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1.
All Blend films were prepared from a mixture of 2 wt % chitosan in acetate solution and 4 wt % quaternized poly(4‐vinyl‐N‐butyl) pyridine (QPVP) in aqueous solution and dried at room temperature for 72 h to obtain the films. Their structure and properties were studied by infrared (IR), wide‐angle X‐ray diffraction (WXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Crystallinities of the blend films decreased with the increase of QPVP when weight of QPVP content was less than 15.0 wt %. The thermostability, tensile strength, and breaking elongation of the films in dry state were better than those of chitosan film. Tensile strength of the blend film dried at 40°C under vacuum for 24 h achieved 56.38 MPa when the weight ratio of chitosan to QPVP was 9 : 1. The structural analysis indicated that there was a strong interaction between chitosan and QPVP resulting from strong adhesion between both polymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 559–566, 2004  相似文献   

2.
BACKGROUND: Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [P(3HB‐co‐3HV)] co‐polymer has immense potential in the field of environmental and biomedical sciences as biodegradable and biocompatible material. The present study examines a filamentous N2‐fixing cyanobacterium, Nostoc muscorum Agardh as a potent feedstock for P(3HB‐co‐3HV) co‐polymer production and characterization of co‐polymer film for commercial applications. RESULTS: Under photoautotrophic growth conditions, N. muscorum Agardh accumulated the homopolymer of poly‐β‐hydroxybutyrate (PHB), whereas synthesis of P(3HB‐co‐3HV) co‐polymer was detected under propionate‐ and valerate‐supplemented conditions. Exogenous carbons such as acetate, fructose and glucose supplementation with propionate/valerate was found highly stimulatory for the co‐polymer accumulation; the content reached 58–60% of dry cell weight (dcw) under P‐/N‐deficiencies with 0.4% acetate + 0.4% valerate supplementation, the highest value reported so far for P(3HB‐co‐3HV) co‐polymer‐producing cyanobacterial species. The material properties of the films were studied by mechanical tests, surface analysis and differential scanning calorimetry (DSC). CONCLUSION: N. muscorum Agardh, a photoautotrophic N2‐fixing cyanobacterium, emerged as a potent host for production of P(3HB‐co‐3HV) co‐polymer with polymer content 60% of dry cell weight. The material properties of the films were found to be comparable with that of the commercial polymer, thus advocating its potential applications in various fields. Copyright © 2012 Society of Chemical Industry  相似文献   

3.
In order to enhance the mechanical properties of konjac glucomannan film in the dry state and research the application of konjac glucomannan on food preservation domain, blend transparent film was prepared by blending 3 wt % sodium alginate aqueous solution with 4.5 wt % konjac glucomannan aqueous solution and dried at 40oC for 4 h. The structure and properties of the blend films were studied by infrared, wide angle X‐ray diffraction, scanning electron microscopy, and differential thermal analysis. Crystallinities of blend films were increased with the increase of sodium alginate. The tensile strength and breaking elongation of the blend films in dry state were obviously higher than those of both sodium alginate and konjac glucomannan films. Tensile strength of the dry blend film achieved 77.8 MPa when the retention of sodium alginate in the film was 27.9 wt %. The structure analysis indicated that there was a strong interaction between konjac glucomannan and sodium alginate, and this is resulted from the intermolecular hydrogen bonds. Moisture content and degree of water swelling of the blend films were increased due to the introduction of sodium alginate. Results from the film coating preservation experiment to litchi and honey peach showed that this blend film had water‐holding ability. The fruit weight loss rate and rot rate both decreased by various values. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 617–626, 2000  相似文献   

4.
Novel polyion complexes films of chitosan and quarternized poly(4‐vinyl‐N‐carboxymethylpyridine) containing zwitterion structure units were prepared by casting method. The aim of this work was to produce a hydrophilic film with the potential use as a hydrophilic membranes of the types used in membranes distillation and osmotic distillation for separating azeotropic, close‐boiling, and aqueous organic mixtures. Their structure and properties were studied by infrared, wide‐angle X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, tensile tester, and swelling measurements. The results indicated that polyion complexes occurred between chitosan and quarternized poly (4‐vinyl‐N‐carboxymethylpyridine) containing zwitterion structure units. The thermostability of these blends decreased with the increase of quarternized poly(4‐vinyl‐N‐carboxymethylpyridine) content. Initially, appreciable improvement in tensile strength and breaking elongation were achieved with increase of quarternized poly(4‐vinyl‐N‐carboxymethyl‐pyridine) content to 30%, the maximum value of 46.65 MPa tensile strength and 25.67% breaking elongation were achieved, respectively. The maximum degree of swelling was achieved when the weight ratio of chitosan versus poly(4‐vinyl‐N‐carboxymethylpyridine) was 50 : 50. Meanwhile, the relationship between their structure and properties was also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

5.
High refractive index homogeneous hybrid materials were successfully prepared. The polymer matrix was the copolymer of methyl methacrylate, sulfur‐containing monomer 2,2′‐mercaptoethylsulfide dimethacrylate (MESDMA), and nanotitania was prepared by in situ solgel process of titanium n‐butoxide. The transmission electron microscope (TEM) study suggested that the hybrid was homogeneous without inorganic agglomerate, and the inorganic particles were 4–7 nm. The refractive index was ~ 1.75 when the inorganic content of the hybrid film reached to 70 wt %, and the transmittance maintained up to 85%. The sulfur‐containing monomer was used to improve the refractive index, also, it was a crosslinking reagent, which improved the film‐forming ability of the hybrid. After copolymerized with MESDMA, the film‐forming ability of the hybrid was better than the one without MESDMA. Even if the inorganic content exceeded 75 wt %, the films kept integrity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

6.
Regenerated cellulose/chitin blend films (RCCH) were satisfactorily prepared in 6 wt % NaOH/4 wt % urea aqueous solution by coagulating with 5 wt % CaCl2 aqueous solution then treating with 1 wt % HCl. The structure, miscibility, and mechanical properties of the RCCH films were investigated by infrared, scanning electron microscopy, ultraviolet spectroscopies, X‐ray diffraction, tensile test, and differential scanning analysis. The results indicated that the blends were miscible when the content of chitin was lower than 40 wt %. Moreover, the RCCH blend film achieved the maximum tensile strength in both dry and wet states of 89.1 and 43.7 MPa, respectively, indicating that the tensile strength and water resistivity of the RCCH film containing 10–20 wt % chitin was slightly higher than that of the RC film unblended with chitin. Structural analysis indicated that strong interaction occurred between cellulose and chitin molecules caused by intermolecular hydrogen bonding. Compared to the mechanical properties of chitin film, those of the blend films containing 10–50 wt % chitin were significantly improved. This work provided a novel way to obtain directly chitin material blended in the aqueous solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1679–1683, 2002  相似文献   

7.
The electro‐optic performance characteristic of polymer‐dispersed liquid crystal (PDLC) composite films out of poly(vinyl butyral) (PVB) and nematic liquid crystal (E7) have been studied for a wide range of PVB–E7 composite compositions (20–70 wt % of E7). Composites were prepared by solvent casting from chloroform at room temperature. A scanning electron microscopy study showed that a E7 phase is continuously embedded in chink‐like structure of PVB matrix. Optical transmittance of the composite films (of 60 and 70 wt % loading of E7) under an alternating current (ac) electric field (0–250, Vpp) and frequency (50 Hz to 1 KHz) were measured employing He Ne laser (λ = 632.8 nm). The results indicate that the (PVB–E7) composite exhibits a memory effect. In the memory state, higher transmittance is preserved without applying voltage. The memory state can be erased and changed to the scattering Off‐state by heating the film to the clearing temperature of the liquid crystal. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3485–3491, 1999  相似文献   

8.
Single‐walled carbon nanotube (SWNT)/cellulose nanocomposite films were prepared using N‐methylmorpholine‐N‐oxide (NMMO) monohydrate as a dispersing agent for the acid‐treated SWNTs (A‐SWNTs) as well as a cellulose solvent. The A‐SWNTs were dispersed in both NMMO monohydrate and the nanocomposite film (as confirmed by scanning electron microscopy) because of the strong hydrogen bonds of the A‐SWNTs with NMMO and cellulose. The mechanical properties, thermal properties, and electric conductivity of the nanocomposite films were improved by adding a small amount of the A‐SWNTs to the cellulose. For example, by adding 1 wt % of the A‐SWNTs to the cellulose, tensile strain at break point, Young's modulus, and toughness increased ~ 5.4, ~ 2.2, and ~ 6 times, respectively, the degradation temperature increased to 9°C as compared with those of the pure cellulose film, and the electric conductivities at ? (the wt % of A‐SWNTs in the composite) = 1 and 9 were 4.97 × 10?4 and 3.74 × 10?2 S/cm, respectively. Thus, the A‐SWNT/cellulose nanocomposites are a promising material and can be used for many applications, such as toughened Lyocell fibers, transparent electrodes, and soforth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

9.
In this study, the degradability of linear low‐density polyethylene (LLDPE) and poly(L ‐lactic acid) (PLLA) blend films under controlled composting conditions was investigated according to modified ASTM D 5338 (2003). Differential scanning calorimetry, X‐ray diffraction, and Fourier transform infrared spectroscopy were used to determine the thermal and morphological properties of the plastic films. LLDPE 80 (80 wt % LLDPE and 20 wt % PLLA) degraded faster than grafted low‐density polyethylene–maleic anhydride (M‐g‐L) 80/4 (80 wt % LLDPE, 20 wt % PLLA, and 4 phr compatibilizer) and pure LLDPE (LLDPE 100). The mechanical properties and weight changes were determined after composting. The tensile strength of LLDPE 100, LLDPE 80, and M‐g‐L 80/4 decreased by 20, 54, and 35%, respectively. The films, as a result of degradation, exhibited a decrease in their mass. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

10.
Compatibilization of polymer blends of high‐impact polystyrene (HIPS) and high‐density polyethylene (HDPE) blend by styrene/ethylene–butylene/styrene (SEBS) was elucidated. Polymer blends containing many ratios of HIPS and HDPE with various concentrations of SEBS were prepared. The Izod impact strength and elongation at break of the blends increased with increases in SEBS content. They increased markedly when the HDPE content was higher than 50 wt %. Tensile strength of blends increased when the SEBS concentration was not higher than 5 pphr. Whenever the SEBS loading was higher than 5 pphr, the tensile strength decreased and a greater decrease was found in blends in which the HDPE concentration was more than 50 wt %. The log additivity rule model was applied to these blends, which showed that the blends containing the HIPS‐rich phase gave higher compatibility at the higher shear rates. Surprisingly, the blends containing the HDPE‐rich phase yielded greater compatibility at the lower shear rates. Morphology observations of the blends indicated better compatibility of the blends with increasing SEBS concentration. The relaxation time (T2) values from the pulsed NMR measurements revealed that both polymer blends became more compatible when the SEBS concentration was increased. When integrating all the investigations of compatibility compared with the mechanical properties, it is possible to conclude that SEBS promotes a certain level of compatibilization for several ratios of HIPS/HDPE blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 742–755, 2004  相似文献   

11.
Polyhydroxybutyrate‐co‐valerate (PHBV) is attracting interest as a new material for packaging applications and nanoparticulate layered silicates are being increasingly explored as a way to improve PHBV film properties. In this context, it is essential to understand how different types of nanofillers could influence polymer properties. PHBV was processed with three‐layered clay types using different mixing methods, and we examined the effect of processing time, clay type, and clay content on polymer molecular weight and composite morphology. PHBV molecular weight (Mw) decreased by 38% after extrusion processing and was further reduced in the presence of montmorillonite (MMT). However, when PHBV was processed with kaolinite as the additive, no further reduction in polymer molecular weight was observed. Molecular weight also decreased as the MMT clay content increased from 1 to 5 wt %. The results suggest that release of tightly bound water from clay surfaces at elevated temperature may be responsible for PHBV degradation during processing. Evidence also points to the possibility that the surface modifier present in organically modified MMT may catalyze PHBV degradation in some way. X‐ray diffraction studies indicated an intercalated morphology in the presence of modified montmorillonite but good dispersion was also achieved when unmodified kaolinite was blended with PHBV. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

12.
Alginate/ N‐Succinyl‐chitosan (SCS) blend fibers, prepared by spinning their mixture solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl2, were studied for structure and properties with the aid of infrared spectroscopy (IR) and X‐ray diffraction (XRD). The results indicated a good miscibility between alginate and SCS, because of the strong interaction from the intermolecular hydrogen bonds. The best values of the dry tensile strength and breaking elongation were obtained when SCS content was 30 wt %. The wet tensile strength decreased with the increase of SCS content, and the wet breaking elongation achieved maximum value when the SCS content was 30 wt %. Introduction of SCS in the blend fiber improved water‐retention properties of blend fiber compared to pure alginate fiber. Antibacterial fibers, obtained by treating the fibers with aqueous solution of silver nitrate, exhibited good antibacterial activity to Staphylococcus aureus. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

13.
We prepared a semi‐IPN (interpenetrating network)‐type solid polymer electrolyte (SPE) using poly (ethylene glycol)dimethacrylate (PEGDMA) as a polymer matrix containing a monocomb‐type poly(siloxane‐g‐allyl cyanide) and poly(ethylene glycol)dimethylether (PEGDME) for the lithium secondary battery. The poly(siloxane‐g‐allyl cyanide)s were prepared by a hydrosilation reaction of poly (methyl hydrosiloxane) with allyl cyanide and characterized by 1H NMR and FTIR. The semi‐IPN‐type electrolyte was prepared by thermal curing, and conductivities of samples were measured by impedance spectroscopy using an indium tin oxide (ITO) electrode. The ionic conductivity of the semi‐IPN‐polymer electrolyte was about 1.05 × 10?5 S cm?1 with 60 wt % of the poly(siloxane‐g‐allyl cyanide) and 6.96 × 10?4 S cm?1 with 50 wt % of the PEGDME and 10 wt % of the poly(siloxane‐g‐allyl cyanide) at 30°C. The SEM morphology of the cross section of the semi‐IPN‐polymer electrolyte film was changed from discontinuous network to continuous network as increasing the PEGDME content and decreasing the poly(siloxane‐g‐allyl cyanide) content. The mechanical stability was also enhanced when increasing the PEGDME content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

14.
Nanocomposites based on biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) and layered silicates were prepared by the melt intercalation method. Nonmodified montmorillonite (MMT) and organo‐modified MMTs (DA‐M, ODA‐M, and LEA‐M) by the protonated ammonium cations of dodecylamine, octadecylamine, and N‐lauryldiethanolamine, respectively, were used as the layered silicates. The comparison of interlayer spacing between clay and PBAT composites with inorganic content 3 wt % measured by X‐ray diffraction (XRD) revealed the formation of intercalated nanocomposites in DA‐M and LEA‐M. In case of PBAT/ODA‐M (3 wt %), no clear peak related to interlayer spacing was observed. From morphological studies using transmission electron microscopy, the ODA‐M was found to be finely and homogeneously dispersed in the matrix polymer, indicating the formation of exfoliated nanocomposite. When ODA‐M content was increased, the XRD peak related to intercalated clay increased. Although the exfoliated ODA‐M (3 wt %) nanocomposite showed a lower tensile modulus than the intercalated DA‐M and LEA‐M (3 wt %) composites, the PBAT/ODA‐M composite with inorganic content 5 wt % showed the highest tensile modulus, strength, and elongation at break among the PBAT composites with inorganic content 5 wt %. Their tensile properties are discussed in relation to the degree of crystallinity of the injection molded samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 386–392, 2005  相似文献   

15.
An acrylate‐modified tung‐oil waterborne insulation varnish was synthesized from tung oil, maleic anhydride, and acrylates via a Diels–Alder reaction and free‐radical polymerization, and the varnish could be solidified at a relatively low temperature with blocked hexamethylene diisocyanate as a curing agent. The resulting films were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The insulation properties (electrical insulation strength, volume resistivity, and surface resistivity) of the varnish films were tested, and the resistances of films to salted water were evaluated. With an increase in the maleic anhydride content, the thermal stability of the film was improved, whereas the electrical insulation strength, volume resistivity, and surface resistivity decreased. The electrical insulation strength of the film after it was immersed in the NaCl solution was lower than that in dry state, and it decreased as the immersed time was prolonged. In particular, the electrical insulation strength loss of the film increased significantly at maleic anhydride contents beyond 25 wt %. Furthermore, the hardness of the film increased with increasing methyl methacrylate/N‐butyl acrylate ratio, whereas the flexibility and adhesion of film decreased to a certain degree at the same time. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41608.  相似文献   

16.
The aim of this work was to prepare a hydrophilic film which can be applied in membrane separation. This hydrophilic film was obtained by blending alginate and quaternized poly(4-vinyl-N–carboxymethylpyridine) (QPVP) containing zwitterion structure units. The films were characterized by infrared, wide-angle X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, tensile testing and water adsorption. The results indicated that strong interaction occurred between alginate and QPVP. The thermal stability of the blend was weakened with increasing the amount of QPVP. At a QPVP loading of 30 %, the tensile strength can reach the maximum value of 53.5 MPa while the breaking elongation arrives to 16 %. The water absorption has also been investigated in differential ratio of ethanol versus water. Meanwhile, the relationship between their structure and properties was also discussed.  相似文献   

17.
An experimental study of the spinnability and the variation in crystallinity and orientation of melt spinning of poly(ethylene‐co‐octene) with different contents of comonomers was carried out. The spinning behavior of these polymers was investigated under different draw‐down ratios and temperatures and correlated to spinline stress. The melt‐spun filaments were characterized by wide‐angle X‐ray diffraction birefringence, and differential scanning calorimetry. S‐1 is a high‐density polyethylene and S‐2, S‐3, and S‐4 have 16, 22, and 38 wt % octene. An orthorhombic unit cell was found in all four polymers, but a dominant hexagonal structure (perhaps mesophase) was found for the highest octene level (S‐4). The orientation factors for the a‐, b‐, and c‐axis of the orthorhombic crystal structure and a‐axis of the hexagonal phase were then calculated. The crystalline orientation behavior of the lower octene copolymers (S‐1, S‐2, and S‐3) are similar and can be represented as a “row‐nucleated“ structure. However, the orientation behavior of S‐4 was different. The uniaxial mechanical properties were also measured. The Young's modulus and tensile strength generally increased with birefringence for all polymers. With increasing content of octene, the Young's modulus showed a decrease from semicrystalline thermoplastic toward an elastomer. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 9–22, 2004  相似文献   

18.
Crosslinked alginate‐based nanocomposites at different SiO2 contents were prepared successfully by blending the nano‐SiO2 solution into low concentration alginate solution (0.5 wt %), with the alginate concentration increased step by step to the resulted concentration, in this course glycerol was used as plasticizer and 5 wt % CaCl2 as crosslinker. The combined effect of SiO2 content (1.5–8 wt %) on the microstructural, physical, mechanical, and optical properties of the nanocomposite films were investigated. The results showed that tensile strength and elongation was improved by about 40.33% and 89%, respectively, upon increasing the SiO2 content to 4.5 wt %. In addition, water vapor permeability and swelling degree decreased by 19% and 16% with increasing SiO2 content up to 8 and 4.5 wt %, respectively with respect to pure crosslinked alginate film. Thermogravimetric analysis also revealed that nano‐SiO2 can improve the thermal stability of sodium alginate films produced by this method. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45286.  相似文献   

19.
A novel fluorinated diamine monomer, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride with 2,2‐bis(4‐hydroxyphenyl)propane in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides were synthesized from diamine 2 and various aromatic dianhydrides 3a–f via thermal imidization. These polymers had inherent viscosities ranging from 0.73 to 1.29 dL/g. Polyimides 5a–f were soluble in amide polar solvents and even in less polar solvents. These films had tensile strengths of 87–100 MPa, elongations to break of 8–29%, and initial moduli of 1.7–2.2 GPa. The glass transition temperatures (Tg) of 5a–f were in the range of 222–271°C, and the 10% weight loss temperatures (T10) of them were all above 493°C. Compared with polyimides 6 series based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane (BAPP) and polyimides 7 based on 2,2‐Bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane (6FBAPP), the 5 series showed better solubility and lower color intensity, dielectric constant, and lower moisture absorption. Their films had cutoff wavelengths between 363 and 404 nm, b* values ranging from 8 to 62, dielectric constants of 2.68–3.16 (1 MHz), and moisture absorptions in the range of 0.04–0.35 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 922–935, 2005  相似文献   

20.
Novel aqueous polyurethane (PU) hybrid dispersions were successfully prepared with 5–15 mol % functionalized hexamethylene diisocynate trimer modified by N‐(n‐butyl)‐3‐aminopropyltriethoxysilane and dihydroxylpropyl‐terminated siloxane oligomers (TS). The results of the differential scanning calorimetry and X‐ray diffraction tests show that the degree of segment order was reduced by the introduction of TS. The hybrid polymer films with TS introduced into the PU backbone displayed excellent water and xylene resistance. Atomic force microscopy showed that the films had a smooth surface. It was noticeable that the tensile strength (σb) and Young's modulus of the films increased simultaneously when TS was incorporated into PU; σb of the PU15 film with 15 mol % TS was much higher than that of the neat PU0 film, and the breaking elongation of the film with 10 mol % TS was clearly higher than that of the other films. The results indicate that an appropriate content of TS significantly improved the properties of the aqueous PU hybrids. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

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