乙烯四聚制1-辛烯催化剂研究进展

介绍了传统乙烯齐聚生产1-辛烯工艺,分析了乙烯四聚反应制1-辛烯机理,叙述了乙烯四聚制1-辛烯铬系催化体系中配体、助催化剂和促进剂的国内外最新进展。认为目前研究热点集中在PNP配体上N原子取代和助催化剂及促进剂的筛选等方面,国内急需解决聚乙烯共聚单体1-己烯和1-辛烯的工业化生产问题。     

乙烯四聚制1-辛烯的研究

研究了乙烯选择性四聚制1-辛烯的催化剂体系,利用氯化二苯基膦与胺反应生成二苯基膦胺配体,它与乙酰丙酮铬在助催化剂的存在下显示出较高的催化乙烯四聚的活性和较高的1-辛烯选择性;考察了不同溶剂、温度、压力、n(Al)/n(Cr)及第四组分对催化剂体系的影响,确定了适宜的条件,当n(Cr)/n(PNP)/n(Al)为1∶2∶300,反应温度为30℃,压力为3 MPa时,反应时间为30 min,进行乙烯四聚实验,催化剂活性达58.10 kg/(g·h),1-辛烯的选择性接近70%。     

1-辛烯对超高分子量聚乙烯抗冲击性能的影响

针对超高分子量聚乙烯(UHMWPE)抗冲击性能不足的问题,通过改变聚合工艺条件,引入共聚单体1-辛烯,研究1-辛烯对UHMWPE树脂性能的影响,考察了所得产物的热性能及力学性能.结果表明:聚合中加入少量的1-辛烯,有助于提升UHMWPE树脂的抗冲击性能,当体系内1-辛烯浓度为0.127 mol/L时,所得产物的综合力学...     

乙烯选择性四聚制1-辛烯催化剂及工艺技术研究进展

综述了近年来乙烯选择性四聚制1-辛烯技术的发展现状。介绍了乙烯选择性四聚制1-辛烯催化剂研究的最新进展及发展趋势;重点阐述了影响乙烯选择性四聚制1-辛烯催化体系中的两个重要组分,即助催化剂和配体;从技术和经济方面对比了现有技术制1-辛烯的可行性。     

钯的二亚胺催化剂催化1-辛烯乳液聚合

以钯的二亚胺为催化剂,在乳液体系中催化1-辛烯均聚合及1-辛烯与丙烯酸甲酯(MA)共聚合。通过光散射分析仪、差示扫描量热仪、凝胶渗透色谱仪、核磁共振谱仪测定了聚合物的粒径、熔点、相对分子质量,表征了其结构。结果表明:该催化剂在乳液体系中可以催化1-辛烯均聚合及1-辛烯与MA的共聚合;聚合物相对分子质量可达2.30×104以上,且相对分子质量分布(1.0～2.0)较窄,共聚物中MA与1-辛烯的摩尔比高达1.0∶4.5;均聚物的支化度(81.8个/1 000 C)和共聚物的支化度(112.8个/1 000 C)均较高;共聚物为半结晶型共聚物,其玻璃化转变温度为-57℃,熔点为83℃。     

辛烯-1共聚产品生产、技术发展状况

综述了溶液法生产辛烯-1共聚物的Nova Sclairtech工艺特点,介绍了当前辛烯-1共聚物种类、新产品研究开发以及催化剂的发展状况.     

AlCl3-丙三醇络合催化剂催化1-辛烯齐聚工艺

以1-辛烯为原料,A1C13/丙三醇络合物为催化剂,催化1-辛烯齐聚反应,合成α-烯烃。考察了络合催化剂的添加量、反应温度、反应时间、丙三醇与AlCl3的摩尔比对聚α-烯烃(PAO)收率的影响。结果表明,在AlCl3摩尔分数为4%,丙三醇与AlCl3的摩尔比为0.5,反应温度为40℃,反应时间为4 h的条件下,PAO收率达到85.6%,且具有较好的选择性。     

AlCl_3-丙三醇络合催化剂催化1-辛烯齐聚工艺

以1-辛烯为原料,A1C13/丙三醇络合物为催化剂,催化1-辛烯齐聚反应,合成α-烯烃。考察了络合催化剂的添加量、反应温度、反应时间、丙三醇与AlCl3的摩尔比对聚α-烯烃（PAO）收率的影响。结果表明,在AlCl3摩尔分数为4%,丙三醇与AlCl3的摩尔比为0.5,反应温度为40℃,反应时间为4 h的条件下,PAO收率达到85.6%,且具有较好的选择性。     

我国微生物法丙烯酰胺总产量已居世界第一

辛烯-1是重要的聚乙烯共聚单体。其抗撕强度和抗冲击强度是丁烯-1共聚聚乙烯的2倍、己烯-1共聚聚乙烯的1．5倍。辛烯-1用做共聚单体可明显改善聚乙烯的密度,提高其抗撕裂和拉伸强度等机械性能;用做增塑剂时,可以使聚乙烯制品的低温柔软性、加工性、室外耐候性更好,尤其适用于制造电缆电线、汽车配件或装饰件等。辛烯-1作为共聚单体的加入量一般为8％-10％,我国每年辛烯-1的潜在需求量已超过12万吨。目前国内没有专门生产辛烯-1的装置。国外公司只卖产品,不卖技术,辛烯-1进口价格十分昂贵,影响了我国合成树脂新牌号品种的开发和质量提高。     

聚二甲基硅氧烷改性乙烯-1-辛烯共聚物微孔发泡

针对乙烯-1-辛烯共聚物(POE)发泡过程中泡孔易破裂的问题,提出将马来酸酐(MAH)接枝到POE上、然后与多氨基硅油(PDMS-NH2)反应的方法,形成具有支化结构并部分交联的改性POE(POE-PDMS),并以超临界二氧化碳为发泡剂进行微孔发泡,系统考察了上述改性POE的发泡行为及发泡材料压缩性能,结果表明,PDM...     

新型抗冲击改性剂茂金属乙烯—1—辛烯共聚物的特性及应用

简述了乙烯－1－辛烯共聚物（POE）的性能特点，重点介绍了POE对PP、尼龙、PBT、PET、PC等塑料的增韧作用。     

淤浆法聚乙烯CX工艺及其催化剂研究进展

日本三井油化公司研发的淤浆法聚乙烯CX工艺控制技术先进,流程布局合理,牌号切换快捷,是应用广泛的聚乙烯生产工艺之一,主要用于生产高密度聚乙烯。介绍CX工艺流程,对日本三井油化公司开发的PZ和RZ系列催化剂、中国石化北京化工研究院研发的BCH和BCE系列催化剂、辽宁向阳科化集团开发的XY-H系列催化剂、中国石化石油化工科学研究院研发的NT-1催化剂以及中国石油自主研发的PSE-101催化剂等常用的CX工艺聚乙烯催化剂进行综述,对我国CX工艺聚乙烯催化剂的研究和应用提出建议。     

Effect of short chain branching on the blown film properties of linear low density polyethylene

Three linear low density polyethylene (LLDPE) resins of similar melt index and density were synthesized with different comonomers in the Unipol pilot-plant scale reactor. The molecular structure, blown film morphology, and film strength properties of the resins have been comprehensively characterized. The film dart drop impact strength of the LLDPEs increases in the order of ethylene/1-butene, ethylene/1-octene, and ethylene/1-hexene copolymers; whereas the Elmendorf tear strength of them increases in the order of ethylene/1-butene, ethylene/1-hexene, and ethylene/1-octene copolymers. The mechanical properties seem to be highly associated with the length and distribution of short chain branches and, consequently, the lamellar thickness distribution of the resins. © 1996 John Wiley & Sons, Inc.     

Effects of polymer structure on the onset of processing defects in linear low density polyethylenes

Linear low density polyethylenes are manufactured by copolymerizing ethylene with 1-alkenes, yielding a linear polyethylene backbone with short side chains. Due to the nature of the catalyst used in the polymerizaton, multimodal branching distributions are typically obtained. In this report, we have investigated the processability of four 1-octene linear low density polyethylenes as a function of the short chain branching distribution. Analytical techniques such as ¹³C nuclear resonance spectroscopy, size exclusion chromatography, differential scanning calorimetry, and temperature rising elution fractionation, in particular were used to elucidate the molecular structure. Processability measurements were made using various extrusion techniques and dynamic mechanical analyses.It was determined that in the absence of any variations in molecular weight, the polymers with the higher proportions of linear polyethylene showed inferior processability In terms of onset of surface imperfections at lower extrusion rates. Polymers with worse processability characteristics also exhibited higher zero shear viscosities.     

加快国内1-己烯生产促进聚乙烯的发展

介绍了国外生产1-己烯的主要技术路线及国内今后市场需求,采用1-己烯作为共聚单体的线型低密度聚乙烯树脂在性能上优于用1-丁烯作共聚单体所得的树脂,建议国内尽快解决1-己烯的建设和生产,以加快聚乙烯树脂的发展。     

Interfacial Interpretation of Autohesion of Ethylene/1-Octene Copolymers by Atomic Force Microscopy

The T-peel fractured surfaces of bonded films of ethylene/1-octene copolymers with different 1-octene contents were characterized using atomic force microscopy (AFM) and analyzed by fractal analysis. The AFM images showed strong dependence on the bonding temperature, peel rate, and the 1-octene content visually. This dependence has been demonstrated quantitatively by the fractal analyses which quantified an irregular surface by fractal dimensions and characteristic sizes. Two regimes showing fractal features were identified for each surface. In Regime I (higher magnifications) the welding and the following T-peel fracture procedures did little to change the fractal dimensions compared with the original surfaces before welding. But there were significant changes in Regime II (lower magnification) before welding and after T-peel fracture tests. The length scale that separated these two regimes is of the same order as that of polyethylene lamellar crystal structures. This suggests that the amorphous chains interdiffused across the interface while unmelted interfacial crystal structures remain essentially unaltered during the autohesion process. A “stitch-welding” autohesion mechanism was proposed to describe the bonding process in which only chains in the amorphous portions could interdiffuse. During the T-peel fracture tests, a crystal structure on the interface is either pulled over to the other side of the interface due to the interdiffused chains, remains unchanged, or is used as an anchor to pull a crystal structure from the other side of the interface. The characteristic sizes at which the fractal characteristics emerge were shown to be larger for the surfaces fractured at higher peel rates, which corresponds to higher fracture energy. This suggests that the appearance of fractal behavior at larger scales requires higher fracture energies. The characteristic sizes and fractal dimensions were also shown to depend on the molecular structure.     

Interfacial Interpretation of Autohesion of Ethylene/1-Octene Copolymers by Atomic Force Microscopy

The T-peel fractured surfaces of bonded films of ethylene/1-octene copolymers with different 1-octene contents were characterized using atomic force microscopy (AFM) and analyzed by fractal analysis. The AFM images showed strong dependence on the bonding temperature, peel rate, and the 1-octene content visually. This dependence has been demonstrated quantitatively by the fractal analyses which quantified an irregular surface by fractal dimensions and characteristic sizes. Two regimes showing fractal features were identified for each surface. In Regime I (higher magnifications) the welding and the following T-peel fracture procedures did little to change the fractal dimensions compared with the original surfaces before welding. But there were significant changes in Regime II (lower magnification) before welding and after T-peel fracture tests. The length scale that separated these two regimes is of the same order as that of polyethylene lamellar crystal structures. This suggests that the amorphous chains interdiffused across the interface while unmelted interfacial crystal structures remain essentially unaltered during the autohesion process. A “stitch-welding” autohesion mechanism was proposed to describe the bonding process in which only chains in the amorphous portions could interdiffuse. During the T-peel fracture tests, a crystal structure on the interface is either pulled over to the other side of the interface due to the interdiffused chains, remains unchanged, or is used as an anchor to pull a crystal structure from the other side of the interface. The characteristic sizes at which the fractal characteristics emerge were shown to be larger for the surfaces fractured at higher peel rates, which corresponds to higher fracture energy. This suggests that the appearance of fractal behavior at larger scales requires higher fracture energies. The characteristic sizes and fractal dimensions were also shown to depend on the molecular structure.     

Precision polyolefin structure: Modeling polyethylene containing alkyl branches

Step-growth acyclic diene metathesis (ADMET) polymerization chemistry followed by exhaustive hydrogenation offers a new modeling approach for the study of polyethylene structures. ADMET controls branch identity and frequency, both of which are predetermined during the monomer synthesis, allowing sequence control in the resultant polymer. This review describes the synthesis and thermal behavior of ADMET polymers that serve as models for copolymers of ethylene with α-olefins such as 1-propene, isobutylene 1-butene, and 1-octene.