聚醚硅油表面迁移行为对聚苯乙烯表面极性的影响

利用变角衰减全反射傅立叶变换红外光谱(ATR-FTIR)法和接触角,分析了聚醚硅油在聚苯乙烯共混物薄膜表面的选择性富集行为及对其表面结构和表面极性的影响,认为接触介质的表面性质是影响共混物中各组分产生选择性迁移扩散的重要影响因素.强极性介质的诱导作用可以在共混物表面层中产生剧烈变化的浓度梯度,而弱极性介质所产生的表面浓度梯度比较缓和.     

聚乙烯尼龙共混物的PGC-MS和FT-IR联用鉴别

采用裂解气相色谱-质谱法和红外光谱法研究聚乙烯和尼龙共混物的组成;据此建立鉴别聚乙烯共混物组分的方法;红外光谱法可以准确鉴别出尼龙组分,裂解气相色谱-质谱法可以准确鉴别出聚乙烯组分以及尼龙的具体结构;二种方法结合使用,可以准确鉴别聚乙烯和尼龙共混物的组分。     

添加型聚丙烯大分子表面改性剂PP-g-PEG的制备及其应用

以马来酸酐为桥联剂,通过其与单端羟基聚乙二醇的反应,合成了大分子表面改性剂聚丙烯-聚乙二醇接枝共聚物,探索了反应条件对接枝反应的影响,用IR、NMR、TGA、DSC对接枝物的结构及性能进行研究,并通过共混研究了接枝物对聚丙烯的表面改性效果.结果表明,提高马来酸酐接枝聚丙烯或聚乙二醇的分子量,会阻碍接枝反应的进行,接枝率明显下降;接枝聚乙二醇降低了接枝物的结晶能力;聚丙烯-聚乙二醇接枝共聚物的热稳定性随着聚乙二醇的含量增加及侧链聚乙二醇长度的增加略有下降;聚丙烯-聚乙二醇接枝共聚物组分在共混物中具有明显的向外择优迁移特性,可以作为聚丙烯的添加型表面改性剂使用.     

含有机硅多嵌段及其接枝共聚物的表面组成

利用ＸＰＳ对聚二甲基硅氧烷与聚砜或／和聚对羟基苯乙烯组成的二元和三元多嵌段和接枝共聚物及其共混物进行了研究。结果表明溶液成果的聚合物样品的表面都存在有机硅富集，共混物的表面富集程度等于接枝共聚物，更高于多嵌段共聚物，讨论了有机硅含量和键接结构对有机硅表面富集的影响。     

淀粉／聚乙烯共混物的降解

淀粉和聚乙烯二者极性差别很大，如何提高淀粉／聚乙烯共混物降解塑料中两相的相容性是此项研究的技术关键．采用添加增容剂［１］，或进行淀粉疏水改性［２］，或对聚乙烯进行亲水改性［３］的办法均取得了一定的进展．本文在提高相容性研究的基础上，又添加油酸和有机铁...     

玻璃基板作用下高分子共混物薄膜相形态发展过程

研究了玻璃基板作用下极性高聚物为低组分的共混物薄膜在退火条件下相形态的发展过程 .选用聚苯乙烯 (PS) 聚甲基丙烯酸甲酯 (PMMA)与聚苯乙烯 (PS) 聚ε 己内酯 (PCL)两个体系 ,在玻璃基板上Spin Coating成膜后退火 .由于共混物薄膜中极性相对较大的高聚物组分 (PMMA和PCL)相对于极性较小的PS组分对玻璃基板具有更好的润湿性 ,所以在上述的两个共混薄膜体系中其相形态分别显示PMMA和PCL在低组分比例下最终发展成为连续相 .利用扫描电镜以及元素分析很好地验证了以上的结论 ,并且对其机理进行了解释 .此外 ,改变PS的分子量与PCL共混 ,研究了组分粘度对薄膜相形态发展的影响 .结果表明 ,PS组分粘度越大 ,共混物薄膜相结构发展速度越慢     

正交投影耦合光谱平滑性红外光谱法用于聚乙烯/聚丙烯共混物的定量分析

运用正交投影技术，结合目视背景光谱平滑性，对二元共混物中各组分进行红外光谱定量分析。将该法用于聚乙烯／聚丙烯共混物的实际样品测定，能满足生产控制的要求。     

（PSF—PDMS—PHS）n／PSF共混物的相容性及表面组成

利用ＤＳＣ、ＤＭＡ、ＴＥＭ和ＸＰＳ对［ＰＳＦ－ＰＤＭＳ－ＰＨＳ］ｎ／ＰＳＦ共混物的相容性及表面组成进行了研究．结果表明，ＰＤＭＳ在共混物表面的富集与ＰＳＦ均聚物和［ＰＳＦ－ＰＤＭＳ－ＰＨＳ］ｎ中硬段的相容性有关；ＰＤＭＳ在相容的共混物体系表面的富集与对应的多嵌段共聚物组成基本相近；不相容共混物体系表面ＰＤＭＳ的富集程度相对较高，当共混物本体中有机硅含量从１％增至５％，表面层ＰＤＭＳ的含量迅速增加，可达到嵌段共聚物中ＰＤＭＳ的含量．     

聚乙烯/聚己内酯-聚乙二醇共聚物共混物组分相容性及其光水双降解的研究

用动态力学振簧仪、DSC、FT IR、光辐照、浸水降解法研究了马来酸酐化线型低密度聚乙烯 (MPE) /聚己内酯 聚乙二醇共聚物 (PCE)共混物的组分相容性、晶区的熔化和结晶行为以及降解特性 .结果表明 ,马来酸酐化是发生在LLDPE短支链的甲基末端上并通过马来酸酐与PCE的羟基形成氢键相互作用 ,使两组分存在部分相容性 ,PCE的主转变与MPE支链的 β转变发生内移现象 .在共混物中加入乙烯 丙烯酸共聚物(EAA)可以起增容作用 ,同时使MPE和PCE组分的熔点和熔化热进一步下降 .对不同含量PCE的MPE/PCE/EAA共混物的降解特性的研究表明 ,PCE的加入使体系发生光、水降解 ,且随PCE含量的增加降解速度加快 .光 水联合作用的降解速度比单一光或水降解更快 .     

PEO／PVP共混体系结晶行为

本文用WAXD、PLM、DSC方法研究了聚氧化乙烯(PEO)/聚乙烯基吡咯烷酮(PVP)共混体系的结晶行为,探索了两组分聚合物间相互作用及体系结晶度与非晶组分含量的关系。DSC研究表明PEO/PVP共混体系具有两个玻璃化转变温度,分别是纯组分的T_g,无相容性。应用Avrami和LH方程对其动力学参数进行了研究。偏光显微镜观察了共混物结构形态。     

Formation of nanoporous poly(aryl amide ether) (PAAE) films by selective removal of poly(ethylene glycol) (PEG) from PEG/PAAE composite films

Poly(aryl amide ether) (PAAE) thin films with nanometer-sized pores have been prepared in two steps: (1) solution casting of partially miscible poly(ethylene glycol) (PEG)/PAAE blends from one of their common solvents, dimethyl sulfoxide (DMSO), results in formation of PEG/PAAE nanocomposite films; (2) selective removal of PEG component by water washing yields nanosized, porous PAAE films. The pores have been found to have a small size variation and cover the whole surface homogeneously. With an increase in PEG contents, the sizes of the pores increase but the size distributions do not have much changes. This has been ascribed to formation of small PEG domains in PEG/PAAE composite films, which is facilitated by the strong interactions, mostly hydrogen bonds, between PEG and PAAE macromolecular chains.     

Sodium Alginate and Poly(ethylene glycol) Blends: Thermal and Morphological Behaviors

Sodium alginate (SA) was blended with varying amounts of poly(ethylene glycol) (PEG) viz., 10, 20, 30, 40 and 50 wt % by using water as a solvent. The obtained SA/PEG blends have been characterized for thermal behavior by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and surface morphology by scanning electron microscopic (SEM) methods. DSC analysis indicates the increase in glass transition temperature (T_g) of the blends with an increase in PEG content in the blend, which is due to chain entanglement. TGA results reveal the enhancement of thermal stability of SA/PEG blends in terms of the onset of degradation and percentage of weight loss. SEM photomicrographs shows the two phase morphology. This result indicates the immiscible nature of the SA/PEG blends.     

Poly(ethylene glycol) self-assembled monolayer island growth

Here, we report a study of the morphology and growth dynamics of a self-assembled monolayer (SAM) of the amide containing poly(ethylene glycol) (PEG) thiol (CH3O(CH2CH2O)17NHCO(CH2)2SH) on atomically flat Au(111) surfaces. SAM growth from a 20 muM ethanolic solution reveals island growth through three distinct steps: island nucleation, island growth, and coalescence. The coalescence-step, filling voids in the SAM, is by far slowest. The fine structure study reveals dendritic island formation, an observation which can be explained by attractive intermolecular interactions and surface diffusion-limited aggregation. We have also observed a change in the island height, which peaks during the island growth phase. This height change can be associated with a molecular conformational transition.     

无规聚甲基丙烯酸甲酯在聚乙二醇齐聚物溶液中的自组织及凝胶行为

高度立构规整的聚甲基丙烯酸甲酯在许多有机溶剂中都有形成热可逆凝胶的倾向[1] .高间规度的聚甲基丙烯酸甲酯 ( s PMMA)在溶液及凝胶中的自组织行为可以通过核磁共振、光散射、小角中子散射及红外光谱来研究 [2～ 5] .在甲苯、邻二甲苯和邻二氯苯等溶剂中 ,s PMMA链中的大部分单元都处于有序状态 ;而在苯和氯仿等溶剂中 ,没有这种有序结构形成 ,分子链处于无规线团状态 [5,6] .一般认为 ,这种有序结构的形成与分子链中一定长度间规序列结构单元的存在有关 [7] .对于无规聚甲基丙烯酸甲酯 ( a PMMA) ,由于其较低的间规度 ( <66% ) ,在…     

Characterization of amphiphilic hydrocarbon modified Poly(ethylene glycol) synthesized through ring-opening reaction of 2-(1-octadecenyl)succinic anhydride

Poly(ethylene glycol) (PEG) triblock and diblock amphiphilic block copolymers were synthesized from poly(ethylene glycol) and poly(ethylene glycol) monomethyl ether, respectively. The hydroxyl groups of PEG readily react with 2-(1-octadecenyl) succinic anhydride (OSA) at 140 °C through ring-opening reaction of the succinic anhydride. Both the PEG-OSA diblock and triblock copolymers are produced without use of any solvent or catalyst. The molecular structure of the copolymers was characterized by ¹H NMR and FTIR spectroscopy, and the thermal properties by DSC. The behavior of the copolymers in selective and nonselective solvents was studied by ¹H NMR spectroscopy in deuterium oxide and d-chloroform. The aggregation of the polymers in water was studied with a particle size analyzer and a transmission electron microscope (TEM) in bright field mode. The results show that the hydrophobic C₁₈ chain with intramolecular succinic anhydride linker can be attached to the hydrophilic PEG chain, an ester bond forming between the blocks. The copolymers exhibit flexible, liquid-like hydrophobic blocks even in water, which is a nonsolvent for OSA. PEG-OSA block copolymers self-organize in water, forming micellar polymer aggregates in nanoscale.     

Side‐chain crystallization behavior of graft copolymers consisting of an amorphous main chain and crystalline side chains. II. Poly(n‐hexyl methacrylate)‐graft‐poly(ethylene glycol)

The phase behavior and crystallization of graft copolymers consisting of poly(n‐hexyl methacrylate) (PHMA) as an amorphous main chain and poly(ethylene glycol) (PEG) as crystallizable side chains (HMAx with 15 ≤ x ≤ 73, where x represents the weight percentage of PEG) were investigated. Small‐angle X‐ray scattering profiles measured above the melting temperature of PEG suggested that a microdomain structure with segregated PHMA and PEG domains was formed in HMA40 and HMA46. This phase behavior was qualitatively described by a calculated phase diagram based on the mean‐field theory. Because of the segregation of PEG into microdomains, the crystallization temperature of the PEG side chains in HMAx was higher than that in poly(methyl acrylate)‐graft‐poly(ethylene glycol) having a similar value of x, which was considered to be in a disordered state above the melting temperature. In HMAx with x ≤ 40, PEG crystallization was strongly restricted, probably because the PEG microdomains were isolated in the PHMA matrix. As a result, the growth of PEG spherulite was not observed because the PEG crystallization occurred after vitrification of the PHMA segregated domains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 129–137, 2007     

The influence of UV light on collagen/poly(ethylene glycol) blends

The photodegradation behaviour of the collagen and poly(ethylene glycol) PEG blends has been studied by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and viscometry. Surface properties before and after UV irradiation were observed using optical microscope.Collagen and PEG were immiscible and the films obtained from the mixture were fragile with poor mechanical properties. The photochemical stability of the collagen and PEG blend was different from that of the single components. In general collagen/PEG blends are less stable under UV irradiation than pure collagen. The influence of PEG on the photochemical stability of collagen depends on its concentration in the blend. Microscope photographs showed that the surface characteristics of collagen and collagen/PEG blends in film form are not drastically altered after UV irradiation.     

Synthesis of polyvinyltrimethylsilane-graft-poly(ethylene glycol) copolymers and properties of gas-separating membranes formed on their basis

A method is developed for the synthesis of the graft copolymer polyvinyltrimethylsilane-graft-poly(ethylene glycol) via the interaction of a brominated polymer with the methyl ether of a low-molecular-mass poly(ethylene glycol). Graft copolymer samples containing up to 79 wt % poly(ethylene glycol) are synthesized through this method. The properties of the graft copolymers and blends formed on their basis with a specially synthesized low-molecular-mass PEG derivative with a terminal trimethylsilyl group are investigated. Physical blends are prepared in order to increase the content of ethylene oxide groups while the film-forming properties of the composite materials are preserved. As shown by structural studies, the graft copolymers are amorphous single-phase systems, while the related blends are two-phase disperse systems, in which one phase is enriched in polytrimethylvinylsilane and the other is enriched in PEG. Studies of the gas-transport behavior of the samples reveal that the introduction of PEG, in contrast to the nonselective initial polymer, results in the formation of PVTMS-based materials that are selective for CO₂ in mixtures with H₂.     

Poly(ethylene glycol)-based shape-memory polymers

Poly(ethylene glycol) (PEG) blends photo-curable and thermal activated shape-memory polymers (SMPs), with different activation temperature (T_switch), have been synthesized and characterized. PEG blends with different molecular weights were chain-end functionalized with isocyanate ethyl methacrylate and photo-cured with UV lamp. Degree of cross-linking of the blend network, determined by gel content measurement, resulted as higher than 95%. The thermal and thermomechanical properties of these SMPs PEG blends were characterized by differential scanning calorimetry and dynamic mechanical analysis. The shape-memory properties of the networks were quantified using thermomechanical three-point bending experiments and showed strain fixity rates higher than 99% and a minimum strain recovery ratio of 82%.     

嵌段共聚酯的合成研究

采用直接酯化法合成了一系列含间苯二甲酸的PEIT－PEG嵌段共聚酯,研究了聚合时间,聚合效率及聚酯的特性粘度与产物中间苯二甲酸含量及共聚酯分子量的关系,得出适于纺丝工艺及工业化生产的共聚酯分子量和间苯二甲酸的含量。