The utilization of poly(amide-imide)/SiO2 nanocomposite as nanofiller for strengthening of mechanical and thermal properties of poly(vinyl alcohol) nanocomposite films

The present investigation reports the preparation and characterization of the thermally stable poly(vinyl alcohol)/(poly(amide-imide)-SiO₂) nanocomposite (PVA/PAI-SiO₂ NC) films. For this reason, the surface of SiO₂ nanoparticles (NPs) was modified with N-trimellitylimido-l-methionine and subsequently, 5 wt.% of modified SiO₂ NPs were dispersed in the PAI matrix via sonochemical reaction. The resulting NC was studied by different techniques. Finally, the PAI-SiO₂ NC was employed as nanofiller and was incorporated into the PVA matrix for the enhancement of its mechanical and thermal properties. The synthesized NCs were studied by Fourier transform infrared and X-ray diffraction spectroscopy analysis. The surface topography and morphology of the NCs were studied by atomic force microscopy techniques, field emission scanning electron microscopy and transmission electron microscopy. The micrographs demonstrated that the nanofillers were homogeneously dispersed in the PVA matrix. The thermo gravimetric analysis curves indicated that the thermal decomposition of the PVA/PAI-SiO₂ NC films shifted toward higher temperature in comparison with the pure PVA. The effect of nanofiller on the mechanical properties of NC films was also explored.     

A simple and environmentally friendly method for surface modification of ZrO2 nanoparticles by biosafe citric acid as well as ascorbic acid (vitamin C) and its application for the preparation of poly(vinyl chloride) nanocomposite films

In this investigation, poly(vinyl chloride) (PVC) as one of the most important thermoplastic polymer was combined with different concentrations (4, 8, and 12 wt%) of ZrO₂ nanoparticles (NPs) with the purpose of preparing novel nanocomposites (NCs). To prevent aggregation and obtain homogeneous dispersion of the NPs in the polymer matrix, surface modification of ZrO₂ was performed by biosafe, biodegradable as well as biocompatible modifiers such as citric acid and ascorbic acid (vitamin C) due to their ability to form chelates with metal oxides. The effect of modified ZrO₂ on the properties of the PVC was studied by different techniques. The field emission scanning electron microscopy and transmission electron microscopy results indicated that the modified NPs were dispersed homogeneously in the polymer matrix. UV–Vis spectroscopy was used to study optical behaviors of the obtained NCs. Thermogravimetric analysis indicated that the thermal stability of the polymer was enhanced after incorporation with NPs. Finally, mechanical test was revealed that the NC films were more flexible when compared with the neat polymer. POLYM. COMPOS., 38:1756–1765, 2017. © 2015 Society of Plastics Engineers     

A straightforward preparation and characterization of novel poly(vinyl alcohol)/organoclay/silver tricomponent nanocomposite films

In the present investigation, novel poly(vinyl alcohol)/organoclay/silver (PVA/OMMT/Ag) tricomponent nanocomposite (NC) films with different compositions were prepared by solution intercalation method under ultrasonic irradiation process. The NC films were obtained by mixing a colloidal solution consisting of Ag nanoparticles (NPs) (3, 5, 7 and 9 wt%) with a water solution of PVA and OMMT (10 wt%) via solution casting method. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis (TGA) were utilized to characterize the morphology and properties of the PVA/OMMT/Ag NC films. TGA confirmed that the heat stability of the nanocomposite was improved. The enhancement in the thermal properties of the hybrid materials was due to strong hydrogen bonding between OH groups of PVA, free acid functionalized groups of OMMT, and the Ag NPs. SEM and TEM results also showed that the OMMT and Ag NPs were dispersed homogeneously in the PVA matrix on nanoscale.     

The synthesis of poly(vinyl chloride) nanocomposite films containing ZrO2 nanoparticles modified with vitamin B1 with the aim of improving the mechanical,thermal and optical properties

In the present investigation, solution casting method was used for the preparation of nanocomposite (NC) films. At first, the surface of ZrO₂ nanoparticles (NPs) was modified with vitamin B₁ (VB₁) as a bioactive coupling agent to achieve a better dispersion and compatibility of NPs within the poly(vinyl chloride) (PVC) matrix. The grafting of modifier on the surface of ZrO₂ was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA). Finally, the resulting modified ZrO₂ (ZrO₂–VB₁), was used as a nano-filler and incorporated into the PVC matrix to improve its mechanical and thermal properties. These processes were carried out under ultrasonic irradiation conditions, which is an economical and eco-friendly method. The effect of ZrO₂–VB₁ on the properties and morphology of the PVC matrix was characterized by various techniques. Field emission scanning electron microscopy and transmission electron microscopy analyses showed a good dispersion of fillers into the PVC matrix with the average diameter of 37–40 nm. UV–Vis spectroscopy was used to study optical behavior of the obtained NC films. TGA analysis has con?rmed the presence of about 7 wt% VB₁ on the surface of ZrO₂. Also, the data indicated that the thermal and mechanical properties of the NC films were enhanced.     

Preparation and characterization of reinforced poly(vinyl alcohol) films by a nanostructured,chiral, L-leucine based poly(amide-imide)/ZrO2 nanocomposite through a green method

In the present investigation, at first, the surface of ZrO₂ nanoparticles was modified with a bioactive and biocompatible diacid based on leucine amino acid as a coupling agent. The grafting of diacid on the surface of ZrO₂ was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then, the synthesis of poly(amide-imide)/ZrO₂ nanocomposite (PAI/ZrO₂ NC) was performed through ultrasonic technique. The obtained NCs demonstrated good thermal stability. Field emission scanning electron microscopy and transmission electron microscopy analysis showed that the average diameter of NP was around 15–20 nm. Finally, the resulting NC, was used as a nano-filler and was incorporated into the poly(vinyl alcohol) (PVA) in order to improve its mechanical and thermal properties. The PVA/PAI–ZrO₂ NC films were characterized by different techniques. The data indicated that the thermal and mechanical properties of the PVA/PAI–ZrO₂ NC were enhanced. It was attributed to the good dispersion of filler into the PVA matrix as a result of hydrogen bonding.     

A facile and green method for the production of novel and potentially biocompatible poly(amide-imide)/ZrO2–poly(vinyl alcohol) nanocomposites containing trimellitylimido-l-leucine linkages

We have reported the synthesis of nanocomposites (NCs) based on chiral poly(amide-imide) (PAI) and modified zirconium nanoparticles (ZrO₂ NPs) with poly(vinyl alcohol) (PVA). The optically active PAI was prepared under the green condition via the direct polycondensation of biocompatible trimellitylimido-l-leucine diacid and 4,4′-diaminediphenylsulfone in the presence of tetrabutylammonium bromide and triphenyl phosphite as the green solvent and the activating agents. NPs, due to a high surface to volume ratio, have a great tendency to agglomerate in the polymer matrix. So, at first, the surface of ZrO₂ NPs was modified with the PVA as the biodegradable and biocompatible polymer. Afterward, the modified NPs were added into the PAI matrix in the ethanol solution under ultrasonic irradiations. The obtained PAI/ZrO₂–PVA NCs (PZ–PNC)s were characterized by various techniques. The Fourier transform infrared proved the formation of PZ–PNCs. Field emission-scanning electron microscopy exhibited that ZrO₂ NPs had good dispersion in the PAI matrix, and transmission electron microscopy indicated that ZrO₂ NPs were coated by a nanometer-thick layer of PVA that was about 10 nm. X-ray diffraction analysis showed that the ZrO₂ NPs retained their crystalline structure after they were added in the PAI matrix. Thermogravimetric analysis illustrated that the prepared PZ–PNCs had a better thermal stability than the neat PAI.     

Poly(vinyl alcohol)/CaCO3‐diacid nanocomposite: Investigation of physical and wetting properties and application in heavy metal adsorption

Poly(vinyl alcohol) (PVA) nanocomposite and modified CaCO₃ nanoparticles (NPs) were fabricated by ultrasound agitation method with particle content altering from 3, 5, and 8 wt %. The CaCO₃ surface was successfully treated by 10 wt % of bioactive dicarboxylic acid (DA). The influences of loading modified NPs on the thermal, mechanical, adsorption, contact angle, and physical properties of the poly(vinyl alcohol) nanocomposite films were thoroughly studied. The results showed that incorporation of modified CaCO₃ into the PVA matrix had better performance than the pure PVA. Meanwhile, tensile strength, Young's modulus, and thermal stability are enhanced from 33.36 MPa, 1.26 GPs, and 242.918C (neat PVA) to 81.7 MPa, 4.81 GPa, and 312.95 °C (PVA/CaCO₃‐DA NC 5 wt %), respectively. Also, the adsorption capacity of the PVA/CaCO₃‐DA NCs 5 and 8 wt % revealed that the NC films could act as an appropriate absorbent for the removal of Cd(II) ions with maximum adsorption capacity of about 20.70 and 25.19 mg g^?1 for Cd(II), respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45414.     

Thermal and morphology characterization study of bio‐active poly(amide‐imide)‐based nanocomposites reinforced with modified SiO2 nanoparticle with poly(vinyl alcohol)

Among the nanoparticles (NPs), the amorphous SiO₂ NPs are very useable, because of their important characteristics for different applications, such as mechanical performance, thermal properties, and biodegradability effects. For this manifest features SiO₂ NPs were used as filler in this study. Firstly, these NPs were modified with poly(vinyl alcohol) (PVA). Then, the poly(amide‐imide) (PAI) was synthesized from reaction between N‐trimellitylimido‐l ‐methionine and 4,4′‐diaminodiphenylether in the presence of ionic liquid and triphenyl phosphite. Next, the modified SiO₂ NPs with PVA (SiO₂‐PVA) were incorporated into the PAI matrix for the preparation of PAI‐SiO₂‐PVA nanocomposites (PSiPNs). Finally, the resulting SiO₂‐PVA and PSiPNs were characterized by different analyses like field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and thermogravimetric analysis (TGA). TGA showed high thermal stability of the obtained PSiPNs compared to the pure PAI. POLYM. COMPOS. 37:1231–1237, 2016. © 2014 Society of Plastics Engineers     

An Efficient Preparation and Characterization of Nanocomposite Films Based on Poly(vinyl chloride) and Modified ZnO Quantum Dot with an Optically Active Diacid Containing Amino Acid as Coupling Agent

The nanocomposites were manufactured by the incorporation of modified ZnO into the poly(vinyl chloride). ZnO nanoparticles were modified with diacid containing alanine amino acid. Ultrasonic irradiation was used for all process. The PVC/ZnO@DA nanocomposites were investigated by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV–visible spectroscopy, thermogravimetric, and mechanical analysis. Results showed the uniform dispersion of particles in the polymer matrix and ZnO@DA nanoparticles in quantum dot size. The optical properties of PVC were affected by the incorporation of modified quantum dot ZnO; also mechanical properties of PVC/ZnO@DA nanocomposites were improved.     

Surface treatment of plasticized poly(vinyl chloride) to prevent plasticizer migration

In this investigation, plasticized poly(vinyl chloride) (PVC) was treated with poly(azido acrylate)s to prevent plasticizer migration. This was achieved by modification of PVC sheets with poly(azido acrylate)s in a dichloromethane solution followed by irradiation under UV light. The surface‐modified PVC sheets with poly (azido acrylate)s were characterized with Fourier transform infrared spectroscopy and scanning electron microscopy analyses. The migration of the plasticizer was prevented to a large extent from modified PVC in comparison with unmodified PVC. The amount of plasticizer migration with respect to the irradiation time, incubation time, and number of dipping times was evaluated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Novel ternary poly(vinyl pyrrolidone)/poly(amide-imide)/ZnO nanocomposite: Synthesis,characterization, thermal and optical performance

The present work describes the synthesis and properties of polymer composites based on poly(vinyl pyrrolidone) (PVP) as polymer shell and poly(amide-imide)(PAI)/ZnO nanocomposite (ZNC) as efficient filler. At first, the alanine amino acid containing dicarboxylic acid was grafted on the surface of ZnO NPs. Then, modified ZnO (12 wt%) was incorporated into the PAI matrix under ultrasonic irradiations. The obtained hybrid ZNC showed high thermal stability and the size of the NPs in the TEM image of ZNC was about 31 nm. Secondly, PVP NCs with different ZNC loadings such as 2, 4 and 6 wt% were prepared via ultrasonication. Transmission electron microscopy (TEM) observations showed that the ZnO NPs were uniformly and highly dispersed in the PVP matrix. The UV–vis results exposed that the high UV-shielding efficiency of the obtained composites. Thermal analysis represented that the onset decomposition temperatures of the obtained PVPNCs had remarkable increasing in compared to the neat PVP due to the presence of both ZnO NPs and PAI.     

Surface coating of α-Al2O3 nanoparticles with poly(vinyl alcohol) as biocompatible coupling agent for improving properties of bio-active poly(amide-imide) based nanocomposites having l-phenylalanine linkages

Nanocomposites (NCs) containing metal oxide nanoparticles (NPs) as fillers are used in a wide range of applications and in various fields. Poly(vinyl alcohol) (PVA) is an attractive polymer because of its many desirable applications and characteristics. In this investigation, at first, the surface of alumina (α-Al₂O₃) NPs was modified with PVA as a biocompatible modifier. Then, the optically active poly(amide-imide) (PAI) nanostructure was prepared by using molten tetrabutylammonium bromide as a molten ionic liquid and triphenyl phosphite as the condensing agent. Finally, the modified α-Al₂O₃ (α-Al₂O₃-PVA) NPs were incorporated into the PAI matrix for the preparation of PAI/Al₂O₃-PVA NCs (PAPNCs). To investigate effect and nature of coating on the surface of the α-Al₂O₃ NPs and preparation of PAPNCs, the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The surface morphology examination demonstrated the monodispersed characteristics of α-Al₂O₃ NPs after surface modification with the PVA and incorporation into the PAI matrix.     

Green Route for the Synthesis of Alanine-based Poly(amide-imide) Nanocomposites Reinforced with the Modified ZnO by Poly(vinyl alcohol) as a Biocompatible Coupling Agent

The objective of this article was fabrication and characterization of novel optically active poly(amide-imide)/zinc oxide nanocomposites with different modified ZnO nanoparticle contents under ultrasonic irradiation technique. For better dispersion of ZnO nanoparticles in a polymer matrix, their surface was modified with poly(vinyl alcohol) as a coupling agent. Effects of poly(vinyl alcohol) modifier on dispersity of nanoparticles, morphological structures, and thermal stability of the obtained nanoparticles were studied by several techniques. According to the transmission electron microscopy images of the nanocomposite, the average diameter of particles was around 7–15 nm in the poly(amide-imide).     

Investigation of thermal,mechanical and electrochemical properties of nanocomposites based on CuO modified poly(vinyl chloride)/poly(methyl methacrylate) blend

The preparation of binary polymer blend nanocomposites with different nanomaterials is a relatively new approach to achieve desired physical, thermal, mechanical, and electrochemical properties because it has the collective effects of both polymer blending and fillers. Transition metal oxides constitute a large class among those fillers because the precursors for metal oxides are abundantly available. However, very few studies have been accomplished on incorporating transition metal oxides into binary polymer blends. In this project, cuprous oxide (CuO) nanoparticles (NPs) with a crystallite size of 24.95 nm were incorporated into poly(vinyl chloride)/poly(methyl methacrylate) (PVC/PMMA) blend, and thin films of the nanocomposites were obtained through a solution casting technique. Scanning electron microscopy, X‐ray diffraction, universal testing machine testing, thermogravimetric analysis, and cyclic voltammetry were used to study morphological, crystalline, mechanical, thermal, and electrochemical properties of the nanocomposites. Scanning electron micrographs showed that the blend was completely miscible and CuO NPs were well dispersed within the matrix. Mechanical properties greatly improved with each wt% addition of CuO NPs. Thermogravimetric analysis thermograms revealed a two‐stage degradation for neat PVC/PMMA blend and CuO/PVC/PMMA. Cyclic voltammetry results indicated a free electron transfer in neat blend that further improved with the incorporation of increasing percentage of CuO NPs. J. VINYL ADDIT. TECHNOL., 23:80–85, 2017. © 2015 Society of Plastics Engineers     

Dispersion of chiral amino acid organomodified Cloisite Na in poly(vinyl alcohol) matrix for designing of novel bionanocomposite films

In this study the inorganic nanolayers of Cloisite Na⁺ was modified with ammonium salt of l-valine amino acid (Val) and then it was dispersed in poly(vinyl alcohol) (PVA) matrix. The PVA/Cloisite Na⁺/Val bionanocomposites (BNC)s were prepared by solution intercalation technique using ultrasonic irradiation. The reaction between this novel organically modified Cloisite Na⁺ and PVA occurred by the hydrogen bonding and hydrophobic interactions. The basal spacing of the Cloisite Na⁺/Val was studied by X-ray diffraction. The thermal stability and optical clarity of PVA and PVA/Cloisite Na⁺/Val are also studied by thermogravimetric analysis (TGA) and UV–visible transmission spectra, respectively. TGA results show that using Cloisite Na⁺/Val in the PVA matrix improved the thermal stability property of the resulting BNC films. The morphological image of synthesized materials was studied by scanning electron microscopy, and transmission electron microscopy. The nanocomposite structure study specified a coexistence of exfoliated and intercalated Cloisite Na⁺/Val layers in the PVA matrix.     

The thermal,optical, flame retardant,and morphological consequence of embedding diacid‐capped ZnO into the recycled PET matrix

We extended our work to a fast and facile nanocomposites (NCs) manufacturing by incorporation of ZnO nanoparticles (NPs) on to a recycled poly(ethylene terephthalate) PET as a polymer matrix prepared by a dissolution/reprecipitation method. The surface of ZnO NPs was functionalized with synthesized optically active diacid containing alanine amino acid. Organo‐modified NPs which provided using solution blending technique through ultrasonic irradiation, were embedded into recycled PET. PET@ZnO/DA NCs containing different loadings of functionalized NPs (1, 3, 5 wt %) were investigated by thermal gravimetric analysis, field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy and UV–visible spectroscopy. Morphological studies revealed uniformly dispersed ZnO/DA NPs in the polymer matrix. The crystalline nature of PET slightly improved as a function of the NPs concentration. Char yield in TGA and LOI values indicated that the obtained NCs were capable of exhibiting flame retardant properties. The NCs were found to exhibit more absorbance in the UV and visible region in compare to the neat PET. The effect of ultrasonication in different solvent on the morphology of the recycled polymer particle was also studied. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43433.     

Effect of postcrosslinking modification with glutaraldehyde on the properties of thermoplastic starch/poly(vinyl alcohol) blend films

Thermoplastic starch (TPS)/poly(vinyl alcohol) (PVA) blend films were modified by crosslinking through soaking the films in glutaraldehyde aqueous solution and then heating in an oven. The effects of the concentration of the glutaraldehyde aqueous solution, soaking time, reaction temperature, and time on the crosslinking reaction were investigated. The moisture absorption and mechanical properties of the films were measured to characterize the influence of the crosslinking modification. It was found that the crosslinking modification significantly reduced the moisture sensitivity of the TPS/PVA blend films and increased the tensile strength and Young's modulus but decreased the elongation at break of the TPS/PVA blend films. The described method could be used for posttreating TPS/PVA‐based products to optimize their properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Characterization of polymeric biocomposite based on poly(vinyl alcohol) and poly(vinyl pyrrolidone)

Biocompatible and easily available materials from dairy production waste were used for modification of water‐soluble polymeric blends of Poly(vinyl alcohol) (PVA) and Poly(vinyl pyrrolidone) (PVP). The resulting biocomposites of PVA/PVP with various concentrations of lactose (L) or calcium lactate (CL) (0, 5, 15, 25, 35 wt%) were prepared by using a solvent cast technique and then characterized by optical microscopy, tensile test, water content determination, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy equipped by attenuated total reflectance device, and also tested for biodegradability. The films were transparent with a smooth surface. The results confirm that L and CL work as fillers in polymeric matrix. The tensile investigations showed enhanced Young's modulus (E) and tensile strength for low‐filled of composite materials (up to 5 wt% L and 15 wt% CL). The biodegradation test in aquatic conditions revealed improved biodegradability of modified blends. Both L and CL seem to be suitable for the modification of polymers, which can be convenient from economical and environmental point of view. POLYM. COMPOS., 27:147–152, 2006. © 2006 Society of Plastics Engineers.     

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

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

改性魔芋葡甘聚糖纳米晶对聚乙烯醇薄膜性能的影响

通过硫酸水解魔芋葡甘聚糖(KGM)得到魔芋葡甘聚糖纳米晶(NKGM),再表面接枝3-(三甲氧基硅丙基)十八烷基氯化铵,与壬基酚聚氧乙烯醚硫酸钠反应等过程得到改性KGM纳米晶类流体(NKGMf);然后采用溶液流延法制备了含NKGM和NKGMf的聚乙烯醇(PVA)薄膜;通过傅里叶变换红外光谱仪、透射电子显微镜、扫描电子显微镜、热失重分析仪、拉伸测试仪等对NKGM、NKGMf的结构和PVA薄膜的性能进行表征。结果表明,经改性后,NKGM的片状结构得以保留,在PVA基质中的分散性增加,薄膜的起始分解温度提高了23℃,拉伸强度提高了34.7%,其中,NKGMf的最佳含量为3%(质量分数,下同)。