Effects of co‐plasticization of acetyl tributyl citrate and glycerol on the properties of starch/PVA films

Starch/polyvinyl alcohol (PVA) nanocomposite films by film blowing process were successfully obtained. Starch (1700 g), PVA (300 g), and organically modified montmorillonite (OMMT, 200 g) were blended and plasticized with acetyl tributyl citrate (ATBC) and glycerol (GLY) at weight ratios of 0/100, 5/95, 10/90, 15/85, 20/80, and 25/75. The structural, morphology, barrier, mechanical, and thermal properties of the films, as well as molecular interactions in the nanocomposites were analyzed. The 3.98 nm d‐spacing was the highest in starch/PVA nanocomposite films plasticized with ATBC/GLY ratio of 10/90. The film with ATBC/GLY (5/95) had the lowest WVP (3.01 × 10^?10 g m^?1 s^?1 Pa^?1). The longitudinal tensile strength (TS) of starch/PVA nanocomposite films gradually increased from 4.46 to 6.81 MPa with the increase of ATBC/GLY ratios. The T_g steadily increased from 49.2°C to 55.2°C and the ΔH of the nanocomposite films decreased from 81.77 to 51.43 J/g at the presence of ATBC. The addition of ATBC into GLY plasticized starch/PVA/OMMT system enhanced the intermolecular interaction in the nanocomposites. This study proved that ATBC was an excellent compatibilizer in the preparation of starch/PVA/OMMT nanocomposite films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42544.     

Effect of magnesium chloride hexahydrate on thermal and mechanical properties of starch/PVA films

Starch/poly(vinyl alcohol) (PVA) blend films were prepared from the aqueous solutions containing starch, PVA and magnesium chloride hexahydrate (MgCl₂.6H₂O). The interaction between MgCl₂.6H₂O and starch/PVA was studied by Fourier transform infrared spectroscopy. The plasticising effect of MgCl₂.6H₂O on starch/PVA film was studied by scanning electron microscopy (SEM), X-ray diffraction, thermogravimetric analysis, dynamic mechanical analysis and tensile testing respectively. The water content of starch/PVA films increased with the content of MgCl₂.6H₂O. The absorbed water can act as the plasticiser for starch/PVA film. The crystals of starch and PVA were destroyed, and the crystallinity of starch/PVA film decreased with the plasticising effect of MgCl₂.6H₂O and water. SEM micrographs showed that the compatibility between starch and PVA improved with the addition of MgCl₂.6H₂O. The toughness of starch/PVA film increased with the content of MgCl₂.6H₂O.     

Effects of glycerol and PE‐g‐MA on morphology,thermal and tensile properties of LDPE and rice starch blends

The effects of glycerol and polyethylene‐grafted maleic anhydride (PE‐g‐MA) on the morphology, thermal properties, and tensile properties of low‐density polyethylene (LDPE) and rice starch blends were studied by scanning electron microscopy (SEM), differential scanning calorimetry, and the Instron Universal Testing Machine, respectively. Blends of LDPE/rice starch, LDPE/rice starch/glycerol, and LDPE/rice starch/glycerol/PE‐g‐MA with different starch contents were prepared by using a laboratory scale twin‐screw extruder. The distribution of rice starch in LDPE matrix became homogenous after the addition of glycerol. The interfacial adhesion between rice starch and LDPE was improved by the addition of PE‐g‐MA as demonstrated by SEM. The crystallization temperatures of LDPE/rice starch/glycerol blends and LDPE/rice starch/glycerol/PE‐g‐MA blends were similar to that of pure LDPE but higher than that of LDPE/rice starch blends. Both the tensile strength and the elongation at break followed the order of rice starch/LDPE/glycerol/PE‐g‐MA blends > rice starch/LDPE/glycerol > LDPE/rice starch blends. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 344–350, 2004     

Effect of glycerol on thermal and mechanical properties of polyvinyl alcohol/starch blends

The paper reports the results of studies on the effect of glycerol content on thermal, mechanical, and dynamic mechanical properties of blends of starch and polyvinyl alcohol (PVA). Degree of crystallinity of the starch/PVA blends (4 g/4 g ratio) remains almost constant up to 3.78 g of glycerol as determined by differential scanning calorimetry (DSC) and x‐ray diffraction studies. At higher loading of glycerol the crystallinity decreases. DTG thermograms revealed occurring of one maximum degradation temperature closer to that of starch in blends containing up to 3.78 g of glycerol. At higher glycerol content there gradually occur two distinct peaks of maximum degradation temperature, one occurring close to that of starch and other occurring close to the PVA peak, indicating phase separation of the blend components. Results of stress–strain studies indicate lowering of tensile properties and energy at break particularly at higher glycerol content (beyond 3.78 g). Dynamic mechanical studies reveal a sharp drop in dynamic modulus at higher glycerol content at all temperatures. The blend with low glycerol content shows transitions of starch, while the blend containing high glycerol content beyond 3.78 g display the transitions due to both starch and PVA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of unmodified and modified sago starch on properties of (sago starch)/silica/PVA plastic films

Sago starch was modified by crosslinking with sodium trimetaphosphate (STMP). Different formulations of films were prepared by a blending process and a casting method. A suitable plasticizer was added to the blend. Mechanical properties of plastic films with unmodified and modified sago starch were compared. From the results obtained, films with modified sago starch had better compatibility and interaction with polyvinyl alcohol than unmodified sago starch films. Thus, the tensile strength of modified films was higher, but lower in elongation at break than unmodified sago starch plastic films. Films with modified sago starch also showed lower water absorption, water vapor transmission, and degradation than unmodified sago starch plastic films. Chosen were 1 wt% and 2 wt% of silica as the optimum formulation that produced the best tensile properties for modified and unmodified sago starch plastic films. J. VINYL ADDIT. TECHNOL., 20:185–192, 2014. © 2014 Society of Plastics Engineers     

Effect of nano‐silica on the mechanical,thermal, and crystalline properties of poly(vinyl alcohol)/nano‐silica films

Poly(vinyl alcohol)/nano‐silica (PVA/nano‐SiO₂) films were prepared through extrusion blowing with the addition of water and glycerin as plasticizer. The characteristic properties of PVA/nano‐SiO₂ films were investigated by differential scanning calorimetry, dynamic mechanical analysis, Haake torque rheometry, and atomic force microscopy (AFM). The results showed that the mechanical properties of PVA/nano‐SiO₂ were improved dramatically. The tensile strength of the nanofilms increased from 62 MPa to 104 MPa with loading 0.3 wt % nano‐SiO₂ and the tear strength was improved from 222 KN/m to 580 KN/m. The crystallinity of the films loaded with 0.4 wt. % nano‐SiO₂ decreased from 32.2% to 21.0% and the AFM images indicated that the amorphous region of nanofilms increased with increasing nano‐SiO₂ content. The storage modulus and loss modulus increased to two and nearly three times with 0.3 wt % nano‐SiO₂ loading. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effects of plasticizer/cross-linker on the mechanical and thermal properties of starch/PVA blends

Biodegradable blends of potato starch and polyvinyl alcohol were prepared by solution casting method. Citric acid was employed to introduce the plasticizing effect into the starch materials. Glutaraldehyde as cross-linker was used to enhance the properties of the blend films. Cross-linking is a common method to improve the strength and stability of starch products. The effects of citric acid and glutaraldehyde on the mechanical properties, thermal properties and swelling degree were investigated. The prepared films were measured for their antibacterial activities and biodegradability. The blend samples were characterized by the thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and FTIR analysis techniques. From the mechanical properties study, it was analyzed that the blend films showed improvement in their tensile strength after cross-linking with glutaraldehyde. The SEM micrographs indicated that the blend films were smooth without any cracks, pores and were well cross-linked. The TGA curves showed that there was an increase in the thermal stability of the blend films after cross-linking as compared to uncross-linked blend films. The prepared films showed good antibacterial properties against Gam-positive and Gram-negative bacteria. The biodegradability of the blends was determined by placing the samples in compost soil for different time intervals and were found to be biodegradable in nature.     

Employment of ultrasonic waves for the preparation of PVA/TiO2‐BSA nanocomposites: Mechanical,thermal, and optical properties

The goal of this project is to obtain poly(vinyl alcohol) (PVA)/TiO₂‐bovine serum albumin (BSA) nanocomposite (NC) films in different weight percentages of modified TiO₂. For this purpose, to prevent the accumulation of nanoparticles (NPs) in the PVA matrix, the surface of the TiO₂ NPs was treated with the BSA molecules. To achieve this aim, ultrasonic waves were used as an environmentally friendly and green process that decrease the time of reactions, help better spreading of TiO₂ NPs and maintain dimensions of TiO₂ NPs in the nanoscale range. In the end, the features of the PVA/TiO₂‐BSA NC films were considered with a variety of techniques. The Fourier transform infrared spectroscopy, energy dispersive X‐ray, and X‐ray diffraction showed that the BSA was well placed on the surface of TiO₂ NPs. The thermal gravimetric analysis and UV‐visible results demonstrated that all the PVA/TiO₂‐BSA NC films have better thermal and optical properties than the pure PVA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46558.     

Effect of thermal aging on electrical conductivity of the 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid‐doped polyaniline fiber

The thermal characteristics of inherently conductive polyaniline (PANi) fiber have been studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Fibers show five major weight losses at ∼100°C, 165°C, 215°C, 315°C, and 465°C, which are associated with the removal of moisture, residual solvent, decompositions of the sulfonic acid and degradation of PANi fiber, respectively. The 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPSA) that dopes the PANi (in fiber form) performs two‐stage decompositions. The conductivity of the drawn fibers aged at 50°C, 100°C, 150°C, and 190°C under vacuum for various periods of time decreases, particularly at temperatures higher than 100°C. The reduction in conductivity of the fiber aged at temperatures lower than 100°C is mainly due to the evaporation of the residual solvent (15–20% in the as‐spun fiber). Further decrease in conductivity of the fiber aged at temperatures higher than 100°C is caused by the decomposition of the dopant AMPSA. The temperature‐dependent conductivity of the fiber was measured at 15 K (−258.5°C) to 295 K (21.5°C). The conductivity of both aged and un‐aged fibers is all temperature activated, however, the conductivity of the un‐aged fibers is higher than that of the aged fibers. Although a negative temperature coefficient was observed in the temperature range from 240 K (–24.5°C) to 270 K (–3.5°C) for the un‐aged fibers, it was disappeared when the fibers were thermal aged at 100°C for 24 h in vacuum oven. These results indicate that the residual solvent trapped inside the fiber enhanced the electrical conductivity of the fibers and its “metallic” electrical conductivity at temperatures ∼263 K (–10°C). © 2001 John Wiley & Sons, Inc. † J Appl Polym Sci 79: 2503–2508, 2001     

Effect of starch predrying on the mechanical properties of starch/poly(ε‐caprolactone) composites

This study describes the effect of predrying sago starch, a tropical starch, on the resultant mechanical properties of starch/poly(ε‐caprolactone) composite materials. Sago starch was dried to less than a 1% moisture level in a vacuum oven and dispersed into a polycaprolactone matrix with an internal mixer at 90°C. The mechanical properties of the composite were studied according to methods of the Association for Standards, Testing, and Measurement, whereas the morphology was monitored with scanning electron microscopy. The properties were compared with a composite obtained with native starch containing 12% moisture. The results indicated that predrying the starch led to a lower property drop rate in the composite as the starch content increased. The elastic modulus, tensile strength, and elongation at break were higher than those obtained when starch was used without predrying. The morphology observed during scanning electron microscopy studies was used to explain the observed trends in the mechanical properties. In this way, a relatively simple and cost‐effective method was devised to increase the starch loading in the polycaprolactone matrix to obtain properties within the useful range of mechanical properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 877–884, 2003     

Plasma treatment for enhancing mechanical and thermal properties of biodegradable PVA/starch blends

Two series of biodegradaable polyvinyl alcohol (PVA)/starch blends, i.e., PVA with/without plasma treatment (PP/P series), were produced by single‐screw extruder. The influences of plasma pretreatment and PVA content on the tensile properties, thermal behaviors, melt flow index, and biodegradability of blends were investigated. PVA pretreated by plasma (PPVA) reacted with glycerol was found not only to mechanically strengthen the PPVA/starch blend but also to improve the compatibility of PPVA and starch. Compared with PVA/starch blends, the melt flow indices of PPVA/starch blends were improved significantly by 200–300% and their tensile strength also increased two‐to‐three‐fold. Thermogravimetry analysis (TGA) showed that the thermal stability of PPVA/starch (85/300g) blend was better than PVA/starch blend at processing temperature and outperformed than PVA and starch at high temperature. Both the PPVA/starch and PVA/starch blends finished biodegradation within 9–10 weeks in soil burial tests. The esterification reaction of PPVA and glycerol was characterized by FTIR spectroscopic measurement and TGA test. The morphologic evolutions of the blend during biodegradation were investigated carefully by scanning electron microscope (SEM) imaging. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Properties and structural characterization of oxidized starch/PVA/α‐zirconium phosphate composites

Two series of composites, i.e., polyvinyl alcohol (PVA)/oxidized starch (OST)/exfoliated α‐zirconium phosphate (POST‐ZrPn) and PVA/starch (ST)/exfoliated α‐zirconium phosphate (PST‐ZrPn), were fabricated using a casting and solvent evaporation method. The composites were characterized by Fourier transform infrared spectroscopy (FT‐IR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (XRD), scanning electron microscopy (SEM), tensile testing, and moisture uptake. Compared with PST‐ZrPn, POST‐ZrPn films with the same component ratio showed higher tensile strength (σ_b), lower elongation at break (ε_b) and improved water resistance. Additionally, in the POST‐ZrPn series, σ_b and ε_b increased with an increase in α‐zirconium phosphate (α‐ZrP) loading; however, higher α‐ZrP loads resulted in the aggregation of α‐ZrP particles. Compared with POST‐ZrP0, the values for σ_b, ε_b, and water resistance of POST‐ZrP3, containing 1.5 wt % α‐ZrP, were increased by 128.8%, 51.4%, and 30.2%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of epoxidized natural rubber on the processing behavior,tensile properties,morphology, and thermal properties of linear‐low‐density polyethylene/soya powder blends

The effect of epoxidized natural rubber (ENR) with 50 mol% epoxidation (ENR 50) on the processing behaviors, tensile properties, morphology, and thermal properties of linear‐low‐density polyethylene (LLDPE)/soya powder blends was investigated. The LLDPE was blended with various soya powder contents in a Haake internal mixer at 150°C and a rotor speed of 50 rpm for 10 min. The tensile properties were tested by using an Instron tensometer according to ISO 527. The thermal stability of the blends was determined by using a thermogravimetric analyzer (TGA). The tensile strength and elongation at the breakage point were significantly improved by the addition of ENR 50, as evidenced by morphological analysis using scanning electron microscopy (SEM). On the other hand, the tensile modulus increased with soya powder content up to 20% and decreased thereafter. The crystallinity and crystallization temperatures of the blends decreased with the incorporation of ENR, and the thermal stability of the blends was lower with higher soya powder content. However, ENR 50 improved the thermal stability of LLDPE/soya powder blends. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

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.     

Influence of semi‐crystalline poly(ε‐caprolactone) and non‐crystalline polylactide blocks on the thermal properties of polydimethylsiloxane‐based block copolymers

Poly(A)‐block‐poly(B), poly(A)‐block‐poly(B)‐block‐poly(A) and B(A)₂ block copolymers were prepared through coordinated anionic ring‐opening polymerization of ε‐caprolactone (CL) and lactic acid (LA) using hydroxy‐terminated polydimethylsiloxane (PDMS) as initiator. A wide range of well‐defined combinations of PDMS‐block‐PCL and PDMS‐block‐PLA diblock copolymers, PCL‐block‐PDMS‐block‐PCL and PLA‐block‐PDMS‐block‐PLA triblock copolymers and star‐PDMS(PCL)₂ copolymers were thus obtained. The number‐average molar masses and the structure of the synthesized block copolymers were identified using various analytical techniques. The thermal properties of these copolymers were established using differential scanning calorimetry. Considering PDMS‐block‐PCL copolymers, the results demonstrate the complex effect of polymer architecture and PCL block length on the ability of the PDMS block to crystallize or not. In the case of diblock copolymers, crystallization of PCL blocks originated from stacking of adjacent chains inducing the extension of the PDMS block that can easily crystallize. In the case of star copolymers, the same tendency as in triblock copolymers is observed, showing a limited crystallization of PDMS when the length of the PCL block increases. In the case of PDMS‐block‐PLA copolymers, melting and crystallization transitions of the PLA block are never observed. Considering the diblock copolymers, PDMS sequences have the ability to crystallize. © 2019 Society of Chemical Industry     

Synergistic effect of α‐ZrP and graphene oxide nanofillers on the gas barrier properties of PVA films

Two types of 2D nanofillers, α‐zirconium phosphate (α‐ZrP) and graphene oxide (GO), were synthesized and incorporated into poly(vinyl alcohol) (PVA) with 1 wt % loading level at various α‐ZrP:GO (Z:G = 5:1, 2:1, 1:1, 1:2, and 1:5) ratios. The resulting nanocomposites were tested for barrier properties by casting films from solution. The structure and morphology of α‐ZrP and GO were characterized by Fourier‐transform infrared spectroscopy, atomic force microscope, scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction, which demonstrated successful preparation of exfoliated α‐ZrP and GO. The physical characteristics of the nanocomposite films, including thermal, mechanical, and gas barrier properties were investigated. The results indicated that the tensile strength, Young's modulus, and elongation at break of the PVA nanocomposite films with Z:G hybrid nanofiller improved compared to neat PVA. The glass transition temperature, melting temperature, and crystallinity also increased. Consequently there appears to be a synergistic effect with these two types of nanofillers that formed a specific macro structure of a “wall.” This macrostructure resulted in excellent O₂ gas barrier properties with the PVA/Z:G‐5:1 nanocomposite films having the best performance. The of the PVA/Z:G‐5:1 nanocomposite decreased from 1.835 × 10^?16 to 0.587 × 10^?16 cm³ cm cm^?2 s^?1 Pa^?1 compared with neat PVA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46455.     

Effect of ethylene‐1‐butene copolymer on tensile properties and toughness of polypropylene/mica/organoclay hybrid nanocomposites

In this study, polypropylene (PP) was reinforced using 1 wt% organically modified‐grafted mica (OMGM) and various levels of Cloisite15A (C15A), 0–3 wt%. For OMGM preparation, polypropylene graft maleic anhydride (PP‐g‐MAH) was grafted onto diacetone acryl amid modified mica. The results showed the highest impact strength enhancement of 68% and Young's modulus of 12% for hybrid nanocomposite containing 1 wt% OMGM and 0.5 wt% C15A when compared to neat PP. In order to considerably improve the impact strength of PP with advantage of elastic modulus enhancement, PP was melt blended with above‐mentioned amounts of OMGM and C15A and different contents of ethylene‐1‐butene copolymer (EBR), 0–10 wt%. The dispersion of low‐ and high‐aspect ratio layered silicate tactoids and EBR nanoparticles in the polymer matrix was studied using transmission electron microscopy. The effect of EBR level on the crystallization behavior, tensile properties, impact strength, and fracture toughness of the resultant toughened hybrid nanocomposite was investigated. The presence of EBR nanoparticles did not show any sufficient effect on the melting and crystallization temperatures of the toughened PP and hybrid nanocomposites. However, the impact results indicated that the addition of EBR to neat PP remarkably increased the toughness while sharply decreased its Young's modulus. The incorporation of 7 wt% EBR in the hybrid nanocomposite containing 1 wt% OMGM and 0.5 wt% C15A considerably enhanced impact strength 119% and 30% in comparison to neat PP and its hybrid nanocomposite, respectively. Additionally, the incorporation of EBR nanoparticle in the presence of the silicate layered nanoparticles prevented significant decreasing in Young's modulus of the matrix. J. VINYL ADDIT. TECHNOL., 25:117–126, 2019. © 2018 Society of Plastics Engineers     

Curing behavior and thermal and mechanical properties enhancement of tetraglycidyl‐4,4′‐diaminodiphenylmethane/4,4′‐diaminodiphenylsulfone using a liquid crystalline epoxy

A thermosetting resin system, based on tetraglycidyl‐4,4′‐diaminodiphenylmethane, has been developed via copolymerization with 4,4′‐diaminodiphenylsulfone in the presence of a newly synthesized liquid crystalline epoxy (LCE). The curing behavior of LCE‐containing resin system was evaluated using curing kinetics method and Fourier transform infrared spectroscopy. The effect of LCE on the thermal and mechanical properties of modified epoxy systems was studied. Thermogravimetric analysis indicated that the modified resin systems displayed a high T_0.05 and char yield at lower concentrations of LCE (≤5 wt%), suggesting an improved thermal stability. As determined using dynamic mechanical analysis and differential scanning calorimetry, the glass transition value increased by 9.7% compared to that of the neat resin when the LCE content was 5 wt%. Meanwhile, the addition of 5 wt% of LCE maximized the toughness with a 175% increase in impact strength. The analysis of fracture surfaces revealed a possible effect of LCE as a toughener and showed no phase separation in the modified resin system, which was also confirmed by dynamic mechanical analysis. © 2016 Society of Chemical Industry     

Synthesis,cure kinetics,and thermal properties of the Bis(3‐allyl‐2‐cyanatophenyl)sulphoxide/BMI blends

A novel allyl functionalized dicyanate ester resin bearing sulfoxide linkage was synthesized. The monomer was characterized by Fourier Transform Infrared (FT‐IR) Spectroscopy, ¹H‐, and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy and elemental analysis. The monomer was blended with bismaleimide (BMI) at various ratios in the absence of catalyst. The cure kinetics of one of the blends was studied using differential scanning calorimetry [nonisothermal] and the kinetic parameters like activation energy (E), pre‐exponential factor (A), and the order of the reaction (n) were calculated by Coats‐Redfern method and compared with those calculated using the experimental Borchardt‐Daniels method. The thermal stability of the cured dicyanate, BMI, and the blends was studied using thermogravimetric analyzer. The initial weight loss temperature of dicyanate ester is above 380°C with char yield of about 54% at 800°C. Thermal degradation of BMI starts above 463°C with the char yield of about 68%. Inclusion of BMI in cyanate ester increases the thermal stability from 419 to 441°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

In vitro degradation of starch/PVA films and biocompatibility evaluation

A series of starch/PVA (SP) films with the thickness of 0.05–0.1 mm were cast by solvent method. The swelling and degradation behaviors in simulated blood fluid (SBF) and simulated saliva fluid (SSF) within 30 days were investigated. In vitro biocompatibility was also evaluated. Research purpose of this work was to supply basic data for SP films' potential application in guide tissue regeneration (GTR) technology. It took 10–20 min for different samples to reach to their maximum water absorption and 30 min to lever off. The weight loss of all samples decreased rapidly in the first day in both of SBF or SSF, and then it changed slightly in SSF but decreased step by step in SBF. The mechanical properties of the wet SP films were satisfied with the requirement of GTR membrane. No matter in SBF or SSF, although the mechanical properties decreased rapidly in the first day, they changed slightly after that. Cytotoxicity and L929 fibroblasts attachment test proved that the SP film possesses excellent cell affinity. Hemolysis ratios of all samples were less than 5%. All results demonstrated that SP film is a promising candidate in GTR treatment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010