聚4-甲基-1-戊烯的研究进展及应用

综述了聚4-甲基-1-戊烯(PMP)的生产工艺和国内外4-甲基-1-戊烯聚合催化剂的研究进展,介绍了PMP的性能及应用,并对我国PMP合成技术存在的问题及发展方向提出了建议.     

聚4-甲基-1-戊烯的合成、结构与应用研究进展

从聚4-甲基-1-戊烯（PMP）的单体、催化剂、合成、分子链结构、晶体结构以及结晶行为进行阐述，综述了其在电子电器、节能降耗、包装材料以及医疗器械等领域的最新应用。PMP的合成包括丙烯二聚合成单体4-甲基-1-戊烯及其聚合。PMP合成技术有两种：一种是采用Ziegler-Natta催化剂的配位聚合，使用的主催化剂为Ti X(X表示卤素原子)，助催化剂为烷基铝；第二种是阳离子聚合。最后对PMP性能优化以及国产化提出展望。     

醋-丙共聚乳液胶粘剂的制备

采用预乳化半连续种子乳液聚合工艺对改性醋酸乙烯酯-丙烯酸丁酯共聚乳液胶粘剂的制备工艺进行了研究。实验中具体考察了聚合方式、单体配比、功能单体、乳化剂、引发剂、聚合温度、保护胶体等因素对乳液胶粘剂制备及性能的影响,确定了最佳工艺条件,并对所合成乳液胶粘剂的性能进行了测试与表征。当醋酸乙烯酯和丙烯酸丁酯的比例为1∶1时,共聚乳液具有最佳的粘接性能。功能性单体丙烯酸的加入可显著提高乳液的内聚力。聚合反应的最佳工艺条件是乳化剂的用量3%~5%,引发剂用量1%~3%,温度80℃。该工艺得到的改性醋-丙共聚乳液粒径分布均匀,机械稳定性好,并具有良好的纸塑粘接性能。     

2-(2-苄氧羰基氨基噻唑-4-基)-5-(3-甲基-2-丁烯氧羰基)-2-戊烯酸合成

对头孢布烯的关键中间体2-(2-苄氧羰基氨基噻唑-4-基)-5-(3-甲基-2-丁烯氧羰基)-2-戊烯酸(1)的制备工艺进行了研究。选用2-(2-苄氧羰基氨基噻唑-4-基)-2-戊烯二酸(2)与1-溴-3-甲基-2-丁烯进行选择酯化反应制得目标化合物1,反应总收率82.5%,该工艺操作简单,生产成本较低。     

4-甲基-1-戊烯的合成技术

4-甲基-1-戊烯(4MP1)作为共聚单体,可生产出性能优良的线型低密度聚乙烯LLDPE树脂。本文叙述了国外几种合成4MP1的技术路线,选择优化适合我国的生产方法,即丙烯在碱金属催化剂的作用下二聚生成4MP1,反应温度120-170℃,反应压力45.4-181.4MPa,反应过程的4MP1选择性大于80%,4MP1/4MP2大于20。     

丙烯二聚制4-甲基戊烯-1

以丙烯为原料,采用碱金属系催化剂在固定床中进行丙烯二聚连续反应,制备4-甲基戊烯-1。分别考察了载体组成、金属钠钾比以及负载量,合成的工艺条件对反应的影响。经800小时的连续运转试验表明,该催化剂具有良好的稳定性。     

苯乙烯、α-甲基苯乙烯改性C5石油树脂的研究

以苯乙烯、α-甲基苯乙烯为改性剂,采用阳离子聚合工艺合成了C5石油树脂,对聚合体系、改性剂等因素进行了分析.结果表明,无水AlCl3是引发C5-苯乙烯共聚体系的理想催化剂;苯乙烯与其余可聚单体的质量比在0.4-0.8,或α-甲基苯乙烯与其余可聚单体的质量比在1.0左右时,所得改性C5石油树脂具有良好的色相、软化点以及优...     

2-甲基-2-戊烯酸的合成与应用研究

以丙醛为起始原料,经羟醛缩合反应和空气氧化反应合成了2-甲基-2-戊烯酸,研究了2-甲基-2-戊烯酸在香精方面的应用。用该工艺合成的产品纯度高,香气好,具有较高的工业应用价值。     

二甲基叔丁基-(4-甲基-4-烯戊氧基)硅烷的合成及表征

首先以四氢呋喃为溶剂对3-氯-2-甲基丙烯进行格氏反应,制备出的格氏试剂再进一步与环氧乙烷反应其产物为4-甲基-4-戊烯醇,而后用叔丁基二甲基氯硅烷对上述产物4-甲基-4-戊烯醇上的羟基进行保护,制备出标题化合物。随后分别对4-甲基-4-戊烯醇以及标题化合物进行红外及核磁共振检测,所得到的检测谱图证实产物与目标分子的结构相吻合,并讨论了格氏试剂溶剂的选取对反应的影响。     

二甲基叔T基-(4-甲基-4-烯戊氧基)硅烷的合成及表征

首先以四氢呋喃为溶剂对3-氯-2-甲基丙烯进行格氏反应,制备出的格氏试剂再进一步与环氧乙烷反应其产物为4-甲基-4-戊烯醇,而后用叔丁基二甲基氯硅烷对上述产物4-甲基-4-戊烯醇上的羟基进行保护.制备出标题化合物.随后分别对4-甲基-4-戊烯醇以及标题化合物进行红外及核磁共振检测,所得到的检测谱图证实产物与目标分子的结构相吻合,并讨论了格氏试剂溶剂的选取对反应的影响.     

The effect of the ethylene pressure on its reaction with 1-hexene, 1-octene and 4-methyl-1-pentene

Summary Copolymers of ethylene and 1-hexexe, 1-octene and 4-methyl-1-pentene were obtained using Et[In]₂ZrCl₂/MAO catalyst at various pressures. The increase of 1-hexene and 1-octene concentration in the feed increases catalyst activity(g/nZr.h.bar) and productivity(g/nZr.h). For 4-methyl-1-pentene the activity is independent on comonomer concentration. Increasing the ethylene pressure the productivity of the copolymerization increases and the activity shows a weak decay. Characterization of the copolymer shows that at higher pressure the cristallinity of the copolymers is higher due to lower comonomer incorporation. There is a good linear correlation of cristallinity with comonomer concentration in the feed for 1-hexene and 1-octene at a fixed pressure, but not for 4-methyl-1-pentene.     

Preparation of syndiotactic polyolefins by using metallocene catalysts

Summary Polyolefins having syndiotactic structure were obtained by using 1-methyl-1-ethylidene-(cyclopentadienyl-1′-fluorenyl) zirconium dichloride and methylaluminoxane as a catalyst. 1-Butene and 4-methyl-1-pentene gave crystalline polymers having syndiotactic structure, while 1-pentene, 1-hexene and 1-octene gave noncrystalline polymers having syndiotactic structure. The identification of syndiotactic and isotactic polyolefins was made by ¹³C-NMR, X-ray diffraction, and differential scanning calorimetry.     

分子质量调节剂对丙烯酸酯乳液压敏胶性能的影响

采用预乳化半连续聚合法,合成了丙烯酸酯乳液压敏胶。探讨了叔十二烷基硫醇、2,4-二苯基-4-甲基-1-戊烯、乙二醇以及异丙醇等分子质量调节剂对压敏胶聚合稳定性、黏度、初粘性、持粘性和180o剥离强度的影响。结果表明,叔十二烷基硫醇和异丙醇对压敏胶的性能影响较大,2,4-二苯基-4-甲基-1-戊烯和乙二醇的影响较小;随分子质量调节剂用量增大,压敏胶的初粘性增大,持粘性和180o剥离强度先增大后降低,黏度先降低后又增大;加入2,4-二苯基-4-甲基-1-戊烯和异丙醇的乳液压敏胶聚合稳定性随分子质量调节剂用量增大而变差,加入叔十二硫醇的乳液压敏胶的聚合稳定性则随用量增大先变差后又增强,而乙二醇则与之相反。     

Process for production of pure 4-methyl-1-pentene

A process for the manufacture of pure 4-methyl-1-pentene by catalytic dimerization of propylene has been developed in three stages. The first stage involves preparation of a new process catalyst, which contains metallic sodium and potassium deposited on a Bulgarian natural zeolite, the support having been passivated previously by potassium carbonate. The experimental results demonstrate the advantages of the resulting catalyst over exisisting technology, namely 36% conversion and 92% selectivity relevant to liquid isomers. The second development stage concerns the technological regime of chemical reaction for production of 4-methyl-1-pentene. In the third stage, the regime conditions and equipment ensuring desired quality of the product and utilization of the unreacted propylene returned to the reactor are determined. Based on the studies of all stages, a flowsheet is proposed for synthesis and separation of the reaction mixture of isomeric hexenes to give pure 4-methyl-1-pentene.     

Polymerization of 4-methyl-1-pentene catalyzed by α-diimine nickel catalysts: Living/controlled behavior, branch structure, and mechanism

Branched α-olefin, 4-methyl-1-pentene (4 MP), was polymerized with classical α-diimine nickel complexes in the presence of MAO. Influences of structure of α-diimine nickel catalysts and polymerization parameters including temperature and [Al]/[Ni] mole ratio were evaluated. At 0 °C, 4-methyl-1-pentene can be polymerized in a living/controlled manner. The obtained poly(4-methyl-1-pentene)s are amorphous elastomers with low glass transition temperature (T_g). Nuclear magnetic resonance (NMR) and distortionless enhancement by polarization transfer (DEPT) analyses show that various types of branches and microstructural units are present in the polymers. On the basis of assignment of microstructures, mechanistic models that involves the 1,2- and 2,1-insertion, and chain walking were constructed. The influences of temperature and [Al]/[Ni] mole ratio on branching degree, branch type, and insertion pathways were also discussed in detail.     

Polymerization of olefins with bulky substituents. 1. Homo- and copolymerization of 3-(1-adamantyl)propene

The use of bulky substituents like adamantane has been shown in the past to influence the glass transition temperatures of polymers significantly. In this paper the synthesis and homopolymerization of the monomer 3-(1-adamantyl) propene is described, as well as the copolymerization of this monomer with ethene, propene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene. The resultant copolymers proved to be largely insoluble in organic solvents. It was also demonstrated that the presence of the bulky methyladamantyl side group influenced the glass transition temperatures of the copolymers in comparison with the corresponding homopolymers.     

Copolymerization of Propylene with 1-Hexene and 4-Methyl-1-Pentene in Liquid Propylene Medium. Synthesis and Characterization of Random Metallocene Copolymers with Isotactic Propylene Sequences

Summary Propylene copolymerization with 1-hexene and 4-methyl-1-pentene in liquid propylene medium in presence of MAO-activated C₂-symmetry ansa-zirconocene rac-Me₂Si(4-Ph-2-MeInd)₂ZrCl₂ was studied. Random copolymers of propylene with 1-hexene and 4-methyl-1-pentene content up to 7 mol % were obtained at 60 °C. General kinetic characteristics of propylene/higher α-olefin copolymerization were evaluated. The distinct feature of propylene copolymerization with 1-hexene and 4-methyl-1-pentene in liquid propylene medium – the proximity of comonomer relative reactivity ratios (r₁∼r₂∼1) that indicates azeotropic nature of copolymerization processes in studied conditions. Synthesized copolymers were characterized with the use of IR, ¹³C NMR, GPC, WAXD, DSC techniques, and uniaxial tensile testing.     

Catalytic Asymmetric Epoxidation of Unfunctionalized Olefins by Supported Cu(II)-Amino Acid Complexes

Polymer-supported Cu(II) complexes with L-phenyl alanine and L-valine were used as chiral catalysts for asymmetric epoxidation of nonfunctionalized straight-chain terminal olefins viz. 1-octene, 1-hexene, 2-methyl-1-pentene and 4-methyl-1-pentene using m-chloroperbenzoic acid (m-CPBA) as oxidant giving high conversions and selectivity. Enantiomeric yields, though moderate, are comparable with the best-reported ees using homogeneous catalysts. All catalysts displayed good recycling efficiency. Variations in percent ee have been discussed on the basis of the structural geometry of the supported catalysts and the trajectory of the olefin approach to the active oxo-intermediate.     

The cavitation development of poly(4-methyl-1-pentene) casting films studied by in situ small angle X-ray scattering

In this paper, the on-line small angle X-ray scattering/wide-angle X-ray scattering (SAXS/WAXS) characterization method was adopted to study the morphology evolution of poly(4-methyl-1-pentene) casting films during stretching. In this process, the lamellae structure was destroyed. And “bridge structure” was generated in the amorphous region. The scattering pattern changed obviously before and after cavities orientation. Stretching temperature and stretching speed mattered for the size of micropores. Low temperature helped generate more and larger voids. The faster stretching speed can improve the generation of cavities, enlarged cavitation number and helped its reorientation. These results provide the basic knowledge of how to produce poly(4-methyl-1-pentene) microporous membranes with high electrochemical performance.     

A new preparative method for cyclohexenyl alkenyl ketones

New cyclohexenyl alkenyl ketones are prepared by the reaction of various methyl cyclohexenyl carboxylates and vinylmagnesium chloride; for example, 1-(4′-methyl-3′-cyclohexene-1′-yl)-1-oxo-4-pentene is obtained from methyl 4-methyl-3-cyclohexene-1-carboxylate and vinylmagnesium chloride.