烯共聚LLDPE,且片晶尺寸分布更窄;在快速形变速率情况下,1-己烯共聚LLDPE与1-丁烯共聚LLDPE树脂的拉伸性能差别更为明显;1-己烯共聚LLDPE流延膜的拉伸屈服应力、拉伸断裂应力、撕裂强度、落镖冲击强度及光学性能均高于1-丁烯共聚LLDPE。     

最新专利文摘

聚乙烯管材树脂1种聚乙烯管材树脂由质量分数44%～55%高相对分子质量聚乙烯和45%～56%低相对分子质量聚乙烯组成。高相对分子质量聚乙烯为密度0.913～0.923 g/cm~3线型低密度聚乙烯,熔体流动速率0.02～0.20 g/10 min(190℃,21.6 kg下);组成低相对分子质量聚乙烯的高密度聚乙烯密度至少为0.969 g/cm~3,且其熔体流动速率大于100 g/10 min;其中树脂密度(D)和低相对分子质量聚乙烯质量分数(P1)之间关系定义为(0.055P1+0.916)相似文献   

小资料

扬子石油化工公司塑料厂生产的HDPE 6200 B是吹塑共聚级牌号,密度为0.959g/cm~3,MI为0.40g/10min;6100M是专门用于生产管材的产品。它是乙烯与1-丁烯共聚产物,1-丁烯含量为2.3%,熔体     

PE100级管材专用HDPE树脂的开发

采用 Innovenes 工艺,双环管淤浆法,1-已烯为共聚单体开发生产了 PE100级管材专用高密度聚乙烯(HDPE)树脂PN049-030-122,分析了其结构、力学性能及加工应用情况,并与国内外同类产品进行了对比.HDPEPN049-030-122的熔体流动速率为0.290～0.300 g/10 min,密度为0.949g/cm3,拉伸弹性模量达1 100 MPa以上,简支梁缺口冲击强度大于30 kJ/m2,各项性能达到指标要求,相对分子质量分布曲线呈双峰.     

新型茂金属高支化聚乙烯产品的结构及性能研究

采用核磁共振分析仪、差式扫描量热仪,研究了不同碳链长度极低密度聚乙烯树脂(PE-VLD)产品的支化组成分布和熔融结晶性能;分别选取了平均序列长度、相对单体分布、共聚单体竞聚率进行聚合特性分析;运用自成核退火热分级(SSA)处理,讨论了晶片厚度(L)、相对支化度(S)、结晶度(X_c)等结晶特性。结果表明,密度为0.912g/cm~3、熔体流动速率为1.0g/10min的PE-VLD产品,以己烯为共聚单体(C6)制备的产品中共聚单体含量、S低于以丁烯为共聚单体(C4)产品;而X_c、L则要高于C4产品。     

冰箱级HDPE

美国陶氏公司新推出具有高流动性冰箱级 H D PE树脂 ,商品名为Dow lex IP-51。其适用于温度低达 -1℃的食品硬包装 ,专用于注射成型大型冰淇淋薄壁容器。新树脂性能如下 :密度 0 .947g/ cm3 ,熔体流动速率 50 g/1 0 m in,拉伸强度 1 0 .5MPa,断裂伸长率 3 0 % ,艾佐缺口冲击强度 3 2 J/ m ,弯曲模量 840 MPa。　　据该产品市场经理介绍 ,由于Dow lex IP/ 51的分子量分布宽 ,其流动性实际上与熔体流动速率为 70 g/1 0 m in的材料相当。新材料的密度和熔体流动速率已调至最佳值 ,兼具有良好的冲击强度和刚性 ,透明性较高冰箱级HDPE…     

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。