Preparation and characterization of poly(vinyl alcohol) and gelatin blend films

Poly(vinyl alcohol) (PVA) is a water-soluble polymer that has been studied intensively because of several interesting physical properties that are useful in technical applications, including biochemical and medical applications. In this article, we report the effects of the addition of gelatin on the optical, microstructural, thermal, and electrical properties of PVA. Pure and PVA/gelatin blend films were prepared with the solution-casting method. These films were further investigated with Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, and dielectric measurements. The FTIR spectrum shows a strong chemical interaction between PVA and gelatin molecules with the formation of new peaks. These peaks are due to the presence of gelatin in the blend films. The DSC results indicate that the addition of gelatin to PVA changes the thermal behavior, such as the melting temperature of PVA, and this shows that the blends are compatible with each other. This also shows that the interaction of gelatin and PVA molecules changes the crystallite parameters and the degree of crystallinity, and this supports the XRD results. The UV–vis optical study also reflects the formation of the complex and its effect on the microstructure of the blend film. Moreover, the addition of gelatin also gives rise to changes in the electrical properties of PVA/gelatin blend films. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Deduction of a facile method to construct Antheraea mylitta silk fibroin/gelatin blend films for prospective biomedical applications

Blend films of two types (I and II) were prepared by mixing Antheraea mylitta silk fibroin (AMF) and gelatin solution in various blend ratios via the solution casting method. Two different crosslinkers, namely glutaraldehyde and genipin, were used during blend preparation. The structural characteristics and thermal properties of the blend films were examined by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), Thermogravimetric analysis (TGA) and Diffrential scanning calorimetery (DSC). The FTIR spectra showed conformational alterations in type I blend films while type II films attained high β‐sheet crystallinity. The XRD diffractograms presented a high degree of crystallinity in type II blend films compared to type I, which showed an almost amorphous structure. Further, thermal and biological studies were conducted on type II films. According to the TGA thermograms, the degradation temperature of the crosslinked blend films shifted compared to pure gelatin and pure AMF films. Partial miscibility of the two components was indicated by DSC thermograms of the blends. The high water uptake capacity of type II blend films was found to imitate hydrogel behaviour. The blend films did not show any toxicity in 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay and supported L929 fibroblast cell spreading and proliferation. The biodegradation of the blend films was significantly faster than the pure silk film. © 2020 Society of Industrial Chemistry     

木质素磺酸钠与PVA共混薄膜的制备与表征

以木质素磺酸钠(LS)和聚乙烯醇(PVA)为主要原料,添加适量硼砂、明胶在水溶液中溶解共混,流延成膜.通过单因素和正交实验优选了LS/PVA共混膜制备的条件,对共混膜进行了耐水性、形貌、红外、热重、X射线衍射及差示扫描量热分析.结果表明:影响共混膜性能的主要因素有LS含量、硼砂含量以及反应时间,当硼砂含量为2.0%时,...     

Studies of chitosan. I. Preparation and characterization of chitosan/poly(vinyl alcohol) blend films

Various blending ratios of chitosan/poly (vinyl alcohol) (CS/PVA) blend films were prepared by solution blend method in this study. The thermal properties and chemical structure characterization of the CS/PVA blend films were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and Fourier transform infrared (FTIR). Based upon the observation on the DSC thermal analysis, the melting point of PVA is decreased when the amount of CS in the blend film is increased. The FTIR absorption characteristic is changed when the amount of CS in the blend film is varied. Results of X‐ray diffraction (XRD) analysis indicate that the intensity of diffraction peak at 19° of PVA becomes lower and broader with increasing the amount of CS in the CS/PVA blend film. This trend illustrates that the existence of CS decreases the crystallinity of PVA. Although both PVA and CS are hydrophilic biodegradable polymers, the results of water contact angle measurement are still shown as high as 68° and 83° for PVA and for CS films, respectively. A minimum water contact angle (56°) was observed when the blend film contains 50 wt % CS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

壳聚糖/聚乙烯醇共混膜的氢键和相容性

采用溶液共混法制备了不同配比的壳聚糖/聚乙烯醇共混膜,通过变温FTIR、TG、DTA、DSC及XRD等对共混膜的结构、氢键相互作用、热行为和结晶性等进行研究。实验结果表明,共混膜中壳聚糖与聚乙烯醇间存在强烈的氢键相互作用。氢键的存在使壳聚糖的热稳定性提高,聚乙烯醇结晶性下降,促进壳聚糖与聚乙烯醇相容。当壳聚糖/聚乙烯醇共混膜的质量比分别为10/0、7/3、5/5、3/7和0/10时,共混膜的初始分解温度分别为244 ℃、257 ℃、260 ℃、262 ℃和285 ℃。聚乙烯醇熔融温度从193 ℃下降到173 ℃,玻璃化转变温度从74.2 ℃上升至80 ℃,结晶度Xc从3.57%下降到1.97%。     

Enhanced compatibilization and orientation of polyvinyl alcohol/gelatin composite fibers using carbon nanotubes

Polyvinyl alcohol (PVA)/gelatin composite fibers containing carbon nanotubes (CNTs) had been prepared by wet‐spinning method. A remarkable increase of tensile strength of the PVA/gelatin fibers was achieved by adding small amount of CNT. The mechanism of reinforcement has been studied using a combination of differential scanning calorimetry (DSC), 2D wide‐angle X‐ray diffraction (2D‐WAXD) and scanning electron microscopy (SEM). SEM showed a decreased gelatin domain size by adding CNTs, suggesting a possible compatibilization effect between PVA and gelatin. On the other hand, an increased crystallinity and degree of orientation of PVA/gelatin fibers has been observed by adding CNTs. Thus, the increased compatibilization, crystallinity and degree of orientation in PVA/gelatin/CNTs composite fibers should be the reasons for the observed increase of mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and characterization of polyethylene oxide (PEO)/gelatin blend for biomedical application: Effect of gamma radiation

polyethylene oxide (PEO)/gelatin blend membranes of four different compositions (w/w) (5/95, 10/90, 20/80, and 30/70) were prepared by solution casting. The films were irradiated by gamma radiation at a total dose of 250 krad (dose rate of 321 krad/h). The X‐ray diffractograms demonstrate both the PEO and radiation influences on the blend thus enhancing crystallinity of gelatin. X‐ray diffractograms of irradiated blend films containing 30% PEO showed highest integrated intensity. The DTA and TGA study showed that the irradiated blend films are more thermally stable than the non‐irradiated films. TMA study showed that the incorporation of PEO into gelatin increased melting point of the blend films. The melting point for irradiated gelatin film changes from 52.9°C to 75.6°C and the glass point changes from 60.3°C to 90.6°C. The phase separation and compatibility of the PEO/gelatin blend films were studied by scanning electron microscopy (SEM). The experimental results showed that the blend films exhibit higher thermal stability and improved mechanical properties in dry state, which suggests the occurrence of interaction detected by XRD and DTA among gelatin, PEO, and water molecules in the films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of films based on crosslinked blends of gum acacia,polyvinylalcohol, and polyvinylpyrrolidone-iodine complex

In an attempt to develop iodine-release systems based on polymeric blend for biomedical applications, our research group prepared blends of gum acacia (GA), polyvinylalcohol (PVA), and polyvinylpyrrolidone-iodine (PVP-I) complex. The blends of GA/PVA and GA/PVA/PVP-I prepared from the aqueous solutions of the polymers were crosslinked with glutaraldehyde to increase the water resistance of the films and to improve their thermal and mechanical properties. The crosslinked GA/PVA and GA/PVA/PVP-I blend films were characterized by FTIR spectroscopy, DSC, and TGA. The swelling behavior of the prepared blends was investigated and crosslinked GA/PVA blend films were found to be pH sensitive. The properties of PVP-I containing blends differed from those prepared without it probably due to the formation of an intermolecular interaction between PVP-I and the hydroxy-polymers. The results indicated that after crosslinking the blends showed improvement in water resistance, thermal, and mechanical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Enhanced oxygen‐barrier and water‐resistance properties of poly(vinyl alcohol) blended with poly(acrylic acid) for packaging applications

To enhance the oxygen‐barrier and water‐resistance properties of poly(vinyl alcohol) (PVA) and expand its food packaging applicability, five crosslinked poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) blend films were prepared via esterification reactions between hydroxyl groups in PVA and carboxylic acid groups in PAA. The physical characteristics of the blends, including the thermal, barrier, mechanical and optical properties, were investigated as a function of PAA ratio. With increasing PAA content, the crosslinking density was significantly increased, resulting in changes in the chemical structure, morphology and crystallinity of the films. The oxygen transmission rate of pure PVA decreased from 5.91 to 1.59 cc m^?1 day^?1 with increasing PAA ratio. The water resistance, too, increased remarkably. All the blend films showed good optical transparency. The physical properties of the blend films were strongly correlated with the chemical structure and morphology changes, which varied with the PAA content. © 2016 Society of Chemical Industry     

Poly (vinyl alcohol)/polylactic acid blend film with enhanced processability,compatibility, and mechanical property fabricated via melt processing

Poly (vinyl alcohol)/polylactic acid (PVA/PLA) blend film, which is environment friendly and has potential applications in food and electronic packaging fields, was fabricated by melt extrusion casting. Fourier transform infrared spectroscopy analysis confirmed the formation of the hydrogen bonding between PLA and PVA, which improved the compatibility of PLA with PVA, making PLA uniformly dispersed in PVA matrix as small spheres, even when PLA content increase to 15 wt%. In this way, the original hydrogen bond network among PVA was disturbed and the chain mobility of PVA was activated, endowing PVA/PLA blends with lower melt viscosity than bot modified PVA and PLA, and the blend films with the increased crystallinity, mechanical property, and water resistance. Compared with PVA film, the crystallinity, tensile strength and Young's modulus of the blend film with 15 wt% PLA, respectively, increased by 15.1%, 9 and 51 MPa, and the water contact angle enlarged from 23° to 60°.     

Physically crosslinked polyvinyl alcohol/chitosan/gum tragacanth hydrogels loaded with vitamin E for wound healing applications

For the healing process, in this study, an innovative polymeric hydrogel network including polyvinyl alcohol (PVA)/chitosan (CS)/gum tragacanth (GT) loaded with vitamin E (VE) was produced by the freeze–thaw approach. In order to investigate the characteristics of the prepared samples, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyzes were performed. Also, water vapor transmission rate (WVTR), swelling ratio, gel fraction and mechanical properties were measured. Then, to observe their cytocompatibility, MTT assay and cell adhesion studies were assessed. The results of FTIR confirmed the presence of PVA, CS, GT, and VE in hydrogel films. As well as, the SEM images showed the effect of the freezing and thawing method in creating a smooth surface with small and regular pores. It was found with adding the CS and GT to PVA improves swelling ratio, gel fraction, WVTR and elongation of hydrogel films. Further, in examining the adhesion and cytotoxicity of the samples, the non-toxic quiddity of the PVA/CS/GT hydrogel films was corroborated. In the end, the antibacterial properties revealed that the film containing GT and CS had the greatest antibacterial activity. According to the observed results, PVA/CS/GT hydrogel films loaded with VE can be good for wound healing applications.     

季铵醚化-辛烯基琥珀酸酯化淀粉与PVA共混膜力学性能研究

为克服淀粉膜脆且硬的缺陷,制备季铵醚化-辛烯基琥珀酸酯化淀粉（QAS）,并将它与聚乙烯醇（PVA）进行混合来制备共混膜;用X射线衍射仪进行共混膜结晶度测定,用扫描电子显微镜观察共混膜的表面形貌,研究QAS/PVA共混比和PVA结构对共混膜力学性能的影响。结果表明,QAS/PVA共混膜的结晶度比QAS膜的结晶度有所降低;随着QAS含量的增加,共混膜的断裂伸长率逐渐减小,断裂强度先减小后增大,当QAS/PVA共混比为50/50（质量比,下同）时,断裂强度达到最小值;随着PVA聚合度和醇解度的增加,共混膜的断裂强度和断裂伸长率也随之增大。     

Nanostructured PZT synthesized from metal–polyvinyl alcohol gel: Studies on metal–polymer interaction

PbZr_0.53Ti_0.47O₃ (PZT) nanoparticles of size distribution ～1–6 nm were synthesized by single‐step autoignition of metal–polyvinyl alcohol (PVA) gel. The physical and chemical bonding between the metals ions and PVA in gel was analyzed from the results of the characterization by FTIR, SEM, and XRD techniques. The appearance of a doublet band between 3500 and 3200 cm^?1 and the shifting of stretching frequency of O? H band in the FTIR spectra of gel indicated strong electrostatic interaction between the metal ions and the polar OH groups of the polymer. The electrostatic interaction decreased the extent of hydrogen bonding drastically due to engagement of polar OH groups in complex formation with the metal ions. Microstructural study of the dried gel by SEM coupled with its FTIR analyses indicated crosslinking in the metal–polymer gel. The loss of crystallinity of PVA in gel detected by XRD also indicated the drastic degradation of hydrogen bonding in PVA due to the formation of coordination complex with the metal ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of Syzygium cumini leaves extract on morphological,thermal, mechanical,and antimicrobial properties of PVA and PVA/chitosan blend films

In the present work, poly(vinyl alcohol)/Syzygium cumini leaves extract (PSN) and poly(vinyl alcohol)/chitosan/S. cumini leaves extract blend films were prepared by solution casting technique. The films were characterized by using scanning electron microscopy, atomic force microscopy, X‐ray diffraction study, Fourier transform infrared spectroscopy, thermogravimetric analysis, and universal testing machine. The results indicated that the appreciable physical interaction at lower concentrations of S. cumini leaves extract in the PVA and PVA/chitosan films contribute to the smooth uniform morphology, increased the degree of crystallinity, degradation temperature, and improved mechanical properties. Further, films were analyzed with water contact angle analyzer which illustrates that blend films were hydrophilic (PSN‐1) and hydrophobic (PCS‐1) in nature. However, blend films were also subjected to the antimicrobial study, which revealed that inclusion of S. cumini leaves extracts significantly enhanced the antibacterial activity in the PVA and PVA/chitosan film. With all of these results, fabricated blends can find potential applications in packaging material to extend the shelf life of foodstuffs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46188.     

Preparation and characterization of conductive poly(vinyl alcohol)/polyaniline doped by dodecyl benzene sulfonic acid (PVA/PANDB) blend films

In this study a solution‐blend method is adopted to prepare conductive poly(vinyl alcohol)/polyaniline doped by dodecyl benzene sulfonic acid (PVA/PANDB) blend films. Emeraldine base (EB)‐type polyaniline (PANI) is dissolved in N‐methyl‐2‐pyrrolidinone (NMP) and then blended with PVA/dodecyl benzene sulfonic acid (DBSA) solution by various amounts. It is found that the electrical conductivity and the thermal degradation onset temperature of the PVA/PANDB blend film are increased as the amount of EB‐type PANI solution is increased. Fourier transform infrared (FTIR) spectra show that the intensity of the characteristic peak of the functional groups in the blend film is significantly changed as the amount of EB‐type PANI is changed. From optical microscopy examination, it indicates that the amount and size of green particles are increased with increasing the amount of EB‐type PANI solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3415–3422, 2007     

Properties of soy protein isolate/poly(vinyl alcohol) blend “green” films: Compatibility,mechanical properties,and thermal stability

Blend films from nature soy protein isolates (SPI) and synthetical poly(vinyl alcohol) (PVA) compatibilized by glycerol were successfully fabricated by a solution‐casting method in this study. Properties of compatibility, mechanical properties, and thermal stability of SPI/PVA films were investigated based on the effect of the PVA concentration. XRD tests confirm that the SPI/PVA films were partially crystalline materials with peaks of 2θ = 20°. And, the addition of glycerol will insert the crystalline structure and destroy the blend microstructure of SPI/PVA. Differential scanning calorimetry (DSC) tests show that SPI/PVA blend polymers have a single glass transition temperature (T_g) between 80 and 115.0°C, which indicate that SPI and PVA have good compatibility. The tension tests show that SPI/PVA films exhibit both higher tensile strength (σ_b) and percentage elongation at break point (P.E.B.). Thermogravimetric analysis (TGA) and water solubility tests show that SPI/PVA blend polymer has more stable stability than pure SPI. All the results reflect that SPI/PVA/glycerol blend film provides a convenient and promising way to prepare soy protein plastics for practical application. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and swelling properties of semi‐IPN hydrogels based on chitosan‐g‐poly(acrylic acid) and phosphorylated polyvinyl alcohol

The phosphorylated poly(vinyl alcohol) (P‐PVA) samples with various substitution degrees were prepared through the esterification reaction of PVA and phosphoric acid. By using chitosan (CTS), acrylic acid (AA) and P‐PVA as raw materials, ammonium persulphate (APS) as an initiator and N,N‐methylenebisacrylamide as a crosslinker, the CTS‐g‐PAA/P‐PVA semi‐interpenetrated polymer network (IPN) ssuperabsorbent hydrogel was prepared in aqueous solution by the graft copolymerization of CTS and AA and followed by an interpenetrating and crosslinking of P‐PVA chains. The hydrogel was characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) techniques, and the influence of reaction variables, such as the substitution degree and content of P‐PVA on water absorbency were also investigated. FTIR and DSC results confirmed that PAA had been grafted onto CTS backbone and revealed the existence of phase separation and the formation of semi‐IPN network structure. SEM observations indicate that the incorporation of P‐PVA induced highly porous structure, and P‐PVA was uniformly dispersed in the polymeric network. Swelling results showed that CTS‐g‐PAA/P‐PVA semi‐IPN superabsorbent hydrogel exhibited improved swelling capability (421 g·g^?1 in distilled water and 55 g·g^?1 in 0.9 wt % NaCl solution) and swelling rate compared with CTS‐g‐PAA/PVA hydrogel (301 g·g^?1 in distilled water and 47 g·g^?1 in 0.9 wt % NaCl solution) due to the phosphorylation of PVA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of nanostructured and high transparent hydrogel films with pH sensitivity and application

Novel nanostructured, high transparent, and pH sensitive poly(2‐hydroxyethyl methacrylate‐co‐methacryliac acid)/poly(vinyl alcohol) (P(HEMA‐co‐MA)/PVA) interpenetrating polymer network (IPN) hydrogel films were prepared by precipitation copolymerization of aqueous phase and sequential IPN technology. The first P(HEMA‐co‐MA) network was synthesized in aqueous solution of PVA, then followed by aldol condensation reaction, it formed multiple IPN nanostructured hydrogel film. The film samples were characterized by IR, SEM, DSC, and UV‐vis spectrum. The transmittance arrived at 93%. Swelling and deswelling behaviors showed the multiple IPN nanostuctured film had rapid response. The mechanical properties of all the IPN films improved than that of PVA film. Using crystal violet as a model drug, the release behaviors of the films were studied. The results showed that compared with PVA, which had low drug loading and exhibited high and burst release, the three IPN films had high drug loading and exhibited sustained release. Besides, the release followed different release mechanism at pH = 4.0 and pH = 7.4, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of a novel gelatin–poly(vinyl alcohol) hydrogel film loaded with Zataria multiflora essential oil for antibacterial–antioxidant wound‐dressing applications

This study was performed to evaluate the properties of poly(vinyl alcohol) (PVA), gelatin, and PVA–gelatin dispersions and films enriched with Zataria multiflora essential oil (ZO). The results reveal that the ζ potential, particle size, and viscosity values and the antioxidant and antibacterial activities of the dispersions changed significantly with the addition of ZO to the polymer matrix. Changes in the properties of the dispersions suggested the presence of interactions between PVA or gelatin and ZO. Such interactions could affect the mechanical and water‐barrier properties of the films. ZO induced remarkable decreases in the tensile strength, elastic modulus, and swelling and increases in the elongation at break, solubility, and water‐vapor permeability of the films. Scanning electron microscopy analyses proved the impact of ZO on the film morphology, which affected the film properties, including the mechanical and water‐barrier properties. The addition of ZO to the polymer led to a coarse film microstructure because of the hydrophobic ZO aggregates, which produced discontinuities in the film matrix. ZO considerably increased the antioxidant and antibacterial activities of the dispersions. Pseudomonas aeruginosa was the most resistant bacteria. The improved antioxidant and antimicrobial activities of the PVA–ZO and gelatin–ZO indicated that such products could effectively be used as wound dressings. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45351.     

Preparation and Characterization of Gelatin-Based PVA Film: Effect of Gamma Irradiation

Gelatin-based polyvinyl alcohol (PVA) films were prepared (using a casting process) by mixing aqueous solutions of gelatin and PVA in different ratios. Monomer 1, 4-butanediol diacrylate (BDDA) was dissolved in methanol. Films containing 95% gelatin + 5% PVA were soaked in 3% BDDA monomer (w/w). These films were then irradiated under gamma radiation (⁶⁰Co) at different doses (50–500 krad) at a dose rate of 350 krad/h. The physico-mechanical and thermal properties of these films were evaluated. It was evident that 5% PVA-containing gelatin blend film exhibited the highest tensile strength (TS) value at 50 krad (51 MPa), which was 46% higher than that of non-irradiated blend films. It was also found that incorporation of PVA significantly reduced the TS value of the blend films compared to the raw film, whereas elongation at break (Eb) value was increased. A significant improvement of the blend films was also confirmed by thermogravimetric analysis (TGA) and thermo-mechanical analysis (TMA) when the acrylate group (from BDDA) was introduced into the film.