壳聚糖/玉米醇溶蛋白膜液的流变与膜热性能

将壳聚糖与玉米醇溶蛋白按不同质量比共混得到了系列共混膜液(C/Z-0、C/Z-1、C/Z-3、C/Z-5)并通过溶液浇铸制得相应共混膜。通过旋转流变仪、SEM及DSC分析了不同质量比对共混膜液体系的流变特性、共混膜的微观结构及共混膜热特性的影响。结果表明:不同质量比的共混膜液均具有假塑性,且随着玉米醇溶蛋白质量分数的增加,膜液的稠度系数减小,流动指数增大(从0.849增加到0.882),共混膜液的活化能均逐渐升高。动态频率扫描流变学分析表明,储能模量和损耗模量均表现出对频率的依赖性,且随着玉米醇溶蛋白质量分数的增加,两者数值均上升,此外,交叉点向低频方向移动,表明分子间氢键作用力增强。C/Z-1共混膜中壳聚糖与玉米醇溶蛋白分子结合紧密,相容性好,这也导致了共混膜热稳定性的提高。     

负载茶多酚的三元共混膜液与膜性能分析

将不同质量分数的活性成分茶多酚加入到壳聚糖/玉米醇溶蛋白共混膜液中，采用溶剂浇铸法制备得到一种三元共混膜。分析茶多酚对壳聚糖/玉米醇溶蛋白膜液静态和动态流变学特性、粒径分布以及凝胶强度的影响；测定三元共混膜的机械性能和阻隔性能；同时对共混膜进行形貌、红外、晶体学和热力学分析。结果表明：茶多酚与成膜基质之间的交互作用使膜液中产生了高度纠缠网络结构，有利于均匀稳定共混膜的形成；负载适量茶多酚对膜性能具有良好的改善作用，当茶多酚负载量为1%时，膜材料具有最佳的抗拉强度10.966 Mpa；SEM和XRD结果显示茶多酚与壳聚糖、玉米醇溶蛋白之间发生了强烈的相互作用，具有良好的相容性；FT-IR图谱显示茶多酚与成膜基质之间产生了氢键相互作用；通过热力学分析发现负载茶多酚质量分数为0.5%和2%时，共混膜具有较高的热稳定性。     

油酸对壳聚糖/玉米醇溶蛋白复合膜液流变及膜性能的影响

为了提高壳聚糖/玉米醇溶蛋白膜的机械性能，将壳聚糖液与玉米醇溶蛋白液共混，向其中加入0%、15%、30%、45%（w/w）的油酸改性，研究膜液的粒径、zeta电位、静态和动态流变特性；然后，分析油酸添加量对膜阻隔性能，机械性能和相容性的影响。结果表明：添加油酸后，膜液体系粒径增大、分散均匀，添加30%油酸的膜液分散性更好，PDI为0.34，粒径为1307.5nm。随着油酸含量增大，膜液粘度减小，流动指数增大，弹性模量和粘性模量增加。OA-30膜机械性能较好，抗拉强度达到36.37MPa，断裂延伸率达到22.32%。膜的阻隔性增强，水蒸气、氧气透过率分别降低了44.21%和66.52%。复合膜中壳聚糖与玉米醇溶蛋白分子相容性好，表面光滑平整。综上所述，油酸改性改善了壳聚糖/玉米醇溶蛋白复合膜性能。     

油酸对壳聚糖/玉米醇溶蛋白膜性能的影响

为了提高壳聚糖/玉米醇溶蛋白膜的机械性能,将壳聚糖液与玉米醇溶蛋白液共混,向其中加入含量为0、15%、30%、45%(以复合膜液中壳聚糖和玉米醇溶蛋白的总质量为基准,下同)的油酸进行改性,制得复合膜液。考察了膜液的粒径、Zeta电位、静态和动态流变特性;分析了油酸添加量对膜阻隔性能、机械性能和相容性的影响。结果表明:添加油酸后,膜液体系粒径增大、分散均匀,添加30%油酸的膜液分散性更好,PDI为0.34,粒径为1307.5 nm。随着油酸含量增大,膜液黏度减小,流动指数增大,弹性模量和黏性模量增加。含30%油酸的膜机械性能较好,抗拉强度为36.37 MPa,断裂伸长率为22.32%。与不含油酸的膜相比,添加45%油酸膜的阻隔性增强,水蒸气、氧气透过率分别降低了44.21%和67.52%。复合膜中壳聚糖与玉米醇溶蛋白分子相容性较好,表面光滑平整。     

负载茶多酚的三元共混膜的制备及性能

以壳聚糖、玉米醇溶蛋白、茶多酚为原料,采用溶剂浇铸法制备得到一种三元共混膜。考察了茶多酚负载量(基于壳聚糖和玉米醇溶蛋白的总质量,下同)对壳聚糖/玉米醇溶蛋白膜液静态和动态流变学特性、粒径分布以及凝胶强度的影响。采用SEM、FTIR、XRD及DSC对共混膜进行了表征,并测定了三元共混膜的机械性能和阻隔性能。结果表明,茶多酚与成膜基质之间的交互作用使膜液中产生了高度纠缠网络结构,有利于均匀稳定共混膜的形成。负载适量茶多酚对膜性能具有良好的改善作用,当茶多酚负载量为1%时,共混膜具有最佳的抗张强度[(10.966±2.111)MPa]。茶多酚与壳聚糖、玉米醇溶蛋白之间发生了强烈的相互作用。此外,茶多酚负载量为0.5%和2.0%时,共混膜具有较高的热稳定性。     

丝素/羧甲基壳聚糖共混膜的结构性能探讨

将含有甘油和戊二醛的丝素与羧甲基壳聚糖按一定比例混合,制得丝素/羧甲基壳聚糖共混膜,对共混膜的结构与性能进行了探讨。结果表明:随着羧甲基壳聚糖含量的增加,共混膜的透气率增大,加入交联剂戊二醛有效地改善了共混膜的力学性能,但其透气率有所降低;当丝素与羧甲基壳聚糖的质量比为4/1时,共混膜的断裂强度最大,力学性能较好,共混膜相容性较好,其断面光滑、致密。制备丝素/羧甲基壳聚糖共混膜的较佳条件为:丝素中的甘油质量分数为15%,戊二醛质量分数为0.075%,丝素与羧甲基壳聚糖质量比为4/1。     

氧氟沙星-壳聚糖-明胶共混膜的制备及表征

制备了壳聚糖 明胶共混膜 ,测定了壳聚糖 明胶共混膜的抗张强度 ,并以抗张强度最大的壳聚糖 明胶共混膜为载体 ,氧氟沙星为模型药物制得具有抗菌性能的氧氟沙星 -壳聚糖 -明胶共混膜。通过红外光谱 (FT -IR) ,X射线衍射 (X ray) ,扫描电子显微镜 (SEM)表征了共混膜的特性。结果表明 :明胶质量分数为 2 5 %时 ,壳聚糖 明胶共混膜的抗张强度最大 ,达 5 5MPa。壳聚糖、明胶、氧氟沙星三者在共混膜中有很好的相容性 ,并且形成了分子间氢键     

再生丝素/壳聚糖共混纳米纤维的结构与性能

以98%的甲酸为溶剂,不同质量分数的再生丝素溶液和3.5%的壳聚糖溶液以质量比70∶30共混静电纺丝。测定了壳聚糖的含量对共混膜的结构及力学、溶解等性能的影响。结果表明:随着壳聚糖相对含量的增加,丝素β化程度提高,纤维结晶度增大,丝素与壳聚糖以70∶30共混时的溶失率最小;甲醇处理后,溶失率明显降低;共混纳米纤维的断裂强度随着壳聚糖相对含量的增大而增加,柔软性也逐渐提高;共混纤维膜具有优异的抗菌性。     

明胶对明胶/壳聚糖共混膜性能影响的研究

采用溶液共混法制备出了一系列明胶／壳聚糖共混膜,并考察了制备条件对膜性能的影响。结果表明：明胶的溶解方式对吸水率和溶胀比影响很小;随明胶分子量增加,共混膜的吸水率和孔洞体积增大;而随共混体系中明胶质量分数的增加,吸水率和孔洞体积亦增加,但溶胀比下降。     

丝素/羧甲基壳聚糖共混膜的结构与性能

利用丝素(SF)与羧甲基壳聚糖(CMCS)共混制取不同比例的SF/CMCS共混膜。研究了CMCS诱导的丝素构象转变行为,测试了共混膜的吸湿性、透湿性和保水性。当CMCS的质量分数为5%时,共混膜中丝素的构象以β-折叠为主;当CMCS的质量分数为10%时,共混膜中丝素的构象由β-折叠向α-螺旋发生转变;当CMCS的质量分数达到15%时,共混膜中丝素的构象向无规卷曲发生转变。当CMCS质量分数小于15%时,共混膜中SF与CMCS具有良好的相容性,溶胀度较小,吸湿性随CMCS含量的增加而迅速降低。     

Preparation and characterization of alginate/gelatin blend fibers

Alginate and gelatin blend fibers were prepared by spinning their solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl₂ and ethanol. The structure and properties of the blend fibers were studied with the aid of infrared spectra, scanning electron micrography, X‐ray diffraction, and thermogravimetric analysis. Mechanical properties and water‐retention properties were measured. The best values of the tensile strength and breaking elongation of blend fibers were obtained when gelatin content was 30 wt %. The water‐retention values of blend fibers increase as the amount of gelatin is raised. The structural analysis indicated that there was strong interaction and good miscibility between alginate and gelatin molecules resulted from intermolecular hydrogen bonds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1625–1629, 2005     

油菜籽蛋白质与琼脂复合膜的性能研究

以油菜籽蛋白质和琼脂粉为原料,采用浇铸法制备共混膜,考察了琼脂用量、热处理、pH以及甘油用量对薄膜机械性能与光学性能的影响。结果表明,对薄膜物理性能影响较显著的因素为琼脂用量、pH和甘油用量,热处理影响不明显。成膜的最佳条件为琼脂用量70%,蛋白质含量为30%,pH=10.0,甘油添加量0.8 g,热处理温度50℃,在该条件下制备的复合膜的抗拉强度和断裂伸长率分别达到35 MPa和10%,较单一的蛋白质薄膜提高了6~10倍;透明度由2.88提高到0.93。     

Compatibilization of an immiscible blend of EPDM and POM with an Ionomer

Immiscible blends of ethylene-propylene-diene-monomer (EPDM) and polyoxymethylene (POM), when EPDM is the major phase were compatibilized on the addition of an ionomer, poly(ethylene-co-methacrylic acid). The inclusion of the ionomer reduced the interfacial tension between the two phases, such that the diameter of the POM domains were significantly reduced to between 0.5 and 2 μm, typical of that required to toughen ductile polymers. The mechanical properties of the resultant compatibilized blends were significantly enhanced with increases in Young's modulus (↑54%), tensile strength (σ, ↑139%), elongation at break (ε, ↑97%), and tensile toughness (↑500%) with increasing ionomer content, relative to EPDM rubber alone. The ShoreA hardness of the compatibilized blend was 70.1 compared with 56.8 for the immiscible binary blend and, 50.2 for neat EPDM rubber.     

Thermal properties of a thermoplastic polyimide blend

Differential scanning calorimetry and dynamic mechanical analysis of blends of a new thermoplastic polyimide (TPI) and poly(ether imide) (PEI) have confirmed the full miscibility of the system over the whole composition range. Annealing of the blends above the glass transition temperature of TPI, but below its crystallization temperature, did not produce a shift in the glass transition, while physical ageing of the annealed blends also failed to reveal any indication of phase separation. The rate of crystallization of TPI was slowed by the addition of PEI, and the temperature of the maximum crystallization rate shifted upwards. The β‐relaxation behavior of the blends followed a linear trend between the response of the component polymers, while the low‐temperature γ‐relaxation was unchanged by blending. The time scale of physical ageing of the blends did not behave in a linear fashion, and the enthalpy loss on ageing also deviated from the average. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 543–552, 1999     

Binary polymer blend of ArPTU/PI with advanced comprehensive dielectric properties and ultra-high thermally stability

Flexible high-temperature polymeric dielectrics with advanced dielectric properties are urgently demanded in various applications. In this work, series of polymer blend films were prepared from aromatic polythiourea (ArPTU) and polyimide (PI). The experimental results revealed that the blend films were properly engineered to achieve higher breakdown strength, greater dielectric constant, and larger energy density than pure PI film. For instance, the optimum property was obtained from the blend film with 10 wt% ArPTU, exhibiting prominent dielectric properties (K = 4.52, E_b = 443 MV/m), enhanced energy density (4.00 J/cm³) as well as excellent heat resistance (T_g = 419°C). In addition, stable dielectric properties at broad temperature range from −50 to 250°C were also acquired. It is deduced that the good compatibility from ArPTU and PI with similar polarity are responsible for the improved properties. The superior comprehensive properties which combine the advantages of ArPTU and PI suggest the potential applications of ArPTU/PI blend film in high-temperature dielectric areas.     

Preparation and characterization of soy protein isolate–carboxymethylated konjac glucomannan blend films

To improve the mechanical and water vapor barrier properties of soy protein films, the transparent films were prepared by blending 5 wt % soy protein isolate (SPI) alkaline water solution with 2 wt % carboxymethylated konjac glucomannan (CMKGM) aqueous solution and drying at 30 °C. The structure and properties of the blend films were studied by infrared spectroscopy, wide‐angle X‐ray diffraction spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, and measurements of mechanical properties and water vapor transmission. The results demonstrated a strong interaction and good miscibility between SPI and CMKGM due to intermolecular hydrogen bonding. The thermostability and mechanical and water vapor barrier properties of blend films were greatly enhanced due to the strong intermolecular hydrogen bonding between SPI and CMKGM. The tensile strength and breaking elongation of blend films increased with the increase of CMKGM content: the maximum values achieved were 54.6 MPa and 37%, respectively, when the CMKGM content was 70 wt %. The water vapor transmission of blend films decreased with the increase of CMKGM content: the lowest value achieved was 74.8 mg · cm^?2 · d^?1 when the CMKGM content was 70 wt %. The SPI–CMKGM blend films provide promising applications to fresh food packaging. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1095–1099, 2003     

Bismaleimides blend with a synthesised phosphorus-containing benzoxazine and its mechanical and tribological properties

ABSTRACT

The phosphorus-containing benzoxazine-bismaleimides (PBOZ-BMI) resin was fabricated by blending the synthesised phosphorus-contained benzoxazine monomer (PBOZ) with bismaleimides (BMI). The influence of PBOZ content on the mechanical and tribological properties of PBOZ-BMI resin was researched. The results showed that suitable addition of PBOZ can enhance the mechanical properties and decrease the frictional coefficient and wear rate of PBOZ-BMI resin to some extent. The improvement of mechanical properties of PBOZ-BMI can be attributed to the cross hydrogen bonding and network interpenetrating. The wear mechanism of the PBOZ-BMI resin was converted from fatigue wear to adhesive wear after the addition of PBOZ, observed from the wear surface of the materials by scanning electron microscopy (SEM). The enhancement of tribological properties is due to the high heat resistance of PBOZ, which can inhibit the adhesive wear during the wear effective.     

丁腈橡胶／氯化丁基橡胶共混物的性能研究

研究了丁腈橡胶／氯化丁基橡胶共混物的低温性能和耐热性能。结果表明．选用TMTD／CZ／ZnO作共硫化体系,共混物体系两相的相容性较好;在并用比例为70／30时,与纯NBR相比,共混物Tg下降5.5℃,失重5％热分解温度提高38.4℃,且耐油性变化很小,适宜制备高低温性能较好的耐油橡胶制品。     

CPVC/ABS二元共混物性能的研究

研究了ABS树脂对CPVC/ABS共混物的力学性能和加工性能的影响.结果表明随着ABS含量的增加,CPVC/ABS二元共混物的拉伸强度、维卡软化点和熔体粘度下降,而CPVC/ABS共混物的冲击强度得到明显改善;当ABS含量为30%时,共混物的冲击强度为11.0 kJ/m2,维卡软化点为110 ℃,凝胶化时间为52 s,平衡扭矩为17.7 N·m.     

Physical properties of silk fibroin/chitosan blend films

Silk fibroin/chitosan blend films were examined through IR spectroscopy to determine the conformational changes of silk fibroin. The effects of the fibroin/chitosan blend ratios (chitosan content) on the physical and mechanical properties were investigated to discover the feasibility of using these films as biomedical materials such as artificial skin and wound dressing. The mechanical properties of the blend films containing 10–40% chitosan were found to be excellent. The tensile strength, breaking elongation, and Young's modulus were affected by the chitosan contents of the blend films, which were also related to the density and degree of swelling. The coefficient of water vapor permeability of the blend films increased linearly with the chitosan content, and the values of 1000–2000 g m^?2 day^?1 were comparable to those of commercial wound dressings. Silk fibroin/chitosan blend films had good oxygen and water vapor permeabilities, making them useful as biomaterials. In particular, the blend film containing 40–50% chitosan showed very high oxygen permeability. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 928–934, 2001