ELASTIC BEHAVIOR OF COMB-LIKE POLYMER CHAINS

Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths Nb, arm lengths Na and arm densities m are carried out to study the elastic behavior of comb-like polymer chains. The radius of gyration, the shape factors and bond length in different cases during elastic process are calculated, and it is found that the comb-like polymer molecules with longer backbone or shorter arm are more close to linear chains. But the arm density rn affects the chain conformation non-monotonously. Some thermodynamic properties are also studied. Average Helmholtz free energy and elastic force fall increase with elongation ratio 2 for all chains.

Ultrathin polyamide nanofiltration membrane prepared by triazine-based porous organic polymer as interlayer for dye removal

Separation membrane with high flux is generally encouraged in industrial application,because of the tremendous needs for decreasing membrane areas,usage costs and space requirements.The most effective and direct method for obtaining the high flux is to decrease membrane thickness.Polyamide(PA)nanofiltration membrane is conventionally prepared by the direct interfacial polymerization(IP)on substrate surface,and results in a thick PA layer.In this work,we proposed a strategy that constructing triazine-based porous organic polymer(TRZ-POP)as the interlayer to prepare the ultrathin PA nanofiltration membranes.TRZ-POP is firstly deposited on the polyethersulfone substrate,and then the formed TRZ-POP provides more adhesion sites towards PA based on its high specific surface areas.The chemical bonding between terminal amine group of TRZ-POP and the amide group of PA further improves the binding force,and strengthens the stability of PA layer.More importantly,the high porosity of TRZPOP layer causes the higher polymerization of initial PA owning to the stored sufficient amino monomer;and H-bonding interaction between amine groups of TRZ-POP and piperazine(PIP)can astrict the release of PIP.Thus,IP process is controlled,and the thinnest thickness of prepared PA layer is only<15 nm.As expected,PA/TRZ-POP membrane shows a more excellent water flux of 1414 L·m^(-2)·h^(-1)·MPa^(-1)than that of the state-of-the-art nanofiltration membranes,and without sacrificing dye rejection.The build of TRZPOP interlayer develops a new method for obtaining a high-flux nanofiltration membrane.

SYNTHESIS AND CHARACTERIZATION OF COMB-LIKE POLYMERS BEARING HETEROCYCLIC AZO GROUP AND MESOGENIC GROUP

The synthesis and characterization of a series of novel comb-like polymethacrylates bearing heterocyclic azo group and mesogenic group are described. The thermal properties of the polymers such as thermal stability and phase transition behavior were investigated by thermogravimetric analysis, differential thermal analysis and polarizing optical microscopy techniques. The experimental results show that all the synthesized polymers do not exhibit liquid crystallinity except the homopolymer of the mesogenic monomer MAPB2 and the glass transition temperatures of the polymers increase with increasing content of azo moiety in polymers linearly.

The Development of Thermal Conductive Polymer Composites for Heat Sink

The thermal and mechanical properties of the polyamide 6/boron nitride and polyphenylene sulfide/graphite composites have been investigated as a function of composition and size of fillers. The addition of highly thermal conductive h-BN and graphite gives rise to large increase （about 2 times） of thermal conductivity of individual polymer. In PPS/graphite system, the higher conductivity value was obtained when smaller graphites were added. Meanwhile, the tensile and flexural strength are reduced upon increasing filler loading.

STUDY OF MODIFIED AROMATIC POLYAMIDE SYNTHESIS AND CHARACTERISTICS OF CHLORINATED PPTA

Super pure 2,5-dichloroterephthaloyl dichloride (DDC) was prepared by chlorination andcontrolled by Gas Chromatography(GC) method. As a third monomer, DDC waspolycondensated into chlorinated PPTA together with terephthaloyldichloide (TPDC) andparaphenylene diamine (PPDA). The polycondensation conditions and the relationship betweenthe thermal behavior, viscosity, solubility, phase transition temperature of the modifiedpolyamide and the third monomer content discussed in this paper.

SYNTHESIS AND CHARACTERIZATION OF A NEW COMBLIKE POLYMER BASED ON POLY (VINYL METHYL ETHER-ALT-MALEIC ANHYDRIDE) BACKBONE

A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by LR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by C-13 NMR The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.

Synthesis and characterization of PEGylated comb-like cationic polymer by polycondensation and ATRP

PEGylated poly（2-（dimethylamino）ethyl methacrylate） with comb-like architecture was synthesized by two-step polymerization. First,poly（oligo（ethylene glycol） malicate）（POEGMA） bearing pendant hydroxyl groups was prepared by direct polycondensation of oligo（ethylene glycol） and malic acid in the presence of scandium triflate as chemoselective catalyst.Then the poly（2- （dimethylamino）ethyl methacrylate） side chains were grafted from the POEGMA backbone by atom transfer radical polymerization （ATRP） after the hydroxyl groups were modified into bromo-ester form,resulting in a PEGylated cationic copolymer with branched architecture.

Zwitterionic comb-like lipid polymers encapsulating linalool for increasing the fragrance retention time

Fragrances are widely used in cosmetics,apparel and detergents.However,the rapid evaporation of the aro ma shortens the useful life of the aromatic product.Therefore,improving the fragrance retention time of aromatic products and prolonging the service life of aromatic products are the key scientific problems that need to be solved in current aromatic products.In this study,zwitterionic comb-like lipid polymers were synthesized to encapsulate the fragrance molecule linalool.The results showed that the zwitterionic comb lipid molecules were capable of encapsulating more linalool than linear lipid molecules.At the same time,the zwitterionic comb-like lipid molecules also limited the slow release rate of the aroma,thereby increasing the fragrance retention time of the nano-fragrance.

Synthesis and characterization of well-defined comb-like branched polymers

Well-defined comb-like branched polymers having one branch in each repeating unit have been suc-cessfully synthesized by the coupling reaction of living polystyrene(PS)and polyisoprene(PI)anions with 1,1-diphenylethenyl(DPE)groups along PS backbone pre-pared via atom transfer radical polymerization(ATRP)of 4-vinylbenzyloxy benzophenone(Sc)followed by Wittig reaction.The resulting comb-like branched poly-mers were characterized by IR,1H-NMR,gel permeation chromatography(GPC)and static light scattering(SLS)in detail.The effect of living chains and DPE group molar ratio on grafting efficiency was discussed.The results show the coupling reaction of living chains and DPE groups was highly effective,and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups.Moreover,the effect of molecular weights of backbone(PSe)and PSLi or PILi on grafting efficiency was also discussed.The results show that when excess living polymers were used,the almost quantitative grafting efficiency could be achieved.

尼龙66材料热空气老化下的力学特性研究

目的研究获得尼龙66树脂在热空气老化下的力学特性。方法对尼龙66树脂采取110℃、1000 h的热空气老化方式进行试验,并对老化前后的样品进行表面观察,以及拉伸强度、悬臂梁缺口冲击强度、简支梁缺口冲击强度测试,进而获得尼龙66树脂在相应热空气老化下的力学特性变化规律。结果老化后,试样的颜色从乳白色变成姜黄色,试样表面完好,无龟裂、粉化;拉伸强度有所上升,平均强度保持率为105.1%;悬臂梁缺口冲击强度略有下降,平均强度保持率为94.7%;简支梁缺口冲击强度略有下降,平均强度保持率为93.9%。结论尼龙66树脂在相应热空气条件下会发生老化,但短时间内不会引起材料整体力学性能的明显下降。

聚酯酰胺的合成

聚酰胺是一类应用广泛的高分子材料,通常具有突出的热稳定性和机械耐久性,但也存在降解速率较慢的问题。聚酯材料则具有良好的可降解性和水解能力,但是机械性能稍微不足。近期新兴的聚酯酰胺是由酯和酰胺链段共聚而成的先进材料,它兼具聚酰胺和聚酯的优点,有望在药物输送、可降解塑料等领域得到应用,围绕合成聚酯酰胺的主要原料、制备聚酯酰胺的常规方法展开了讨论和总结,并对不同方法的优缺点进行了总结。

我国特种工程塑料产业发展现状及对策建议

特种工程塑料属于国家经济先导性产业,对于新能源汽车、5G通讯、航空航天、医疗等领域的发展起到关键推动作用。本文综述了国内特种聚酰胺[耐高温尼龙(PPA)/长碳链尼龙(LCPA)]、聚酰亚胺(PI)、聚苯硫醚(PPS)、液晶高分子聚合物(LCP)、聚醚醚酮(PEEK)、聚砜(PSF)的市场及技术发展现状,分析了特种工程塑料高端产品国产化瓶颈(单体制备、分离纯化技术、聚合工艺和关键装备)。针对国内发展特种工程塑料存在的技术壁垒高、原料短缺、产业结构不合理等问题,从强化创新、促进市场融合、污染防控等方面提出了发展建议。

添加改性超交联微孔聚合物提升聚酰胺反渗透膜脱盐性能

聚酰胺反渗透膜是目前广泛应用的一款商用化水处理膜。然而其表面活性层聚酰胺的结构致密,会导致水通量与截盐率出现“trade-off”现象。针对该问题提出,选择具有多孔结构的、亲水性超交联聚合物复合材料作为添加剂,在界面聚合过程中引入聚酰胺活性层中,为水分子提供更多水通道。同时,纯烃本质的超交联聚合物与聚酰胺的高度相容性,保证了反渗透复合膜的高效截盐性能。经过脱盐性能测试,结果显示添加3.0 mg PDA@HCP-B-SO_(3)H的反渗透复合膜具有最高的水通量为44.4 L·m^(-2)·h^(-1),截盐率高达99.6%。相比于聚酰胺反渗膜,3.0-PDA@HCP-B-SO_(3)H PA RO的水通量提升了26.5%,截盐率基本保持不变;相比于只嫁接-SO_(3)H的HCP-B-SO_(3)H PA RO,水通量提升了11.6%(35.0 L·m^(-2)·h^(-1)上升至39.8 L·m^(-2)·h^(-1)),截盐率基本持平。这说明添加具有多孔结构的、亲水性强的改性超交联聚合物作为添加剂,是一种十分有效地提升聚酰胺反渗透膜性能的方法。

生物基聚酰胺研究进展

介绍了各类生物基高分子材料,着重综述了生物基聚酰胺的主要合成路线以及开发应用现状,并就生物基聚酰胺的发展给出了相关建议。

聚苯硫醚/尼龙6共混物的结晶与熔融行为

用 DSC研究了不同组成比的聚苯硫醚 ( PPS) /尼龙 6( PA6)共混物中 PPS和 PA6组分的结晶与熔融行为及其相互作用的影响 ,结果表明 ,PPS在 PA6熔体存在下结晶温度明显提高 ,结晶峰形变窄 ;随 PA6含量增加 ,PPS的结晶温度移向高温 ,甚至 PPS成为分散相 ,这一作用还十分明显 ;而 PPS的熔融温度受共混影响较小 ,结晶了的PPS也使 PA6的结晶温度有所提高 ,但不如 PPS的结晶温度提高明显 ;当 PA6为分散相时 ,PA6的结晶温度才开始降低 ;随 PPS含量增加 ,PA6的起始熔融温度和熔点逐渐降低。

显微镜图像分析研究聚丙烯/尼龙1010共混物相结构及其性能

用扫描电子显微镜图像分析研究了聚丙烯/聚酰胺1010共混物及其部分相容体系的相形态结构,计算了表征相结构和尺寸的结构参数,如分散相的平均直径、平均弦长和分散相的质心相关距等.并分别讨论了聚丙烯/聚酰胺1010共混物及其部分相容体系的相形态以及其结构参数与共混物组成的关系.测定了聚合物及其共混物体系的力学性能,讨论了共混物组成与力学性能的关系.聚丙烯/聚酰胺1010共混物的拉伸模量与组成的关系较为复杂,但其部分相容体系的拉伸模量与组成呈线性关系.聚丙烯/聚酰胺1010及其共混物体系的屈服强度与共混物组成均呈线性关系.表征相结构的两相平均弦长比(l-1/-l2)与组成以及共混物体系力学性能与组成的关系,二者相似.同时讨论了体系力学性能随相尺寸等的变化规律.

PPO/PA合金的研制

比较了三条技术路线、PPO/PA质量比、各种抗冲击剂对PPO/PA合金性能的影响。应用FTIR、Molau实验、DSC曲线证实了改性反应原理及增容作用。结果表明 :在双螺杆挤出机中 ,聚苯醚 (PPO)与马来酸酐 (MAH)接枝反应 ,然后与聚酰胺 (PA66)、SEBS挤出共混 ,制成的PPO/PA合金 。

新型sPS/PA6/SsPS-H塑料合金的性能和形态结构

研究新型sPS PA6 SsPS H塑料合金的力学性能和微观形态结构 .间规聚苯乙烯 (sPS)的磺化产物磺化间规聚苯乙烯 (SsPS H)的加入明显地改善了sPS PA6(聚酰胺 6)二组分合金的力学性能 ,在sPS PA6 SsPS H重量组成为 80 2 0 5时 ,三组分合金的冲击强度最大 ,为 1 5 6kJ m2 ,约为纯sPS冲击强度的 3倍 DMA和SEM结果表明 ,SsPS H对sPS和PA6共混有良好的增容作用 ,它起到了降低合金的微相尺寸和加强相间界面粘结的作用 .此外 ,FTIR结果还表明SsPS H和PA6之间存在特殊相互作用 ,其作用方式是通过SsPS

衣康酸接枝PP对PA6／PP共混物增容作用机理的研究

以马来酸酐接枝ＰＰ（ＭＰＰ）作对照，用ＥＳＣＡ、ＳＡＸＳ、ＷＡＸＤ、ＳＥＭ、力学性能测试等手段，研究了衣康酸接枝ＰＰ（ＩＰＰ）对ＰＡ６／ＰＰ共混物的增容作用机理。证实共混物中有ＰＡ－ｃｏ－ｇＰＰ共聚物生成，讨论了ｇＰＰ和ＰＡ－ｃｏ－ｇＰＰ的结构与后者生成量和增容效率之间的关系，提出了ＰＡ－ｃｏ－ＭＰＰ和ＰＡ－ｃｏ－ＩＰＰ的增容作用模型。

纳米塑料研究进展

概述了纳米塑料的插层复合法、溶液 -凝胶法等主要制备方法、特点及其典型性能 。