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1.
The purpose of this work was to improve the properties of the starch/poly(vinyl alcohol) (PVA) films with nano silicon dioxide (nano SiO2). Starch/PVA/nano‐SiO2 biodegradable blend films were prepared by a solution casting method. The characteristics of the films were assessed by Fourier Transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). The results obtained in this study indicated that the nano‐SiO2 particles were dispersed evenly within the starch/PVA coating and an intermolecular hydrogen bond and a strong chemical bond C? O? Si were formed in the nano‐SiO2 and starch/PVA. That the blending of starch, PVA and nano‐SiO2 particles led to uniform starch/PVA/nano‐SiO2 blend films with better mechanical properties. In addition, the nano‐SiO2 particles can improve the water resistance and light transmission of the blend films. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

2.
In the present study, fumed silica (SiO2) nanoparticle reinforced poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) blend nanocomposite films were prepared via a simple solution‐blending technique. Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to elucidate the successful incorporation of SiO2 nanoparticles in the PVA/PVP blend matrix. A thermogravimetric analyzer was used to evaluate the thermal stability of the nanocomposites. The dielectric properties such as dielectric constant (?) and dielectric loss (tan δ) of the PVA/PVP/SiO2 nanocomposite films were evaluated in the broadband frequency range of 10?2 Hz to 20 MHz and for temperatures in the range 40–150 °C. The FTIR and UV–vis spectroscopy results implied the presence of hydrogen bonding interaction between SiO2 and the PVA/PVP blend matrix. The XRD and SEM results revealed that SiO2 nanoparticles were uniformly dispersed in the PVA/PVP blend matrix. The dielectric property analysis revealed that the dielectric constant values of the nanocomposites are higher than those of PVA/PVP blends. The maximum dielectric constant and the dielectric loss were 125 (10?2 Hz, 150 °C) and 1.1 (10?2 Hz, 70 °C), respectively, for PVA/PVP/SiO2 nanocomposites with 25 wt % SiO2 content. These results enable the preparation of dielectric nanocomposites using a facile solution‐casting method that exhibit the desirable dielectric performance for flexible organic electronics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44427.  相似文献   

3.
This paper details an improvement in the properties of poly(ethylene terephthalate) (PET) with respect to its use in petroleum engineering by incorporating uniform (monodisperse; 35 to 380 nm) silica (SiO2) particles and polystyrene? SiO2 core–shell particles by melt mixing. The resulting high‐performance nanocomposite (SNPET) films are presented. The results of contact angle and water absorption tests showed that the contact angle of the amorphous SNPET films increased from 72° to 118.5° as the core–shell particle load increased from 0 to 6.0 wt%. The contact angle reached 128.0° when the films were annealed. Decreasing the SiO2 particle size demonstrably improved the SNPET film hydrophobicity and lowered the water diffusion coefficient, i.e. SiO2 particles of 35 nm in size gave the greatest enhancement of water barrier properties. Results of transmission electron microscopy, scanning electron microscopy, atomic force microscopy and optical measurements showed the homogeneous particle dispersion and nanostructure in the SNPET films. Their transparency and haziness increased as the particle size decreased. Use of such core–shell structures meant that the uniform (monodisperse) SiO2 particles could be dispersed homogeneously in PET, and effectively improved the surface, thermal and crystallization behavior of SNPET films to produce materials with high barrier stability against water. Copyright © 2010 Society of Chemical Industry  相似文献   

4.
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  相似文献   

5.
A series of LDPE/PVA blend films were prepared via a twin‐screw extruder, and their morphology, thermal property, oxygen and water vapor permeation, surface properties, and mechanical properties were investigated as a function of the PVA content. During the extrusion process of the blend films, glycerin improved the compatibility and processing conditions between LDPE and PVA. The melting temperature (Tm), melting enthalpy (ΔHm), crystallinity (%), and thermal stability of the thermal decomposition temperature (T5%) of the LDPE/PVA blend films decreased with increasing PVA content. The oxygen permeabilities of the blend films decreased from 24.0 to 11.4 cm3·cm (m2·day·atm)?1 at 23°C. The WVTR increased from 7.8 to 15.0 g(m2 day)?1 and the water uptake increased from 0.13 to 9.31%, respectively. The mechanical properties of blend films were slightly enhanced up to 2% PVA and then decreased. The physical properties of the blend films strongly varied with the chemical structure and morphology depending on the PVA and glycerin. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41985.  相似文献   

6.
Blend films were prepared from hydrophobic poly(L -lactide) (PLLA) and hydrophilic poly(vinyl alcohol) (PVA) with different PLLA contents [XPLLA (w/w) = PLLA/(PVA + PLLA)] by solution casting and melt quenching. Their morphology, swelling behavior, and surface and bulk properties were investigated. Polarizing optical microscopy, scanning electron microscopy, differential scanning calorimetry, X-ray diffractometry, and tensile testing revealed that PLLA and PVA were phase separated in these blend films and the PLLA-rich and PVA-rich phases both formed a continuous domain in the blend film of XPLLA = 0.5. The water absorption of the blend films was higher for the blend films of low XPLLA values when compared at the same immersion time, and it was larger than expected from those of nonblended PLLA and PVA films. The dynamic contact angles of the blend films were linearly increased with an increase in XPLLA. The tensile strength and Young's modulus of the dry blend films decreased with a rise in XPLLA, but this dependence was reversed because of the large decreases in tensile strength and Young's modulus for the blend films having high XPLLA values after immersion in water. The elongation at break was higher for the wet blend film than for the dry blend film when compared at the same XPLLA and that of the dry and wet blend films decreased with an increase in XPLLA. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2151–2160, 2001  相似文献   

7.
Nanocomposite particles of poly(chlorotrifluoroethylene‐co‐ethylvinyl ether) [poly(CTFE‐co‐EVE)]/poly(styrene acrylate) (PSA)/SiO2 were prepared with poly(CTFE‐co‐EVE)/PSA [CS(FS); core–shell (CS) fluoro surfactant (FS)] and hydrophilic SiO2 nanoparticles by a solution mixing method. This method yielded a homogeneous dispersion of hydrophilic SiO2 nanoparticles in the CS(FS) matrix. The nanocomposite particle composition was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. A slight improvement in the thermal stability was observed and the glass‐transition temperature of the nanocomposite particles increased compared with the CS(FS) matrix. A remarkable enhancement was observed in the mechanical properties with an increase in the tensile strength from 1.1 to 6.2 MPa and with an increase in the elongation at break from 209.6 to 350.1% for the films with 15 wt % SiO2. The presence of a wettable PSA shell on the fluorocore made interaction possible with SiO2; this made it more hygroscopic with a decent water uptake capacity and an enhanced water contact angle. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012  相似文献   

8.
壳聚糖/聚乙烯醇共混膜的氢键和相容性   总被引:5,自引:0,他引:5       下载免费PDF全文
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%。  相似文献   

9.
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.  相似文献   

10.
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  相似文献   

11.
In this study, PVA‐SiO2 was synthesized by modifying silica (SiO2) with polyvinyl alcohol (PVA), then a novel polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane was prepared by incorporating the prepared PVA‐SiO2 into membrane matrix using the non‐solvent induced phase separation (NIPS) method. The effects of PVA‐SiO2 particle on the properties of the PVDF membrane were systematically studied by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT‐IR), surface pore size, porosity, and water contact angle. The results indicated that with the addition of PVA‐SiO2 particles in the PVDF UF membranes, membrane mean pore size increased from 80.06 to 126.00 nm, porosity improved from 77.4% to 89.1%, and water contact angle decreased from 75.61° to 63.10°. Furthermore, ultrafiltration experiments were conducted in terms of pure water flux, bovine serum albumin (BSA) rejection, and anti‐fouling performance. It indicated that with the addition of PVA‐SiO2 particles, pure water flux increased from 70 to 126 L/m2 h, BSA rejection increased from 67% to 86%, flux recovery ratio increased from 60% to 96%, total fouling ratio decreased from 50% to 18.7%, and irreversible fouling ratio decreased from 40% to 4%. Membrane anti‐fouling property was improved, and it can be expected that this work may provide some references to the improvement of the anti‐fouling performance of the PVDF ultrafiltration membrane. POLYM. ENG. SCI., 59:E412–E421, 2019. © 2018 Society of Plastics Engineers  相似文献   

12.
Hydroxypropyltrimethylammonium chloride cellulose (CM) was homogeneously synthesized in a NaOH/urea aqueous solution. CM was blended in a polyvinyl alcohol (PVA) matrix to produce composite films via co‐regeneration from the alkaline solution. The PVA film and the blend films were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction measurements and scanning electron microscopy. The mechanical properties, water swelling ratio, hydrophobicity, light transmission, and antibacterial activity against Staphylococcus aureus and Escherichia coli were also evaluated. The results showed that CM could interact with PVA by hydrogen bonding and exhibit an obvious reinforcement effect. The addition of CM improved the surface roughness, hydrophobicity and water swelling ratio, especially, the antibacterial activity. However, compared with neat PVA film, the elasticity and optical transmission decreased. The increased tensile strength, powerful antibacterial activity, and medium light transmission indicate that the biocompatible blend film will become an exceptional alternative in functional bio‐material field. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43552.  相似文献   

13.
[Halloysite nanotubes (HNT)]‐filled and kaolin filled composite films based on poly(vinyl alcohol) (PVA)/chitosan (CS) blend were prepared via solution casting method. Tensile properties, fracture morphology, FTIR spectra, thermal stability, swelling properties, moisture absorption, and oxidative degradation of the composite films were investigated. Addition of 0.5 wt% of filler led to the optimum tensile properties of the films. Increased roughness and tearing in the fracture surface morphology supported the tensile results. The FTIR results indicated there were physical interactions present in the composite films. Thermal stability of the composite films differed slightly where PVA/CS/HNT composite films showed better thermal stability than PVA/CS/kaolin composite films. Moreover, the presence of HNT and kaolin fillers in the blend reduced the swelling and moisture absorption properties of the films. Finally, the composite films were degraded by using Fenton's reagent. Degradation percentage of the composite films decreased with increasing filler loading. J. VINYL ADDIT. TECHNOL., 19:55–64, 2013. © 2013 Society of Plastics Engineers  相似文献   

14.
Water‐swollen hydrogel (WSH) membranes for gas separation were prepared by the dip‐coating of asymmetric porous polyetherimide (PEI) membrane supports with poly(vinyl alcohol) (PVA)–glutaraldehyde (GA), followed by the crosslinking of the active layer by a solution method. Crosslinked PVA/GA film of different blend compositions (PVA/GA = 1/0.04, 0.06, 0.08, 0.10, 0.12 mol %) were characterized by differential scanning calorimetry (DSC) and their water‐swelling ratio. The swelling behavior of PVA/GA films of different blend compositions was dependent on the crosslinking density and chemical functional groups created by the reaction between PVA and GA, such as the acetal group, ether linkage, and unreacted pendent aldehydes in PVA. The permeation performances of the membranes swollen by the water vapor contained in a feed gas were investigated. The behavior of gas permeation through a WSH membrane was parallel to the swelling behavior of the PVA/GA film in water. The permeation rate of carbon dioxide through the WSH membranes was 105 (cm3 cm?2 s?1 cmHg) and a CO2/N2 separation factor was about 80 at room temperature. The effect of the additive (potassium bicarbonate, KHCO3) and catalyst (sodium arsenite, NaASO2) on the permeation of gases through these WSH membranes was also studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1785–1791, 2001  相似文献   

15.
A series of poly(vinyl alcohol) (PVA)/regenerated silk fibroin (RSF)/nano-silicon dioxide (nano-SiO2) blend films were prepared by solution casting method, in which nano-SiO2 was obtained via sol?Cgel process. The structure, properties, and morphology of the films related to the compatibility were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). XRD peaks of PVA/RSF/nano-SiO2 (1.0?wt?%) blends decreased in intensity indicated that formation of PVA and RSF crystal lattices was hindered by nano-SiO2 particles. FTIR spectroscopy analysis of PVA/RSF/nano-SiO2 films confirmed that both Si?CO?CC linkage and hydrogen bonding were formed among PVA, RSF, and nano-SiO2. SEM showed that there was no obvious phase separation in PVA/RSF/nano-SiO2 (1.0?wt?%) film although small uniform blur particles can still be found. In addition, TEM showed nano-particles were well dispersed through the PVA/RSF polymer matrix. Besides, the observed shift in glass transition temperatures (T g) and improvement in thermal properties of composite films suggested the enhanced compatibility due to interfacial bonding and intermolecular interactions. Therefore, these results indicated that the compatibility of PVA/RSF was improved effectively by the addition of nano-SiO2.  相似文献   

16.
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.  相似文献   

17.
Thiol-functionalized mesoporous poly (vinyl alcohol)/SiO2 composite nanofiber membranes and pure PVA nanofiber membranes were synthesized by electrospinning. The results of Fourier transform infrared (FTIR) indicated that the PVA/SiO2 composite nanofibers were functionalized by mercapto groups via the hydrolysis polycondensation. The surface areas of the PVA/SiO2 composite nanofiber membranes were >290 m2/g. The surface areas, pore diameters and pore volumes of PVA/SiO2 composite nanofibers decreased as the PVA content increased. The adsorption capacities of the thiol-functionalized mesoporous PVA/SiO2 composite nanofiber membranes were greater than the pure PVA nanofiber membranes. The largest adsorption capacity was 489.12 mg/g at 303 K. The mesoporous PVA/SiO2 composite nanofiber membranes exhibited higher Cu2+ ion adsorption capacity than other reported nanofiber membranes. Furthermore, the adsorption capacity of the PVA/SiO2 composite nanofiber membranes was maintained through six recycling processes. Consequently, these membranes can be promising materials for removing, and recovering, heavy metal ions in water.  相似文献   

18.
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 (Tg) 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 (σb) 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  相似文献   

19.
The purpose of this article is to investigate the effects of nano‐tianium dioxide (nano‐TiO2) on the high‐amylose starch/polyvingl alcohol (PVA) blend films prepared by a solution casting method. The results show that at the concentration of 0.6% of nano‐TiO2, the film demonstrated the best tensile strength at 9.53 MPa, and the elongation at break was noted as 49.50%. The optical transmittance of the film was decreased and the water resistance was improved with further increase of the concentration of nano‐TiO2. Using the techniques of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and field‐emission scanning electron microscopy (SEM), the molecular and the crystal structures of the films were characterized. The results indicate that the miscibility and compatibility between high‐amylose starch and PVA were increased with the addition of nano‐TiO2 into the films due to the formation of hydrogen and C? O? Ti bonds. The antimicrobial activities of the blend films were also explored. The results show that there were inhibitory zones around the circular film disc, which is attributable to the addition of nano‐TiO2. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42339.  相似文献   

20.
《Ceramics International》2022,48(20):30307-30316
The design of magnetic composite scaffolds with superior properties has the potential to construct a targeted delivery platform with hyperthermia. In this study, strontium hexaferrite (SrFe12O19, SrM) magnetic nanoparticles (MNPs) were obtained by the chemical precipitation method. Non-toxic cross-linked biogels were prepared for adhesive ceramic scaffolds, and chitosan/polyvinylalcohol (CS/PVA)-bonded SrM magnetic nanoscaffolds were successfully prepared by 3D gel printing (3DGP) method. The effects of PVA physical cross-linking and in situ formed SiO2 on the properties of CS-bonded scaffolds were evaluated, and the compressive strengths were increased from 6.13 ± 2.45 MPa to 8.80 ± 2.02 MPa and 17.18 ± 2.15 MPa, respectively. The results showed that the saturation magnetization of SiO2/CS/PVA/SrM composite scaffolds was 59.96 emu/g. In vitro immersion experiments showed that the degradation rates of SiO2/CS/PVA/SrM scaffolds were 4.90% after 28 days, and the in situ SiO2 improved the deposition of calcium salts on the scaffolds. The experiments showed that the SrM magnetic scaffolds could not only concentrate magnetic fields to improve the efficiency of targeting deposition but also achieve a weak targeting process without external magnetic field assistance. In vitro cell proliferation test showed that MC3T3-E1 cells had good adhesion and proliferation on the surface of SiO2/CS/PVA/SrM scaffolds, which indicated that the scaffolds may be used for bone repairing.  相似文献   

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