Compatibility and Properties of Biodegradable Blend Films with Gelatin and Poly(vinyl alcohol)

The blend films with gelatin and poly（vinyl alcohol） （PVA） were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-transform infrared spectroscopy （FTIR）, x-ray diffraction （XRD）, thermogravimetry analysis （TG）, and differential scanning calorimetry （DSC） were employed to characterize the resultant blend films. According to optic result, the opacity of the blend film at the ratio of 20/80 （w/w, Gel to PVA） was the lowest, indicating the best compatibility between Gel and PVA at the ratio. The results oflR, XRD, DSC, and TG revealed an intensive interaction and good compatibility between them in the blend film at the ratio. The mechanical properties and solubility showed that PVA content in the blend films obviously affected the elongation at break and solubility. The mechanical properties and water resistance of gelatin film may be improved by the introduetion of PVA.

Influence of Poly（methyl metacrylate） Addition on Resistive Switching Performance of P3HT/P（VDF-TrFE） Blend Films

Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usually deposited from solution, during which phase separation oc- curred, resulting in discrete semiconducting phase whose electrical property was modulated by surrounding ferroelectric phase. However, phase separation resulted in rough surface and thus large leakage current. To further improve electrical properties of such blend films, poly（methyl metacrylate） （PMMA） was introduced as additive into P3HT/P（VDF-TrFE） semiconducting/ferroelectric blend films in this work. It indicated that small amount of PMMA addition could effectively enhance the electrical stability to both large electrical stress and electrical fatigue and further improve retention performance. Overmuch PMMA addition tended to result in the loss of resistive switching property. A model on the configuration of three components was also put forward to well understand our experimental observations.

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2%(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

Simulation of Morphologies and Mechanical Properties of A/B Polymer Blend Film

The effects of blend composition and micro-phase structure on the mechanical behavior of A/B polymer blend film are studied by coupling the Monte Carlo(MC) simulation of morphology with the lattice spring model(LSM) of micro mechanics of materials.The MC method with bond length fluctuation and cavity diffusion algorithm on cubic lattice is adopted to simulate the micro-phase structure of A/B polymer blend.The information of morphology and structure is then inputted to the LSM composed of a three-dimensional network of springs to obtain the mechanical properties of polymer blend film.Simulated results show that the mechanical response is mainly affected by the density and the composition of polymer blend film through the morphology transition.When a force is applied on the outer boundary of polymer blend film,the vicinity of the inner cavities experiences higher stresses and strains responsible for the onset of crack propagation and the premature failure of the entire system.

PROPERTIES OF SILK FIBROIN/POLY(ETHYLENE GLYCOL)400 BLEND FILMS

The blend film of silk fibroin (SF) and poly(ethylene glycol)400 (PEG400) with a blend ratio of 2/1 (wt/wt) wasprepared simply by dropping a little PEG400 into the SF solution and then casting the mixed aqueous solution at 50℃. Theresulting film exhibited much better mechanical properties in the dry and wet state than SF itself, owing to theconformational change of SF in the blends from the random coil to the β-sheet structure and intermolecular hydrogen bondformation between SF and PEG400. Thermogravimetric analysis showed that the initial thermal decomposition temperatureof the blend film was 170℃, which was 80℃ lower than that of SF (250℃) and 20℃ higher than that of PEG400 (150℃),and indicated a Strong interaction between two components of the blend. No crystalline peaks were observed in the X-raydiffraction curve of the blend film. Cell culture test showed that SF/PEG400 was a suitable substrate for the growth of humanumbilical vein endothelial cells (HUVEC).

A study of chitosan blend film as a carrier of corneal endothelial cells

In order to evaluate the cytocompatibility and biocompatibility of a new kind of chitosan blend film as a carrier of corneal endothelial cell, rabbit corneal endothelial cells cultured in vitro were breeded onto the film. After a cell monolayer formed, the scanning electron micrography was performed. After inplanted into anterior chamber, slit lamp observation, thickness metering, specular microscopy and HE staining were performed at random time after operation to evaluate the biocompatibility. Inflmmnation in anterior, thickness of cornea, cell density, hexagonality and cell size of the surgical cornea were taken as the indexes of biocompatibility. The cultured cells exhibited a confluent monolayer 10 days after incubation, which proved the satisfactory cytocompatibility of this film. Biocompatibility assay results suggested the implantation feasibility of the film as a carder of corneal endothelial cells.

MONTE CARLO SIMULATION OF TRIBLOCK COPOLYMER/HOMOPOLYMER BLEND FILMS

The morphologies of triblock copolymer/homopolymer blend films, ABA/A and ABAIB, confined between two neutral hard walls were studied via Monte Carlo （MC） simulation on a simple .cubic lattice. The effects of φh （the volume fraction of homopolymer） and Md/Mb （the molecular weight of homopolymer in relation to that of the corresponding blocks in the copolymer） on the morphologies were investigated in detail.

Influence of Phase Behavior and Miscibility on Mechanical, Thermal and Micro-Structure of Soluble Starch-Gelatin Thermoplastic Biodegradable Blend Films

Polymer blends of cold water soluble starches (amylose or amylopectin soluble starch) with gelatin were prepared using solvent casting method. The solid state miscibility and polymer-polymer interactions between the constituent polymers were studied by fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorirmetry (DSC), light optical microscopy (OP) and scanning electron microscopy (SEM), whereas the thermal stability of the blends was studied by thermogravimetric analysis (TGA). Furthermore, tensile and water vapor barrier properties of the blends were assessed. The obtained results exhibited that gelatin was more miscible with amylose soluble starch than with amylopectin soluble starch. Moreover, enhancing mechanical and water barrier properties of amylose soluble starch/gelatin blends were more pronounced than those of amylopectin soluble starch/gelatin blends. Generally, tensile strength (TS) and Elongation percentage (E) of the blend films were found to be gradually increased with increasing the proportion of gelatin. Nevertheless, increasing starch proportion was in favor of decreasing water vapor permeability (WVP). At equal proportions of starch and gelatin (1:1), TS was raised up to 8.69 MPa for amylose soluble starch/gelatin blend films while it raised up to 4.96 MPa for amylopectin soluble starch/gelatin blend films, and so on E was increased to its maximum by ~179.6% for soluble amylose starch/gelatin blends while it was increased to ~114.5% for amylopectin soluble starch/gelatin blends. On the other hand, WVP was significantly decreased to be 6.46 and 12.09 g·mm/m2·day·kPa for blends of amylose and amylopectin soluble?starches, respectively.

Reactive processing of poly(lactic acid)/poly(ethylene octene) blend film with tailored interfacial intermolecular entanglement and toughening mechanism

In order to obtain a uniform and effectively toughened poly(lactic acid)film by blending with low content of poly(ethylene octene)(POE)with high elasticity,the tailored interfacial intermolecular interaction and entanglement between the two phases of the PLA/POE blend was innovatively constructed via the facile reactive melt blending process through the reaction of the epoxy/anhydride groups grafted on the POE chains with the end groups of PLA chains(PLA/GPOE-MPOE).It was observed that POE domains were embedded tightly in PLA matrix with a fuzzy interface and abundant interface transition area,and the impact fractured surface of the blend showed an obvious plastic deformation with less occurrence of fibrillation of PLA matrix or interfacial de-bonding.Compared with neat PLA and directly blended PLA/POE blends,the PLA/GPOE-MPOE blend exhibited much higher complex viscosity/storage modulus,much lower tanδvalues in the terminal region,and obvious strain-hardening behavior.The deviation in viscoelastic behavior of PLA/GPOE-MPOE from linear PLA indicated the enhanced molecular entanglement between the long-branched chains,resulting in an enhancement of the stretching ability during biaxial drawing of the blend.Uniform PLA/GPOE-MPOE films with draw ratio as high as 7×7 were obtained through biaxial stretching,which showed much higher tensile strength and the elongation at break than that of neat PLA and PLA/POE film.This work provides a facile method for fabricating toughening PLA films with application potentials.

Mechanical behavior and wrinkling patterns of phaseseparated binary polymer blend film

The wrinkling of phase-separated binary polymer blend film was studied through combining the Monte Carlo(MC)simulation for morphologies with the lattice spring model(LSM)for mechanical properties.The information of morphology and structure obtained by use of MC simulation is input to the LSM composed of a three-dimensional network of springs,which allows us to determine the wrinkling and the mechanical properties of polymer blend film,such as strain,stress,and Young’s modulus.The simulated results show that the wrinkling of phase-separated binary polymer blend film is related not only to the structure of morphology,but also to the disparity in elastic moduli between polymers of blend.Our simulation results provide fundamental insight into the relationship between morphology,wrinkling,and mechanical properties for phase-separated polymer blend films and can yield guidelines for formulating blends with the desired mechanical behavior.The wrinkling results also reveal that the stretching of the phase-separated film can form the micro-template,which has a wide application prospect.

Synergistic Effect of Nucleation and Compatibilization on the Polylactide and Poly(butylene adipate-co-terephthalate) Blend Films

Polylactide （PLA） films blended with 10 wt% poly（butylene adipate-co-terephthalate） （PBAT） were prepared by using a twin screw extruder in the presence of the nucleating agent of titanium dioxide （TiO2） and the compatibilizers of toluene diisocyanate （TDI） and PLA-grafted-maleic anhydride （PLA-g-MA）. The synergistic effect of the nucleation and compatibilization on the properties and crystallization behavior of the PLA/PBAT （PLB） films was explored. The results showed that the addition of TiO2 significantly enhanced the tensile strength and the impact tensile resistance of the PLB films while slightly decreased its thermal stability. In addition, the compatibilizers of TDI and PLA-g-MA in the system not only affected the crystallinity and cold crystallization process of the PLB films, but also increased the mechanical properties of them due to the improvement of the interracial interaction between PLA and PBAT revealed by the morphological measurement. The synergistic effects of the nucleating agent and the compatibilizer afforded the blend films with increased tensile strength and impact tensile toughness, improved cold crystallization property and Xc.

MISCIBILITY AND MORPHOLOGY OF THIN FILMS OF BLENDS OF POLYSTYRENE WITH BROMINATED POLYSTYRENES: EFFECTS OF VARYING THE MOLECULAR WEIGHT, BROMINATION DEGREE AND ANNEALING

Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poly（styrene-co-p-bromo-styrene）, i.e., PS/PBrxS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised. In this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy （XPS） and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy （AFM）. In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, Mw, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.

Preparation and Characterization of Subsurface Silver Particulate Films on Polymer Blends of Polystyrene/Poly(2-vinylpyridine)/Poly(vinylpyrollidone)/Poly(4-vinylpyridine)

Silver particulate thin films on softened polymer blends of Polystyrene (PS)/Poly(2-vinyl pyridine) (P2VP), PS/Poly(4-vinylpyridine) (P4VP), and Poly(vinylpyrollidone) (PVP)/P4VP at a rate of 0.4 nm/s held at a temperature of 457 K in vacuum of 8 × 10-6 Torr by evaporation are deposited. These silver films were characterized by their electrical behavior, optical properties and Scanning electron microscopy (SEM). Silver films deposited on softened PS, and PVP give rise to a very high room temperature resistance approaching that of the substrate resistance due to the formation of a highly agglomerated structure. On the other hand, silver films on softened P2VP and P4VP give rise to a room temperature resistance in the range of tens to a few hundred MΩ/ which is desirable for device applications. Silver films on the composites of PS/P2VP, PS/P4VP and PVP/P4VP show resistances at room temperature. The optical and plasmonic response of Ag nanoparticles onto thin layers of blends shows encapsulation of nanoparticles. The electrical properties and SEM of silver nanoparticles on the thin layers of polymer blends indicate the formation of much smaller, narrower dispersion and wide size distribution.

Investigation on Mechanical Properties of CMSLDS/Acrylate Copolymeric Blending Films for Warp Sizing

Carboxymethyl starch with lower degree of substitution was, blended with acrylate copolymer for revealing the relation between mechanical properties and chemical structure of blending film. Effects of carboxymethylation of starch, acrylate constituent units of acrylate copolymers, and copolymer content of the film on the properties were investigated. The mechanical properties were evaluated in terms of tensile strength, breaking elongation, abrasion resistance, and flex-fatigue resistance. Film morphology was examined with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and atomic force microscope （AFM）. It was found that the properties depended on the degree of substitution of carboxymethyl starch, chemical structure of acrylate units, and content of acrylate copolymer. Phase-separation of the two ingredients occurred within film matrix and the separation was decreased after starch carboxymethylation. Breaking elongation and flex-fatigue resistance of the film reached maximmns when acrylate copolymer content was 50%. Excessively increasing the content of acrylate copolymer reduced the film properties.

An Investigation on Properties of PU/PVC Blended Porous Films

Structure and properties of PU/PVC blended film are fnvestlgated in the work. The experimental results show that the PU/PVC blended film has a multiplex poroslty strueture, and their structure and properties vary with PVC content in the blended film. The correlation and regresslon between the properties and PVC content are listed in the paper.

聚丙烯腈对聚乙烯醇膜形貌和性能的改进

通过流延成膜的方法制备了聚乙烯醇/聚丙烯腈共混薄膜。通过扫描电镜分析了共混膜的形貌。通过差式扫描量热仪、热重分析、拉伸测试、表面接触角测试研究了共混膜的热力学性能、机械性能和化学性能。测试结果显示聚丙烯腈对聚乙烯醇膜的形貌和性能产生了显著的影响。

木质素基水性聚氨酯/聚乙烯醇共混膜制备及性能

环境友好型薄膜代替传统石油基薄膜用于农用地膜等领域愈发引起广泛的关注和研究。薄膜性能的提高仍然是当下所要攻克的难题。针对解决传统聚乙烯醇(polyvinyl alcohol,PVA)在薄膜领域力学强度低,耐水性及隔绝紫外能力差的缺点,同时为了能够更好的提高生物质资源的使用价值,该研究以聚乙烯醇(PVA)为原料,木质素(Lignin)、水性聚氨酯(waterborne polyurethane,WBPU)作为填料剂,对木质素进行液化制备木质素液化物L(D),采用溶液浇筑法成功制备木质素基水性聚氨酯/聚乙烯醇共混膜。通过对共混膜的光学性能,形貌特征,化学结构和晶体结构进行表征分析,探究了木质素用量,L(D)/WBPU质量比对共混膜的影响。结果表明,L(D)与WBPU均能与PVA充分混合,并在含有15%L(D)的共混膜中表现出的力学性能和耐水性能最好,拉伸强度提升了10%,耐水性提高了32%,同时加强了膜的抗紫外能力,在400 nm紫外区的透光率从81.44%降低至7.69%;在不同L(D)/WBPU质量比的作用下,膜的耐水性和抗紫外性都得到进一步的加强,耐水性最高提升了68%,400 nm紫外区的透光率接近于0。该研究制备的共混膜具备较高的应用潜力,同时对食品、医药包装等领域有一定的参考意义。

无铬鞣废革屑胶原提取物与PBAT共混成膜性能

利用稀酸法分别从沸石、TWS鞣废革屑中提取胶原,以提取率、特性粘数等为指标优化提取工艺,对纯化后的胶原水解物进行表征。随后选取TWS鞣废革屑提取的胶原水解物(C-TWS)与聚己二酸对苯二甲酸丁二醇酯(PBAT)共混成膜,探究二者的成膜性能。结果表明:两种胶原水解物均含有17种氨基酸,元素组成以C、N、O为主,矿物盐含量低,是优质的生物可降解蛋白基材。PBAT/C-TWS共混过程为简单的物理共混,C-TWS组分含量的增大使复合膜的水蒸气透过量提高43.05%~182.5%。C-TWS组分含量为30%时,薄膜的最大热降解温度由405.4℃降低至386.5℃,所有比例共混膜都具有良好的透光率,共混体系中C-TWS组分含量小于50%时具有较好的相容性。

共沉淀法制备纤维素/天然橡胶薄膜及其性能研究

天然橡胶(NR)是一种重要的战略资源,但是其本身力学性能可能无法完全满足应用需求,往往需要使用补强剂对其进行改性。而传统的橡胶工艺严重依赖以石油为基础的材料,如炭黑(CB),对环境污染严重,不利于浅色制品的应用。为响应绿色环保的主题,减轻环境污染,选取绿色可再生的纤维素作为浅色橡胶制品的补强剂是一个应用前景广阔的技术方案。纤维素与天然橡胶的相容性决定了改性材料的性能。本研究使用羟乙基纤维素(HEC)、羧甲基纤维素钠(CMC)和纳米纤维素(CNF)为原料,对天然橡胶薄膜进行改性,旨在显著提升其综合性能。通过对复合薄膜材料进行FT-IR、XPS、力学性能、交联密度、硬度、接触角等表征测试,研究结果表明,这三种纤维素均可以提高天然橡胶的交联密度,HEC对天然橡胶的交联密度提升最大,可达到3.33倍。此外,纤维素与天然橡胶之间形成的氢键连接,对天然橡胶薄膜的力学性能起到了关键作用。HEC/NR复合薄膜的拉伸强度最大,达到36.17 MPa,断裂伸长率达2138.78%。纤维素的加入显著提高了复合薄膜的亲水性,这主要归功于纤维素分子中丰富的羟基。这一发现为改善天然橡胶制品的润湿性和加工性提供了新思路,也为复合薄膜材料在多个领域的应用开辟新的可能性。

PA 6/PA 612共混双向拉伸膜的制备及结晶行为研究

以质量比8020的尼龙6(PA 6)和尼龙612(PA 612)共混制备PA 6/612流延膜,再经纵向和横向拉伸制得PA 6/612双向拉伸膜,考察共混膜的力学性能、熔融结晶行为、微观形貌、结晶结构,并采用Jeriorny修正的Avrami方程、Ozama方程及莫志深方法分析共混膜的非等温结晶动力学。结果表明:PA 6/612双向拉伸膜的纵向、横向抗拉强度分别为249,244 MPa,透光率为92%,雾度为5%,表现出优异的透明性和力学性能;PA 6/612流延膜的结晶温度和起始结晶温度分别为182.2℃和188.1℃,相对于纯PA 6和纯PA 612向低温方向移动,结晶能力降低;PA 6/612流延膜等温结晶过程的晶体为条带状,无黑十字消光图案,晶体尺寸较PA 6、PA 612流延膜小;PA 6/612流延膜以结构不稳定的β晶为主,含有少量α晶和γ晶,有利于双向拉伸;PA 6/612流延膜的Ozama指数在3.5~4.4,表现为三维球状生长的均相成核机理。