聚乳酸/乙烯-醋酸乙烯酯共聚物共混物的形态与黏弹行为

熔融共混制备了不同组分比的聚乳酸(PLA)/乙烯-醋酸乙烯酯共聚物(EVA)共混物,采用扫描电子显微镜(SEM)、溶剂选择性蚀刻和旋转流变仪研究了共混物不相容的相形态及其黏弹响应.研究结果表明,PLA/EVA共混物为典型的热力学不相容体系,两基体组分间的界面张力约为2.2 mN/m;因此随组分比的不同,共混物表现出"海-岛"分散和双连续的不相容相形态;体系中EVA的相反转浓度约为50 wt%～60 wt%,这与黏性模型对相反点预测的结果一致;与双连续相形态的体系相比,乳液模型能够更好的描述具有"海-岛"分散形态的体系的线性黏弹响应,共混体系相对较宽的相反转区域主要源于两组分间较大的弹性比以及EVA自身的屈服行为.     

碳系导电填料混杂填充聚合物共混体系的导电逾渗模型

以排除体积理论为基础,提出了3种碳系导电填料混杂填充聚合物共混体系的导电逾渗模型,并利用三维图和二维图对导电逾渗模型进行了描述.选用炭黑、聚团状碳纳米管和阵列碳纳米管3种导电填料,以聚碳酸酯(PC)/苯乙烯-丙烯腈共聚物(SAN)(70∶30,质量比)和PC/聚苯醚(PPO)(70∶30,质量比)2个共混体系进行研究,通过不同导电填料在单一聚合物及其共混物中逾渗值的测量,对导电逾渗模型公式的各个参数进行计算和修正.导电逾渗模型预测结果与样品实际电阻率基本吻合,证明了模型的普适性和实用价值.对于基体相不变的系列聚合物共混体系,可以通过任意一种导电填料在共混体系中的逾渗值及在基体相聚合物中的逾渗值之比得到模型公式的相关参数,从而极大地方便了模型的推广和应用.     

受限条件下不相容聚合物共混物的形态演变研究进展

不相容聚合物共混物形成的相结构决定着共混材料的各项性能。近几年,研究发现不相容聚合物共混物受限条件下的相结构与非受限条件下的相结构有很大不同。本文从理论模型、实验结果以及影响因素(包括受限程度、组分比、剪切速率和粘弹性)等方面,综述了近年来开展的受限条件对不相容聚合物共混物相结构影响的研究进展,指出了现有研究的一些不足之处并展望了该领域的发展趋势。     

聚合物二元共混物拉伸强度混合规则的改进模型

改进了关于聚合物二元共混物拉伸强度混合规则的模型 ,保留了原模型中分别表征共混物界面和相结构对共混物拉伸强度产生影响的两个因子F和M .用此模型处理了三个共混体系的拉伸强度数据 ,反算出共混体系的界面强度因子F和相结构强度因子M ,结果表明 ,该改进模型的预测值与实验结果相符程度与原式几无差别 ,但使F和M的物理意义更为明确、合理 ,其相关系数也有所增大     

聚丙烯/POE共混组成对材料断裂行为的影响

采用基本断裂功(EWF)方法对聚丙烯(PP)/聚烯烃弹性体(POE)共混物的注射双边缺口拉伸试样的断裂行为进行了研究,比较了不同POE含量对共混物各断裂参数的影响.结果表明,PP和用量为5phr POE的共混物都可完全满足EWF方法的要求,共混物的断裂韧性-比基本断裂功we,较PP有显著提高;POE用量为10phr以上的共混物则出现明显的成颈现象而限制了EWF方法的应用;PP和各种POE用量的共混物都得到了其屈服所需要的比基本断裂功we,y和比塑性功β′wp,y.     

两相聚合物共混体系的相逆转及其力学模型的研究——Ⅰ.模量与组成关系

本文从连续相变理论的角度,提出一个与共混组成相关的权重因子,应用对数加和规则,建立了能预测共混体系相逆转的力学模型,该模型对于描述共混体系的模量与组成关系具有良好的准确性和普适性。     

共连续型高分子共混物性能预测模型的研究进展

共连续结构是不相容高分子共混物体系中的典型相结构。共连续共混物的机械性能、热性能、电性能以及阻隔性能等均由于两相的协同作用而得到显著改善。预测共连续共混物的性能无论是在工业生产还是在学术研究上都具有重要的意义。本文针对共连续共混物目前常用的性能预测模型进行了总结归纳,包括串并联模型、Kerner模型、Davies模型、...     

PTHF-b-PMMA/PVC共混体系的相容性和结晶行为

研究了具有焓效应的聚四氢呋喃-聚甲基丙烯酸甲酯两嵌段共聚物与聚氯乙烯PTHF-b-PMMA/PVC)共混体系的相容性和结晶行为. 结果表明, 其相容性比AB/A型嵌段共聚物共混体系的相容性要好得多; 与PTHF部分相容的PVC对PTHF微区的结晶行为可产生很大的影响. 应用有关理论和模型很好地解释了结晶行为的这种变化.     

线性聚酯酰胺对聚碳酸亚丙酯的改性

通过己内酯和氨基己酸开环、缩合反应制备了酯段含量为81%的线性聚酯酰胺（PEA）,并用熔融共混的方法制备了PEA/聚碳酸亚丙酯（PPC）共混物,考察了PEA的引入对共混体系相容性、热力学稳定性和机械性能的影响。 结果表明,PEA与PPC之间有较好的相容性,共混物的热力学稳定性比PPC有显著提高,当PEA质量分数为3%时,共混体系的起始分解温度（T-5%）和最大分解速率时的温度（Tmax）比PPC分别提高了52.7%和46.4%。 通过调节PEA的含量可以使共混体系同时达到增强和增韧的效果。     

PC/ABS共混物的PGC-MS定量分析

采用裂解/气相色谱-质谱联用方法(PGC-MS)对制备的一系列已知配比的PC/ABS共混物进行分析。实验比较了650、750℃裂解温度下共混物的裂解质谱总离子流图,选择PC/ABS共混物的快速鉴定的裂解温度为750℃;通过对已知PC/ABS配比的共混物的特征裂解碎片进行定量分析,发现当共混物中ABS和PC的质量比不大于20∶100时,特征裂解碎片苯乙烯与苯酚的峰面积之比与共混物中ABS/PC的配比呈线性关系,该现象可作为PC/ABS共混物定量分析的依据。     

Combining configurational entropy and self-concentration to describe the component dynamics in miscible polymer blends

We provide a new approach to describe the component segmental dynamics of miscible polymer blends combining the concept of chain connectivity, expressed in terms of the self-concentration, and the Adam-Gibbs model. The results show an excellent agreement between the prediction of our approach and the experimental data. The self-concentrations obtained yield length scales between 1 and 3.2 nm depending on the temperature, the flexibility of the polymer, expressed in terms of the Kuhn segment, and its concentration in the blends, at temperatures above the glass transition range of the blend.     

Probing molecular-level surface structures of polyethersulfone/pluronic F127 blends using sum-frequency generation vibrational spectroscopy

We blended Pluronic F127 into polyethersulfone (PES) to improve surface properties of PES, which has been extensively used in biomaterial and other applications. The molecular surface structures of PES/Pluronic F127 blends have been investigated by sum-frequency generation (SFG) vibrational spectroscopy. The molecular orientation of surface functional groups of PES changed significantly when blended with a small amount of Pluornic F127. Pluronic F127 on the blend surface also exhibited different features upon contacting with water. The entanglement of PES chains with Pluronic F127 molecules rendered the blends with long-term surface stability in water in contrast to the situation where a layer of Pluronic F127 adsorbed on the PES surface. Atomic force microscopy (AFM) and quartz crystal microbalance (QCM) measurements were included to determine the relative amount of protein that adsorbed to the blend surfaces. The results showed a decreased protein adsorption amount with increasing Pluronic F127 bulk concentration. The correlations between polymer surface properties and detailed molecular structures obtained by SFG would provide insight into the designing and developing of biomedical polymers and functional membranes with improved fouling-resistant properties.     

海藻酸钠-硫酸软骨素共混膜的结构及性能研究

利用溶液共混法成功制备了新型生物膜材料-硫酸软骨素共混膜,通过红外光谱、X-射线衍射、原子吸收光谱和扫描电镜对共混膜的结构进行了表征,并测定了不同配比共混膜的抗张强度、断裂伸长率,吸水率,同时考察了介质pH值和离子强度对共混膜吸水率的影响。结果表明:共混膜中海藻酸钠、软骨素之间具有较强的相互作用和良好的相容性,共混膜具有良好的力学性能。作为一种潜在的生物材料可望在生物医学领域得到应用。     

胶原蛋白-葡甘聚糖-壳聚糖(CKCS)共混膜的表面性质

生物材料植入人体后,其生物学性能主要由人体组织和体液等与材料表面的相互作用决定。本文通过对CKCS-2的CKCS-5膜的X-射线光电子能谱分析和静态接触角测定,考察胶原蛋白-葡甘聚糖-壳聚糖共混膜的表面性质,为共混膜在生物医学领域的应用提供理论依据。     

三元乙丙橡胶环氧化增韧聚对苯二甲酸丁二酯的研究

三元乙丙橡胶环氧化增韧聚对苯二甲酸丁二酯的研究王学会，张会轩，王新华，王志刚，蒋俊光，姜炳政（吉林工学院化工系，长春，１３００１２）（中国科学院长春应用化学研究所）关键词三元乙丙橡胶，环氧化，ＰＢＴ，增韧作用，共混物聚对苯二甲酸丁二酯（ＰＢＴ）具有优...     

Polymer blend membranes of sulfonated poly(arylene ether ketone) for direct methanol fuel cell

The blend membranes of sulfonated poly(arylene ether ketone) (sPAEK) (IEC = 1.0 mequiv./g)/Nafion^® and the blend membranes of sPAEK (IEC = 1.0 mequiv./g)/sPAEK (IEC = 1.7 mequiv./g) were prepared. sPAEK with low IEC was introduced to reduce the methanol permeability through the membrane. Morphology, water uptake, proton conductivity and methanol permeability of the blend membranes were investigated by SEM, AFM, AC impedance spectroscopy and permeability measuring instrument. The cross-sections of blend membranes showed phase-separated morphologies. The effect of phase-separated morphology on the properties of blend membranes was investigated. The properties like water uptake, proton conductivity, and methanol permeability of sPAEK/Nafion^® blend membranes showed similar values with sPAEK and properties of sPAEK/sPAEK blend membranes showed intermediate values of two polymers due to the difference in morphology of the blend membranes. sPAEK/sPAEK blend membranes showed relatively high proton conductivity and lowered methanol permeability compared to Nafion^®. sPAEK/sPAEK blend membranes could be a competent substitution for Nafion^®.     

Biological recycling of plastics containing ester bonds

Biodegradable blend plastics such as polycaprolactone (PCL)-conventional plastics blends, PCL-polystyrene blend foams, PCL-poly-3-hydroxybutyrate (PHB) blends, PCL-raw cornstarch (CS) blends and PCL-CaCO₃ blends were developed. It was suggested that the thermophilic composting of biodegradable plastics containing PCL was one of powerful technologies for recycling of biodegradable plastics. Furthermore, we tried to get useful products from biodegradable plastics by microbial fermentation processes. Polypropylene (PP)-CS blend and PCL-CS blend plastics were aerobically converted into ethanol by Bacillus polymyxa. PHB and PP-CS blend and PCL-CS blend plastics were anaerobically converted into some organic acids and methane gas by mixed microbial cultures with a methanogenic bacterium.     

超临界CO2辅助制备聚苯乙烯/尼龙1010共混物及其结晶形态

超临界CO2辅助制备聚苯乙烯/尼龙1010共混物及其结晶形态;超临界CO2;插嵌;共混;尼龙1010;苯乙烯;附生结晶     

聚醚砜/酚酞基聚醚砜共混相容性及凝胶特性研究

采用混合热焓法和稀溶液粘度法预测了聚醚砜/酚酞基聚醚砜体系相容性,并观察了聚醚砜/酚酞基聚醚砜共混制膜液的凝胶值与共混比的关系.聚醚砜/酚酞基聚醚砜为部分相容体系,其相容性与组成有关.共混制膜液的凝胶值受共混组成的影响,并非纯组分制膜液凝胶值的线性加和.     

PEU/PES共混膜的制备工艺条件研究

利用L-S相转化法将聚醚型聚氨酯（PEU）和聚醚砜（PES）共混,以聚乙二醇（PEG）为添加剂,制备PEU/PES共混膜,并通过测定比较共混膜的结构与性能.结果表明：聚合物浓度、共混组成比、添加剂种类与浓度是影响PEU/PES共混膜性能的主要因素.