含相变材料微胶囊的丙烯腈-丙烯酰胺共聚物的结构与性能

采用水相沉淀聚合法制备了丙烯腈(AN)-丙烯酰胺(AM)共聚物以及含有正十八烷微胶囊的AN/AM共聚物.采用傅立叶变换红外光谱(FT-IR)、核磁共振(1H-NMR)、差热分析(DSC)和X射线衍射(XRD)等方法对聚合产物进行了分析.结果表明,AM的引入改变了聚合物的环化机理,从自由基环化机理过渡为离子环化机理.随着共聚物中AM含量的增加,分解温度(Td)呈现出先降低后升高的变化趋势;但含有正十八烷微胶囊的AN/AM共聚物的Td则随着聚合物中微胶囊含量的增加而持续升高.共聚物的熔点(Tm) 随着AM或正十八烷微胶囊含量的增加而降低.     

碳纤维原丝用二元丙烯腈聚合物的合成及性能

设计合成了双功能共聚单体3-羧基-3-丁烯酰胺(CBA),采用溶液聚合的方法制备丙烯腈二元共聚物作为碳纤维前驱体,详细研究了单体配比对聚合反应、聚合物结构和预氧化性的影响。结果表明,随着单体投料中CBA含量的增加,聚合物中CBA含量增加,而相对分子质量和转化率均逐渐降低;红外光谱和差示扫描量热分析表明CBA单体能够通过离子机理引发环化,使预氧化温度降低60℃以上,且随着CBA单体含量的增加,离子环化反应加强,放热速率降低,有利于避免集中放热,CBA可以明显改善聚丙烯腈(PAN)的预氧化性能,有利于制备高性能碳纤维。     

高分子量二元丙烯腈聚合物的合成及性能

设计合成了双功能共聚单体3-酰胺基-3-丁烯酸甲酯(MMPA),以二元共聚合代替传统的三元共聚合,采用水相悬浮聚合的方法制备超高分子量丙烯腈二元共聚物作为碳纤维前驱体。采用傅里叶红外变换光谱仪、差示扫描量热分析仪和热失重分析仪详细研究了单体配比对聚合物相对分子质量、结构及预氧化性能的影响,结果表明,共聚单体MMPA的加入使预氧化温度由240℃降低至213℃,且投料中随着MMPA含量的增加预氧化温度降低,预氧化程度加深,合成的共聚单体MMPA能够有效改善丙烯腈聚合物的预氧化性能,宽化放热峰,避免放热集中;水相悬浮制备得到的丙烯腈聚合物相对分子质量高达106.7×10~4,有利于提高碳纤维的力学性能。     

含有低分子量聚乙二醇的丙烯腈-丙烯酸甲酯共聚物的结构与性能研究

在丙烯腈(AN)与丙烯酸甲酯(MA)的水相沉淀聚合过程中添加5%～30%的亲水性聚合物-聚乙二醇(PEG),合成含有PEG的丙烯腈基共聚物.采用傅立叶变换红外光谱(FTIR)、差示扫描量热仪(DSC)、热重分析(DTG)和X射线衍射分析(XRD)等方法对聚合产物进行了分析.结果表明,聚乙二醇不参与丙烯腈与丙烯酸甲酯的聚合反应,但对聚合物的热力学行为与结晶度产生一定的影响.随着PEG含量的增加,共聚物的分解温度先降低后升高,而熔融温度呈现出先升高后降低的变化趋势;聚合物的结晶度也随着PEG含量的增加先升高后降低.     

聚合温度对丙烯腈/丙烯酸甲酯共聚物结构与性能的影响

在不同聚合温度下,以水相沉淀聚合法合成了丙烯腈与丙烯酸甲酯共聚物。采用差示扫描量热分析(DSC)、元素分析(EA)、核磁共振波谱分析(NMR)等方法对聚合物的组成和结构进行了表征。结果表明,不同的聚合温度对丙烯腈与丙烯酸甲酯共聚物的热力学行为、组成及序列长度产生一定的影响。相同的单体投料比,随着聚合温度的升高,共聚物中丙烯腈的摩尔含量降低,丙烯腈的数均序列长度减小。     

聚合温度对丙烯腈/丙烯酸甲酯共聚物结构与性能的影响EI

在不同聚合温度下,以水相沉淀聚合法合成了丙烯腈与丙烯酸甲酯共聚物。采用差示扫描量热分析(DSC)、元素分析(EA)、核磁共振波谱分析(NMR)等方法对聚合物的组成和结构进行了表征。结果表明,不同的聚合温度对丙烯腈与丙烯酸甲酯共聚物的热力学行为、组成及序列长度产生一定的影响。相同的单体投料比,随着聚合温度的升高,共聚物中丙烯腈的摩尔含量降低,丙烯腈的数均序列长度减小。     

P(MMA-AN)的合成及其凝胶电解质的制备与性能

以甲基丙烯酸甲酯(MMA)和丙烯腈(AN)为单体,自由基引发聚合合成了聚(甲基丙烯酸甲酯-丙烯腈)[P(MMA-AN)]无规共聚物。采用红外光谱分析及元素分析法对共聚物的结构进行了表征。然后以此P(MMA-AN)无规共聚物为基体制备共聚物含量分别为30%、40%、50%(质量分数)的凝胶聚合物电解质(GPE)。采用交流阻抗法对其电性能进行表征。结果发现当MMA与AN投料比为1:3且共聚物在凝胶聚合物电解质中质量分数为30%时,GPE体系电导率达到最大值。     

溶剂蒸发法制备油核/聚合物壳微胶囊

通过溶剂蒸发法制备了十六烷/聚甲基丙烯酸甲酯核/壳结构微胶囊。SEM和光学显微镜照片显示,微胶囊呈球形,囊壁透明,表面光滑。系统研究表明,在相同条件下,随着PMMA用量的增加,微胶囊粒径增大,粒径分布变宽;随着搅拌速度的增加或/和稳定剂PVA量的增大,微胶囊的粒径减小,粒径分布变窄。     

电沉积参数对含憎水剂微胶囊复合镀铜层的影响研究

采用水相分离法制备出了粒径在2～10μm之间的液体憎水剂微胶囊,研究了含憎水剂微胶囊复合镀铜层的制备工艺,讨论了试样放置方式、电流密度、阴阳极距离、镀液中微胶囊溶液含量、电镀时间等电沉积参数对复合镀铜层中微胶囊含量的影响.研究表明,当试样水平放置时,复合镀铜层中微胶囊的含量明显增加;镀铜层中微胶囊含量随阴极电流密度、阴阳极距离、镀液中微胶囊溶液含量的增加呈现出先增加后减小的趋势;并且随着电沉积时间的增加,复合镀铜层中憎水剂微胶囊的数量增加.     

热胀性微胶囊的制备及其在水性木器功能涂料中的应用

以聚(丙烯腈-甲基丙烯酸甲酯-丙烯酸丁酯)为壳,对甲苯磺酰肼(TSH)为核,通过悬浮聚合法制得热胀性微胶囊。探讨了乳化剂和单体组成对微胶囊粒径、热膨胀性能的影响,并对其结构与性能进行了表征。红外谱图证实了AN-MMA-BA共聚物对TSH的成功包覆。微胶囊的横切扫描电镜图片显现出规整的核-壳结构。壳层共聚单体组成AN/MMA/BA为70%/20%/10%时所合成的微胶囊具有良好的热胀性能,含2%热胀性微胶囊的水性木器涂层经热处理后明显膨胀;热失重分析表明,较之于未加微胶囊的涂层,加入2%热胀性微胶囊涂层胶膜的失重起始温度提高了20℃以上,涂层热稳定性能提高,热分解温度范围为210～380℃,在250～320℃之间缓慢分解。     

Melt-processable acrylonitrile–methyl acrylate copolymers and melt-spun fibers containing MicroPCMs

Acrylonitrile–methyl acrylate (AN–MA molar ratio 85/15) copolymer and copolymers containing 5–25 wt% of microencapsulated phase change materials (MicroPCMs) were synthesized by aqueous redox initiated polymerization. MicroPCMs were incorporated into the copolymer at the step of polymerization. The copolymers were processed by environment friendly, solvent-free melt-spinning. The structures and properties of the copolymers and as-spun fibers containing MicroPCMs were characterized by Nuclear Magnetic Resonance (¹H NMR), Gel Permeation Chromatography (GPC), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TG), Scanning Electronic Microscope (SEM), X-ray Diffraction (XRD), and Melting Index (MI). The results show that the composition of AN–MA copolymer agrees well with the feeding ratio of AN and MA. The copolymers containing MicroPCMs can be processed at 200 °C. The crystalline enthalpies of the fibers containing 20 and 25 wt% of MicroPCMs are 21 and 25 J/g, respectively; and they increase steadily as the contents of MicroPCMs increase. Tensile strengths of the as-spun fibers are in the range of 1.0–3.2 cN/dtex. The fibers are potentially used as raw materials to fabricate thermo-regulated fabric for comfort clothing.     

Energy storage polymer/MicroPCMs blended chips and thermo-regulated fibers

The thermo-regulated sheath/core composite fibers containing 4–24 wt% of microencapsulated n-octadecane (MicroPCMs) were melt-spun with a 24-holes spinneret at a speed of 720 m/min. The polyethylene chips containing 10–60 wt% of MicroPCMs were used as the core and polypropylene chips were used as the sheath. The morphologies and properties of the chips and fibers were investigated by using SEM, DSC, WAXD and Melting Index tester etc. The microcapsules in the chips containing 10–40 wt% of MicroPCMs are evenly inserted inside the polymer matrix and their respective phase change temperatures are almost the same. The enthalpies rise steadily as the content of MicroPCMs increased from 10 wt% to 40 wt%. The efficiency of enthalpy of the chip containing more than 30 wt% MicroPCMs depends on the extruding procedure. For the same MicroPCMs content, the efficiency of enthalpy of the chip fabricated directly with MicroPCMs and polyethylene are significantly lower than that of the chips fabricated with polyethylene, MicroPCMs and chips containing MicroPCMs by progressively increase the MicroPCMs contents. Nonetheless, the spinnability of the chips decrease as the contents of MicroPCMs exceed 50 wt%. The micrographs of the spun fibers containing 4–24 wt% of MicroPCMs also indicate that the core of the fibers was evenly surrounded by the sheath component. The heat absorbing and evolving temperatures of the fibers remain unchanged with the increase of MicroPCMs content and keep at approximately 32 and 15^∘C, respectively. The enthalpy, tensile strength and strain of the fiber containing 20 wt% of MicroPCMs are 11J/g, 1.8cN/dtex and 30.2%, respectively. The spun fibers can be used for the production of fabric materials.     

含 Sm 聚合物的制备及荧光性质

用 Sm_2O_3制备了甲基丙烯酸钐和辛酸钐。通过添加或交联制得了含 Sm 的甲基丙烯酸和甲基丙烯酸甲酯共聚物。测定了 Sm 盐的元素分析、IR、TG、DTA 和它们在溶液中的荧光性质。研究了含 Sm聚合物的力学性能和荧光性质。     

Water sorption behaviour of polymeric systems based on tetrahydrofurfuryl methacrylate

Earlier research has described the water absorption behaviour, drug release and biological properties of a room temperature polymerizing system based on poly(ethyl methacrylate) (PEM) powder and tetrahydrofurfuryl methacrylate (THFM) monomer. This work has been extended, with respect to water sorption behaviour, by replacing the monomer to various extents with hydroxyethyl methacrylate (HEMA), and poly(ethyl methacrylate) by ethyl methacrylate (EM)-THFM copolymers. Replacing the THFM with HEMA, and gelling with PEM, increased the diffusion coefficient progressively. The replacement of PEM by EM-THFM copolymers, when gelled with THFM monomer, substantially reduced equilibrium water uptake, and increased diffusion coefficients. However, with HEMA monomer, equilibrium uptake was unaffected, but the diffusion coefficient decreased with increasing THFM content of the copolymer. This is due to a complex interaction of THFM cross-linking the copolymer, and the effect of EM on the water uptake. Heat polymerizing the PEM-THFM system reduced equilibrium uptake and the diffusion coefficient, compared with the room temperature polymerizing system; this could reflect molecular weight differences. © 1999 Kluwer Academic Publishers     

储热调温海藻酸钠/聚乙烯醇共混膜的制备及性能研究

用原位聚合法制备了苯乙烯/二乙烯苯囊壁的正十八烷微胶囊,并将其添加到海藻酸钠/聚乙烯醇(SA/PVA)共混溶液中,制成具有调温性能的共混膜,采用SEM、DSC、FT-IR等对膜的结构和性能进行了测试。结果表明,正十八烷微胶囊的加入,对由两种高聚物共混而制成的膜的形态有一定的影响,共混膜的表面出现孔洞现象;随着正十八烷微胶囊含量的增加,共混膜的熔融热焓和结晶热焓逐渐增加,但其断裂强力和断裂伸长率却逐渐降低。     

Wetting behavior of oleophobic polymer coatings synthesized from fluorosurfactant-macromers

Architecturally similar monomers were copolymerized with a water-oil discriminate fluorosurfactant to create hydrophilic-oleophobic coatings. Acrylic acid, hydroxyethyl methacrylate, and methyl methacrylate were used as comonomers with the fluorosurfactant macromer. The homopolymers of the selected comonomers are water-soluble, water-swellable, and water-insoluble, respectively, thus coupling the surfactant monomer in varying concentration within polymers of varying hydrophilicity. Wetting behavior of water and hexadecane were examined as a function of copolymer composition, thus revealing critical structure-property relationships for the surfactant-based system. Acrylic acid copolymers and hydroxyethyl methacrylate copolymers both exhibited a hexadecane contact angle which exceeded the water contact angle. This condition predicted an ability to "self-clean" oil-based foulants. The most oleophobic of the self-cleaning copolymers had an advancing hexadecane contact angle of 73° and an advancing water contact angle of 40°. It was determined that the advancing and receding water and hexadecane contact angle response varies montonically for each copolymer type as the surface concentration of the surfactant is varied. Comparing between copolymer types revealed large differences in wetting response. Methyl methacrylate copolymers with 2.8 mol % surfactant had advancing water contact angle 82° and advancing hexadecane contact angle 26°, which is neither oleophobic nor self-cleaning. In contrast, acrylic acid copolymers with 3.1 mol % surfactant had advancing water contact angle of 44° and advancing hexadecane contact angle of 52°, creating a self-cleaning coating. Thus, the nature of the comonomer exerts a greater influence than the surfactant content on the wetting behavior and self-cleaning ability of the final coating.     

SG增容PA6/sPS共混体系的形态结构与力学性能

采用一系列不同甲基丙烯酸环氧丙酯(GMA)含量的苯乙烯-甲基丙烯酸环氧丙酯共聚物(SG)增容尼龙6(PA6)/间规聚苯乙烯(sPS)(80/20)共混物,通过扫描电镜及拉伸实验考察了SG共聚物中GMA的含量对共混物形态结构及力学性能的影响。形态观察显示,SG共聚物可以有效地降低PA6/sPS共混物中分散相的尺寸,增加两相界面间的粘接力;SG共聚物中GMA的含量对其增容效果有较大影响,质量分数为5%左右时,SG共聚物对PA6/sPS共混物的增容效果最佳。拉伸实验结果表明,PA6/sPS共混物的拉伸强度及模量随着SG共聚物的加入而增加,但其断裂伸长率在较高SG含量时则有所下降。     

聚合物P(TMSPMA-MMA-BA)的合成及聚合反应动力学

为改进甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)共聚物的性能,利用乳液共聚合方法,将γ-甲基丙烯酰氧丙基三甲氧基硅烷(TMSPMA)引入共聚物分子链。用红外光谱仪和热重分析仪对共聚物进行了表征;研究了反应温度、引发剂浓度、乳化剂浓度和TMSPMA浓度对乳液共聚合反应速率的影响。红外谱图中1144cm-1处Si-O-Si键的吸收峰表明TMSPMA与MMA/BA发生了共聚合反应;引入TMSPMA的共聚物在250℃以前热性能稳定,MMA/BA共聚物的起始分解温度得到提高;升高反应温度、增大引发剂或乳化剂摩尔浓度及降低TMSPMA摩尔浓度都可以提高聚合反应速率。得到了聚合反应活化能和动力学方程。     

Direct probe-atmospheric pressure chemical ionization mass spectrometry of cross-linked copolymers and copolymer blends

Complex copolymers are heated to slowly increasing temperatures on a direct probe (DP) inside the plasma of the atmospheric pressure chemical ionization (APCI) source of a quadrupole ion trap. Slow heating allows for temporal separation of the thermal degradation products according to the stabilities of the bonds being cleaved. The products released from the DP are identified in situ by APCI mass spectrometry and tandem mass spectrometry. DP-APCI experiments on amphiphilic copolymers provide conclusive information about the nature of the hydrophobic and hydrophilic components present and can readily distinguish between copolymers with different comonomer compositions as well as between cross-linked copolymers and copolymer blends with similar physical properties. The dependence of DP-APCI mass spectra on temperature additionally reveals information about the thermal stability of the different domains within a copolymer.     

9,9-二(丙酸二甲氨基乙酯)芴共聚物的合成及荧光性能

采用迈克尔加成反应制备了单体2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴(FDMAEA);采用Suzuki偶合反应制备了不同FDMAEA结构单元含量的醇溶性9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物(PFDMAEA)。通过核磁共振、凝胶渗透色谱、溶解性测试、紫外-可见光光谱、荧光发射光谱等对其进行了分析研究。结果表明,成功合成了2,7-二溴-9,9-二(丙酸二甲氨基乙酯)芴及9,9-二(丙酸二甲氨基乙酯)芴-9,9-二辛基芴共聚物。该共聚物在极性溶剂,如甲醇中具有良好的溶解性。由于含有DMAEA支链的PFDMAEA主链容易扭曲,共轭长度变短,共聚物的紫外吸收光谱和荧光光谱随着FDMAEA含量的增加而发生蓝移。荧光发光光谱研究表明,溶剂的极性、溶液的浓度、温度和pH值对共聚物的发光性能有很大的影响。随着溶剂极性增大,共聚物的荧光发射强度不断增加。荧光发射强度随溶液浓度的增加先增加后降低,随着溶液温度的上升而降低。当溶液pH值由1增大到14时,荧光强度不断降低,直至淬灭。