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     

γ射线辐照对PVAL/Gel共混膜拉伸性能的影响

将明胶(Gel)按不同比例加入到聚乙烯醇(PVAL)溶液中,制备Gel质量分数分别为0%,5%,10%,15%和20%的混合溶液,混合均匀后分别浇铸到用硅纸覆盖的玻璃板上制备PVAL/Gel共混膜。研究了用不同剂量的γ射线(60Co)辐照对共混膜拉伸性能的影响,最后用傅立叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)对共混膜进行了结构表征和形貌分析。研究结果表明,用γ射线辐照时,纯PVAL膜、PVAL/Gel共混膜的拉伸强度和断裂伸长率均随着辐照剂量的增加而升高,但达到一定值后又开始下降;当辐照剂量为150 krad时,纯PVAL膜的拉伸强度达到最大值,为37 MPa;当辐照剂量为50 krad时,Gel质量分数分别为5%,10%,15%的共混膜的拉伸强度值均有极大值,分别为33,26,24 MPa。当辐照剂量为100 krad时,共混膜的断裂伸长率均有极大值,其中纯PVAL膜、Gel质量分数为10%的共混膜的断裂伸长率分别为175%,162%。FTIR和SEM分析结果表明,γ射线辐照处理后的膜发生了化学反应,形成了更多的化学键,改善了膜的拉伸性能。     

Jute Reinforced Polymer Composite by Gamma Radiation: Effect of Surface Treatment with UV Radiation

Jute (Hessian cloth) reinforced polymer composites were prepared with a mixture of 2-hydroxy ethyl methacrylate (HEMA) and aliphatic urethane diacrylate oligomer (EB-204), and then cured under gamma radiation. Thick pure polymer films (2 mm thickness) were prepared by using the same monomer and oligomer at different weight ratios, and 500 krad of total gamma radiation dose at 600 krad/hr was selected for the curing of all composites. Total radiation dose, jute content, and monomer concentration were optimized with the extent of mechanical properties. Among all resulting composites, the composite of 38% jute content at monomer:oligomer = 50:50 (w/w) ratios showed the better mechanical properties, such as 108% increase in tensile strength (TS), 58% increase in bending strength (BS), 138% increase in tensile modulus (TM), and 211% increase in bending modulus (BM) relative to pure polymer film. The gel content values were also found to increase with the increase of jute content in the composite. But the elongation at break (Eb) for both tensile and bending was found to decrease with increasing jute content. The best mechanical properties were obtained when jute fibers were pre-irradiated with UV radiation, such as 150% increase in TS, 90% increase in BS relative to polymer film, 19% increase in TS, and 15% increase in BS relative to untreated jute-based composites. A water uptake behavior investigation of the resulting composites was also performed and composites based on UV-treated jute showed the minimum water uptake value.     

Properties of starch‐based blend films using citric acid as additive. II

Starch/polyvinyl alcohol (PVA) blend films were prepared by using corn starch, polyvinyl alcohol (PVA), glycerol (GL), and citric acid (CA) as additives and glutaraldehyde (GLU) as crosslinking agent for the mixing process. The additives, drying temperature, and the influence of crosslinker of films on the properties of the films were investigated. The mechanical properties, tensile strength (TS), elongation at break (% E), degree of swelling (DS), and solubility (S) of starch/PVA blend film were examined adding GL and CA as additives. At all measurement results, except for DS, the film adding CA was better than GL because hydrogen bonding at the presence of CA with hydroxyl group and carboxyl group increased the inter/intramolecular interaction between starch, PVA, and additives. CA improves the properties of starch/PVA blend film compared with GL. TS, % E, DS, and S of film adding GLU as crosslinking agent were examined. With increasing GLU contents, TS increases but % E, DS, and S value of GL‐added and CA‐added films decrease. When the film was dried at low temperature, the physical properties of the films were clearly improved because the hydrogen bonding was activated at low temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2554–2560, 2006     

Preparation and Characterization of the Mechanical Properties of the Photocured Chitosan/Starch Blend Film

The chitosan/starch blend films of 2:1 ratio were prepared by solution casting. Tensile strength (TS) and elongation at break (%Eb) of chitosan/starch blend film were found to be 9.33 MPa and 3.6%, respectively. The blend films (2% Chitosan) were soaked in six different formulations of methylmethacrylate (MMA) monomer and aliphatic urethane diacrylate oligomer (M-1200) at different time intervals (1–5 min) and irradiated under UV radiation at different intensities (5–35 pass). Formulations containing 43% MMA and 15% oligomer in methanol solution showed 209% increase in TS at 25th UV pass for 4 min soaking time. SEM and FTIR were used to investigate the molecular interaction and morphology of the blend film, respectively.     

A comparative study of gamma and ultraviolet radiation on gelatin film with 2-ethylhexyl acrylate

Gelatin films were prepared from gelatin granules in an aqueous medium by casting. Tensile strength (TS) and elongation at break (Eb%) of the films were found to be 29.2?MPa and 4.9%, respectively. Gelatin films were irradiated under gamma and UV radiation with different doses. Gamma treated gelatin films showed higher TS and Eb% over untreated ones, and even higher than that of the UV treated films. A series of gelatin solutions (formulations) was prepared by blending varying percentages (2–10% by wt) of 2-ethylhexyl acrylate (EHA) and then the films were prepared. Some EHA-blended gelatin films were irradiated under gamma radiation at various doses (50–500?krad) and other films were cured under UV radiation at different intensities (10–30 UV passes). EHA-blended?+?gamma treated gelatin films showed the highest mechanical properties than that of the EHA-blended?+?UV treated films. The degradation properties present in the soil were determined for the pure and treated films. It was observed that EHA-blended?+?gamma treated gelatin film degrades more than that of the EHA-blended?+?UV treated films.     

Influence of forming method of blending versus casting layer-by-layer on structural properties and packing performances of casein-gelatin composite edible film under different appending proportion

In order to obtain casein edible films with great packing performance, gelatin as the reinforcing additive with different ratios were loaded via two methods including layer- by- layer and blending. A comparative study on structure properties between double layers and blending films made from casein and gelatin was obtained by scanning electron microscopy and Fourier transform infrared spectroscopy. The difference between the films' packing characters were conducted by water vapor permeability (WVP), optical property, and mechanical properties (including tensile strength (TS) and elongation (EAB)). The results showed that the degree of films roughness increased and the structural stability decreased as the increase of gelatin additive ratio in both double layers and blending films. Thickness and WVP both displayed a trend of increasing first then decreasing at the dividing of gelatin instead of casein in 50%. Importantly, WVP values in double layers film with a largest value of 6.95 gm⁻¹Pa⁻¹s⁻¹ was higher than blending films, observably (P < 0.05). Additionally, TS in blending film was increased by 23.44% than double layers film under the gelatin additive proportion of 70%, and EAB value in double layers film was larger by 207.65% than blending film under the gelatin additive proportion of 10%.     

Studies on the Mechanical Properties of Gelatin and Its Blends with Vinyltrimethoxysilane: Effect of Gamma Radiation

Gelatin films were prepared by casting. Tensile strength (TS), elongation at break (Eb) and tensile modulus (TM) of the gelatin films were found to be 56 MPa, 6.1% and 1.14 GPa, respectively. Effect of gamma radiation (Co-60) on the mechanical properties of the gelatin films was studied. Vinyltrimethoxysilane (VTMS) was added to the gelatin during casting varying 1–7% by weight and found to increase the TS and TM significantly. Then the films were irradiated and found further increase of TS and TM. Water uptake of the gelatin films and 5% VTMS containing gelatin films were also evaluated.     

Bio‐nanocomposite films based on cellulose nanocrystals filled polyvinyl alcohol/chitosan polymer blend

Bio‐nanocomposite films based on polyvinyl alcohol/chitosan (PVA/CS) polymeric blend and cellulose nanocrystals (CNC) were prepared by casting a homogenous and stable aqueous mixture of the three components. CNC used as nanoreinforcing agents were extracted at the nanometric scale from sugarcane bagasse via sulfuric acid hydrolysis; then they were characterized and successfully dispersed into a PVA/CS (50/50, w/w) blend to produce PVA/CS–CNC bio‐nanocomposite films at different CNC contents (0.5, 2.5, 5 wt %). Viscosity measurement of the film‐forming solutions and structural and morphological characterizations of the solid films showed that the CNC are well dispersed into PVA/CS blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and CNC, thus improving their properties. The obtained bio‐nanocomposite films are mechanically strong and exhibit improved thermal properties. The addition of 5 wt % CNC within a PVA/CS blend increased the Young's modulus by 105%, the tensile strength by 77%, and the toughness by 68%. Herein, the utilization of Moroccan sugarcane bagasse as raw material to produce high quality CNC has been explored. Additionally, the ability of the as‐isolated CNC to reinforce polymer blends was studied, resulting in the production of the aforementioned bio‐nanocomposite films with improved properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42004.     

A gelatin/PLA-b-PEG film of excellent gas barrier and mechanical properties

A polylactic acid-polyethylene glycol block copolymer (PLA-b-PEG) was used as an additive to prepare gelatin/PLA-b-PEG blend films for the first time. The PEG molecule block enhanced the compatibility of the PLA molecule block with gelatin, which greatly improved the excellent mechanical and gas barrier properties of the gelatin film. The film contained 5 wt% PLA-b-PEG possessed the highest tensile strength and the highest elastic modulus. When the PLA-b-PEG content further increased to 20 wt%, the tensile strength, elastic modulus and elongation at the break of the blend film were all higher than pure gelatin film, suggesting that the gelatin/PLA-b-PEG blend film was pliable and tough. The blend film possessed not only excellent oxygen barrier property, but also a much-improved water barrier property. The degradation rate of the blend film was elongated controllably by regulating the content of the PLA-b-PEG copolymer. The blend film showed great potential in the application of food packaging.     

Characterization of polyvinyl alcohol/gelatin blend hydrogel films for biomedical applications

In the present investigation, attempt was made to prepare blend hydrogel by esterification of polyvinyl alcohol with gelatin. The blend hydrogel was further converted into films by the conventional solution‐casting method. These films were characterized by FTIR, DSC, and X‐ray diffraction studies. The refractive index and viscosity of different composition of the blends were measured in the solution phase of the material. The mechanical properties of the blend films were measured by tensile test. Swelling behavior of the blend hydrogel was also studied. The FTIR spectrum of the blend film indicated complete esterification of the free carboxylic group of gelatin. The DSC results indicate that the addition of gelatin with PVA changes the thermal behavior like melting temperature of PVA, which may be due to the miscibility of PVA with gelatin. The interaction of gelatin with PVA molecule changes the crystallite parameters and the degree of crystallinity. The crystallinity of the blend film was mainly due to gelatin. The comparison of viscosity indicated an increase in the segment density within the molecular coil. The results revealed the changes observed in the properties of the gel, and it enhances the gel formation at viscoelastic phase of the material. The blend film had sufficient strength and water‐holding capacity. The results obtained indicated that the blend film could be used for various biomedical applications such as wound dressing and drug‐delivery systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Development and compatibility assessment of new composite film based on sugar beet pulp and polyvinyl alcohol intended for packaging applications

In this study, interaction and compatibility between sugar‐beet pulp (SBP) and polyvinyl alcohol (PVA) in blend films was assessed. Film‐forming dispersions of different ratios of SBP to PVA (100/0, 75/25, 50/50, and 25/75) were cast at room temperature. The effects of adding PVA to SBP on the resulting film's physical, mechanical and barrier properties and thermal stability were investigated. X‐ray diffraction and environmental scanning electron microscopy (ESEM) were used to characterize the structure and morphology of the composites. When PVA was also added to the composite films, the films became softer, less rigid and more stretchable than pure SBP films. The addition of PVA gave significantly greater elongation at break (12.45%) and lower water vapor permeability (1.55 × 10^?10 g s^?1 m^?1 Pa^?1), but tensile strength did not markedly change, remaining around 59.68 MPa. Thermogravimetric analysis also showed that SBP/PVA film had better thermal stability than SBP film. The ESEM results showed that the compatibility of SBP50/PVA50 was better than those of other composite films. These results suggest that when taking all the studied variables into account, composite films formulated with 50% PVA are most suitable for various packaging applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41354.     

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     

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,...     

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     

Improvement of Physicochemical Properties of Natural Rubber and Polyvinyl Alcohol Blends by Radiation Vulcanization

Variable compositions of natural rubber latex (NRL) and polyvinyl alcohol (PVA) have been blended. The contents of PVA in the blends were varied from 0.5 phr to 3.0 phr and the total solids contents of NRL was fixed to 50%. The blends were irradiated at different irradiation doses (0–20 kGy) in the presence of normal butylacrylate (n-BA). The permanent set; swelling ratio and elongation at break point of the blended films at all compositions decrease with the increase of radiation doses whereas increase is observed in cross-linking density, gel content, tensile strength and modulus. Sharp changes of all the properties were observed between 3–5 kGy radiation doses. On the other hand, at higher radiation doses, ≥ 5 kGy, the permanent set, swelling ratio, gel content did not show any appreciable change whereas cross-linking density, tensile strength, modulus and elongation at break point are changed. The maximum cross-linking density of blend is observed with 2.0 phr PVA at 12 kGy radiation. The highest value of modulus and tensile strength of the same blend are found at 10 kGy and 5 kGy respectively. Blends with 2.0 phr PVA for all compositions proved to be optimum for improving varies properties at 5–12 kGy radiation doses.     

Biodegradable PPC/(PVA-TPU) ternary blend blown films with enhanced mechanical properties

Biodegradable films of poly(propylene carbonate)/poly(vinyl alcohol)-thermoplastic polyurethane [PPC/(PVA-TPU)] ternary blends were successfully prepared by melting blending method. The mechanical properties of poly(propylene carbonate) blown film were greatly improved by blending PPC with PVA-TPU. In order to afford the melt processing of PVA, the PVA-TPU binary blend was firstly prepared using thermoplastic polyurethane as a polymeric plasticizer. The rheological behavior, mechanical properties and morphology of these blends were studied. Considering its melt viscosity and thermally processing temperature, the PVA-50%TPU, as a modifier, was blended with PPC to prepare PPC/(PVA-TPU) ternary blend. SEM observation revealed a basic one-phase morphological structure with very good interfacial adhesion between the extremely blurred PPC and PVA-TPU two components. Meanwhile, the miscibility of the ternary components was verified by only one glass-transition temperature obtained from DMA tests. The tensile strength and tear strength of PPC/(PVA-TPU) blown films were determined at different temperatures. The results demonstrate that the mechanical properties of PPC/(PVA-TPU) films were enhanced dramatically at low temperature when compared with neat PPC. At room temperature, PPC/30 %(PVA-50%TPU) blown film exhibited a tensile strength of 26 MPa, and an elongation at break of 484.0 %. Its tear strength in the take-up direction is 124.1 kN/m, and the one in machine direction is 141.9 kN/m. At a low temperature of 0 °C, PPC/30 %(PVA-50%TPU) exhibited a tensile strength of 40.7 MPa and tear strength of 107 kN/m, which are 153 % and 142 % of those of neat PPC respectively. The blending of PPC with the PVA plasticized with TPU provides a practical way to extend the application of the new biodegradable polymer of PPC in the area of blown films.     

Water stability of high‐molecular‐weight (HMW) syndiotacticity‐rich poly(vinyl alcohol) (PVA)/HMW atactic PVA/iodine complex blend films

To precisely identify the effect of blend ratios of syndiotacticity‐rich poly(vinyl alcohol) (s‐PVA)/atactic PVA (a‐PVA) on the water stability of s‐PVA/a‐PVA/iodine complex blend films, we prepared two PVAs with similar number‐averaged degrees of polymerization of 4000 and degrees of saponification of 99.9% and with different syndiotactic diad contents of 58.5 and 53.5%, respectively. The desorption behavior of iodine in s‐PVA/a‐PVA/iodine complex films in water was investigated in terms of the solubility of s‐PVA/a‐PVA blend films in water. The degree of solubility of s‐PVA/a‐PVA blend films with s‐PVA content over 50% in water at 70°C was limited to about 10–20%, whereas that of s‐PVA/a‐PVA blend films with s‐PVA content of 10% was 85% under the same conditions. The degree of iodine desorption of complex blend films decreased with increasing s‐PVA content. The degree of iodine desorption of s‐PVA/a‐PVA drawn film with s‐PVA content of 90% was limited to 7%, regardless of the soaking temperature from 30 to 70°C. The desorption of iodine in water was strongly affected by the dissolution of blends. Moreover, the stability of iodine in the drawn s‐PVA/a‐PVA/iodine blend films in hot water was far superior to that of the undrawn film. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1435–1439, 2004     

Antioxidant and physicochemical properties of blended films based on gelatin‐sodium caseinate activated with natural extracts

Blend films of pigskin gelatin (GEL) and sodium caseinate (SCas) with boldo (B), guarana (G), cinnamon (C), or rosemary (R) extracts added were studied. SCas and extracts addition in blend films significantly increased the gloss and better UV barrier of GEL100 films. Extracts incorporation significantly decreased the rigidity and elongation of GEL100 films, which were significantly improved in GEL75:SCas25 blend films with extracts (EM = 295.69 ± 21.75 MPa and EB = 11.60 ± 3.43%). SCas addition not affected the TS parameter. The water vapor permeability of GEL100 films was reduced in blended films with extracts, showing the lowest value for GEL75:SCas25 + R (0.99 ± 0.07 × 10¹⁰ g s^?1 m^?1 Pa^?1). FTIR and microstructure analyses showed good compatibility for all components. The antioxidant activity of GEL100 was significantly increased with SCas and extracts addition (GEL50:SCas50 + R = 4.31 ± 0.11 mM ), suggesting the application of these films as an active food packaging material. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44467.     

Phase separation in poly(vinyl alcohol)/gelatin blend systems

Blends of a commercial poly(vinyl alcohol) (a-PVA) derived from vinyl acetate and gelatin obtained from collagen were prepared by mixing aqueous solutions of both samples under various conditions. For the blend hydrogels, the depression of melting temperatures was observed at high PVA content. Similarly to the a-PVA/silk fibroin (SF) system, when the degrees of polymerization of PVA increased, the microphase separation region in a phase diagram of the blend films increased for the a-PVA/gelatin system. In the IR spectra of the blend films, no absorption bands corresponding to a conformational change of gelatin appeared. Comparison of the mechanical properties of the a-PVA/gelatin and a-PVA/SF systems, showed the interaction between PVA and gelatin molecules to be smaller than that between PVA and SF molecules. © 1999 Society of Chemical Industry