乙烯-乙酸乙烯酯共聚物中乙酸乙烯酯的红外光谱法测定

利用ATR技术测量样品的红外光谱,采用偏最小二乘法对所测光谱进行分析,建立了一种快速分析方法;对乙烯-乙酸乙烯酯共聚物中乙酸乙烯酯进行测定。结果表明：标准曲线线性关系良好,相关系数为0．99985,方法简单快速,结果可靠。     

氯化乙丙共聚物的红外光谱分析

用钛系高效催化剂进行乙烯—丙烯共聚合,得到乙烯、丙烯摩尔比分别为1∶1和2∶1的两个乙丙共聚物,共聚物大分子链主要由聚乙烯和聚丙烯链段构成,聚丙烯链段的等规性很低。共聚物的氯化产物的红外光谱具有氯化聚乙烯和氯化聚丙烯的特征吸收。通过分析,确定了含各种C-Cl键链节的化学结构类型,并讨论了避免产生氯化共聚产物中含甲苯不溶物的问题.     

傅立叶变换红外光谱测定PMMA-S共聚物的共聚组分

研究了用傅立叶变换红外光谱定量分析PMMA -S共聚物共聚组分的方法。结果表明 ,PMMA -PS共混物经红外光谱中 13 85cm- 1 和 699cm- 1 处吸光度之比对共混比的工作曲线有较好的线性关系 ,PMMA -S共聚物的共聚组成可由此工作曲线获得     

中红外光谱法快速测定汽油中的甲苯含量

利用日本岛津公司生产的IRAffinity-1型傅里叶变换红外光谱仪对汽油中甲苯含量进行测定,并根据朗伯-比尔定律,对甲苯进行定量分析。结果表明,利用中红外光谱法可以快速准确测定汽油中甲苯的含量,相对于气相色谱法而言具有快速、简便的特点。     

傅立叶变换红外光谱法测定食品中反式脂肪酸

建立了一种食品中反式脂肪酸含量的测定方法,以酸水解法提取食品中脂肪酸,用傅立叶变换红外光谱仪对反式脂肪酸含量进行了快速测定,回收率达到89.26%~106.51%,相对标准偏差2.29%,结果重复性好,准确可靠。     

傅立叶变换红外光谱法在纤维分析中的应用

本文综述了傅立叶变换红外光谱法在纤维分析中的应用与进展。内容涉及衰减全反射和漫反射傅立叶变换红外光谱法,傅立叶变换红外光声光谱法、显微傅立叶变换红外光谱法,傅立叶变换红外光谱仪与各种仪器的联用,以及计算机技术的应用与发展。     

苯乙烯在异氰酸酯官能化二元乙丙橡胶中的作用

在苯乙烯（St）存在下,以2,5-二甲基-2,5-双（叔丁基过氧基）己烷（DHBP）为引发剂,3-异丙烯基-α,α-二甲基苄基异氰酸酯（TMI）为接枝单体,于哈克转矩密炼机中对二元乙丙橡胶（EPM）进行了自由基接枝官能化,产物用傅立叶红外光谱仪进行表征,并用化学滴定法对接枝率进行测定。实验结果表明,TMI成功地接枝到EPM上;适量St作为共单体加入体系中起到抑制EPM中PP链段的降解和提高TMI的接枝率两方面作用。     

13C-NMR波谱法研究乙丙共聚物的微观序列结构

利用索氏抽提分离、升温淋洗分级对乙丙共聚物进行分级,对分级后的级分做核磁共振碳谱测试.研究了乙丙共聚物的链段存在形式,讨论了不同级分试样结构上的差别,建立了适合工业生产和科研开发过程中评价产品序列结构的方法.     

SIS中结合苯乙烯质量分数的测定

用红外光谱的标准加入法测定了异戊二烯－苯乙烯嵌段共聚物中结合苯乙烯的质量分数,３次测定的平均结果为２１．５％,相对标准偏差为３．３％。     

高相对分子质量PP-R高强高韧机理的研究

在工业化聚丙烯(PP)装置生产出高相对分子质量的乙丙无规共聚PP(HWPPR1),用差示扫描量热仪、X射线衍射仪和偏光显微镜研究了HWPPR1和常规相对分子质量PP-R的非等温结晶行为、晶体结构和形态,并测试了力学性能。结果表明,HWPPR1表现出很高的刚性和韧性,其常温缺口冲击强度和拉伸强度分别比常规相对分子质量抗冲共聚物高约21J/m和5MPa。     

马来酸酐熔融接枝二元乙丙橡胶的研究

在转矩流变仪中,以过氧化二异丙苯(DCP)为引发剂,采用多单体熔融接枝技术,研究了二元乙丙橡胶(EPM)熔融接枝马来酸酐(MAH),考察了MAH含量、DCP用量、反应温度、反应时间、转子转速以及第二单体苯乙烯(St)的用量对接枝反应的影响,并用红外光谱(FTIR)对接枝产物进行了表征.研究结果表明:对于EPM-g-MAH体系,MAH和DCP最佳用量分别为3.0 phr和0.22 phr,最佳反应温度为170℃,反应时间8 min,转子转速60 r/min,此时接枝率最高达到0.46％;加入第二单体St后,当n(St) /n(MAH)为1/1时,EPM-g-(MAH-co-St)的接枝率为0.64％,接枝率明显提高.     

Primary nucleation behaviour in isotactic polypropylene/ethylene-propylene random copolymer blends

Primary nucleation of spherulites in blends of isotactic polypropylene (iPP) with ethylene-propylene random copolymer (EPM) has been investigated using optical microscopy. The number of spherulites generally increases with increasing EPM content. It is shown that this increase is caused by migration of heterogeneous nuclei across interface boundaries from EPM to iPP during melt-mixing. The migration was observed in the blends with the nucleating agent initially added to EPM before blending with iPP. It is suggested that the interfacial free energy difference between nuclei and the molten components of the blend is responsible for the migration of nuclei. It is also shown that self-seeded nucleation becomes damped in the blends due to partial solubility of the components and that the degradation of the blends during melt-annealing depresses the primary nucleation.     

C nuclear magnetic resonance spectral analysis of stereosequences in ethylene-propylene copolymer

A number of split peaks dependent on both comonomer sequences and stereosequences were observed in the ¹³C nuclear magnetic resonance (n.m.r.) spectrum of ethylene-propylene (E-P) copolymer. The ¹³C chemical shifts of methylene carbon in stereoisomers of the respective hexad comonomer sequences were predicted by a chemical-shift calculation using the gamma effect on ¹³C chemical shifts and Mark's rotational isomeric state model for E-P copolymer. Assignments of the split peaks that arise from different hexad stereosequences were given by comparison between the observed and calculated chemical shifts. Reference was made to the hexad assignments of comonomer-sequence-dependent peak splittings determined in our previous calculation of ¹³C n.m.r. chemical shifts of stereoregular E-P copolymers. The tacticities were estimated for successive (not separated by ethylene units) propylene units in the hexad sequences.     

用13C-NMR表征高乙烯含量乙烯-丙烯无规共聚物的结构与性能

采用淤浆聚合法,使用3种聚丙烯催化剂制备了高乙烯含量乙烯-丙烯无规共聚物,并采用核磁共振碳谱对共聚物结构和性能进行了表征。结果表明:在相同聚合条件下,使用二醇酯化合物作为内给电子体的ND催化剂同已商业化的两种Ziegler-Natta催化剂CAT1和CAT2聚合得到的乙烯-丙烯无规共聚物中的乙烯摩尔分数接近,为75%~78%;使用ND催化剂聚合得到的乙烯-丙烯无规共聚物链段中乙烯-丙烯单元序列分布更均匀;使用ND催化剂聚合得到的乙烯-丙烯无规共聚物中橡胶相相对含量高于采用CAT1和CAT2催化剂。     

Preparation and characterization of amphiphilic block copolymer of polyacrylonitrile‐block‐poly(ethylene oxide)

The synthesis of polyacrylonitrile‐block‐poly(ethylene oxide) (PAN‐b‐PEO) diblock copolymers is conducted by sequential initiation and Ce(IV) redox polymerization using amino‐alcohol as the parent compound. In the first step, amino‐alcohol potassium with a protected amine group initiates the polymerization of ethylene oxide (EO) to yield poly(ethylene oxide) (PEO) with an amine end group (PEO‐NH₂), which is used to synthesize a PAN‐b‐PEO diblock copolymer with Ce(IV) that takes place in the redox initiation system. A PAN‐poly(ethylene glycol)‐PAN (PAN‐PEG‐PAN) triblock copolymer is prepared by the same redox system consisting of ceric ions and PEG in an aqueous medium. The structure of the copolymer is characterized in detail by GPC, IR, ¹H‐NMR, DSC, and X‐ray diffraction. The propagation of the PAN chain is dependent on the molecular weight and concentration of the PEO prepolymer. The crystallization of the PAN and PEO block is discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1753–1759, 2003     

Modeling of molecular weight and copolymer composition distributions for ethylene-propylene solution copolymerization

A comprehensive computational fluid dynamics (CFD) model was developed to investigate spatial distributions of molecular weight distribution (MWD) and copolymer composition distribution (CCD) for ethylene-propylene (EPM) copolymers in a bubble column reactor. The CFD approach incorporated Euler–Euler two-fluid model, copolymerization kinetics, and copolymer microstructural distribution model together by user-defined functions for ethylene-propylene heterogeneous copolymerization process. MWD and CCD distributions were calculated by introducing Flory's distribution and Stockmayer's distribution, respectively. CFD model results were validated with literature data. The multiphase hydrodynamics, interphase mass transfer, spatial–temporal variations of MWD and CCD distributions were analyzed. Both distributions are wider at the inlet of reactor for the inefficient mixing, but narrower at the outlet due to fully developed flow and polymerization. This model is beneficial to the improvement of polymer products and process control in industrial EPM reactor.