Cellulose–Polyvinyl Alcohol–Nano-TiO2 Hybrid Nanocomposite: Thermal,Optical, and Antimicrobial Properties against Pathogenic Bacteria

Cellulose fiber-reinforced composite has received great attention due to the high strength, stiffness, biodegradability, and renewability of the excellent natural biomaterials. Cellulose nanofibers for the development of organic–inorganic hybrid composite is relatively new filed of research. Cellulose macro and nanofibers can be used as reinforcement in the hybrid composite because of improved mechanical, thermal, optical, electrical, morphological, and biological properties. The hybrid nanocomposites were synthesized by an in situ sol–gel process in the presence of coupling agent. The sol–gel process has definitely proven its potential by providing the synthesis of various functional organic–inorganic hybrid nanocomposites through an in situ sol–gel process. The hybrid nanocomposites have been prompted by the ability to control the morphology of final materials. The photoluminescence spectral studies indicate that the emission shifts toward higher wavelength (326–532?nm) accompanied by a reduction in impurity centers with increasing concentration of poly(vinyl alcohol)–TiO₂ and hybrid nanocomposite. The final nanostructured TiO₂ hybrid nanocomposites with particle size ranging from 0.32 to 20?nm were characterized by Field -emission transmission electron microscopy (FE-TEM) analysis. Furthermore, cellulose–poly(vinyl alcohol)–nano-TiO₂ hybrid composite was characterized by Fourier transform infrared, X-ray diffraction, UV, Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), FE-SEM–EDX, Field-emission scanning electron microscopy (FE-SEM), and FE-TEM analysis. The different analysis results of the hybrid composite indicate the optical transparency, optical properties, T_g, crystallinity, thermal stability, and controlled morphology of hybrid nanocrystalline composites. Finally, the cellulose–poly(vinyl alcohol)—nano-TiO₂ hybrid nanocomposites were tested against pathogens such as Gram-positive Bacteria Bacillus cereus and Gram-negative Escherichia coli for antimicrobial activity. These results show that the hybrid composite exhibited excellent antimicrobial properties against pathogens.     

Study on poly(propylene)/ammonium polyphosphate composites modified by ethylene‐1‐octene copolymer grafted with glycidyl methacrylate

The compatibilization effect of ethylene‐1‐octene copolymer grafted with glycidyl methacrylate (POE‐g‐GMA) as an interface compatibilizer on the mechanical and combustion properties, and the morphology and structures of the cross sections of ammonium polyphosphate (APP)–filled poly(propylene) (PP) were investigated by thermogravimetry, dynamic mechanical analysis, and differential scanning calorimetry. The results indicated that the toughness of the PP/APP composites increased rapidly with adding POE‐g‐GMA; the dynamic mechanical spectra revealed that the increase of the toughness was closely related to the peaks of loss modulus (E″) and mechanical loss (tan δ). The improvement of the dispersion of APP in the PP matrix was attributed to the addition of POE‐g‐GMA; it was found that the interfacial adhesion between the filler and matrix was enhanced when the grafting material was added to the composites. Under such circumstances, the ratio of char formation was increased when the PP composites were heated, although the content of flame retardant was not changed, so the flame retardance of the material was improved. The addition of POE‐g‐GMA increased the rate of crystallization. At the same time, the degree of crystallinity and the temperature at the beginning of crystallization were decreased, although exerting little influence on the melt behavior of the crystallization of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 412–419, 2004     

The viscoelastic properties of modified thermoplastic impregnated multiaxial aramid fabrics

This study reports the manufacture of new fabric forms from the preparation of hybrid laminated multiaxial composites with enhanced thermo‐mechanical properties. Thermal and dynamic mechanical analysis of polymer matrix films and fabricated hybrid composites were used to determine the optimal material composition and reinforcement content for composites with improved viscoelastic properties. The introduction of 5 wt% silica nanoparticles in a composite of p‐aramid–poly(vinyl butyral) led to significant improvements in the mechanical properties, and the addition of silane coupling agents yielded maximal values of the storage modulus for hybrid nanocomposites. The introduction of silane led to a better dispersion and deagglomeration of SiO₂ particles, and to the formation of chemical bonds between organic and inorganic constituents, or p‐aramid–poly(vinyl butyral) composites. In this way, the mobility of macromolecules was reduced, which can be seen from the decreasing value of damping factor for the p‐aramid–poly(vinyl butyral) composite. Analysis of the glass transition temperature of the composite with amino‐functionalized silica nanoparticles revealed improved thermal stability in addition to the aforementioned mechanical properties of the tested materials. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

Influence of interfacial adhesion on the structural and mechanical behavior of PP‐banana/glass hybrid composites

Hybrid composites of polypropylene (PP), reinforced with short banana and glass fibers were fabricated using Haake torque rheocord followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both fibers into PP matrix resulted in increase of tensile strength, flexural strength, and impact strength upto 30 wt% with an optimum strength observed at 2 wt% MAPP treated 15 wt% banana and 15 wt% glass fiber. The rate of water absorption for the hybrid composites was decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has been analyzed to investigate the interfacial properties. An increase in storage modulus (E′) of the treated‐composite indicates higher stiffness. The loss tangent (tan δ) spectra confirms a strong influence of fiber loading and coupling agent concentration on the α and β relaxation process of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out through differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA), indicated an increase in the crystallization temperature and thermal stability of PP with the incorporation of MAPP‐treated banana and glass fiber. POLYM. COMPOS., 31:1247–1257, 2010. © 2009 Society of Plastics Engineers     

Poly(propylene) composite with hybrid nanofiller: Dynamic properties

Mechanical, impact, and relaxation properties of in situ synthesized carbon nanotubes‐polyaniline (CNT‐PANi) hybrid nanoparticle‐filled poly(propylene) (PP) composites with or without an amphiphilic dispersing agent were investigated using tensile testing, notched Charpy impact testing, and dynamical mechanical testing methods. The reference material was MWCNT filled PP composite. Ethyl gallate (EG) was the dispersing agent which realizes high conductivity in PP composites with hybrid filler. Measured properties showed quite similar behavior of CNT‐PANi hybrid and neat CNT filled composites. Addition of 20% EG in PP did not cause essential differences compared to the neat PP. When the dispersing agent was added in filler containing PP composites, remarkable effects were observed, especially in PP‐hybrid composites. Mechanically, these materials had improved tensile properties, but they were brittle compared to the materials without dispersing agent. Dynamic mechanical analysis showed improvement in storage modulus, and in loss modulus the α transition was well observable. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation of polyethylene‐octene elastomer/clay nanocomposite and microcellular foam processed in supercritical carbon dioxide

Polyethylene‐octene elastomer (POE)/organoclay nanocomposite was prepared by melt mixing of the POE with an organoclay (Cloisite 20A) in an internal mixer, using poly[ethylene‐co‐(methyl acrylate)‐co‐(glycidyl methacrylate)] copolymer (E‐MG‐GMA) as a compatibilizer. X‐ray diffraction and transmission electron microscopy analysis revealed that an intercalated nanocomposite was formed and the silicate layers of the clay were uniformly dispersed at a nanometre scale in the POE matrix. The nanocomposite exhibited greatly enhanced tensile and dynamic mechanical properties compared with the POE/clay composite without the compatibilizer. The POE/E‐MA‐GMA/clay nanocomposite was used to produce foams by a batch process in an autoclave, with supercritical carbon dioxide as a foaming agent. The nanocomposite produced a microcellular foam with average cell size as small as 3.4 µm and cell density as high as 2 × 10¹¹ cells cm^?3. Copyright © 2005 Society of Chemical Industry     

Influence of Starch Oxidization and Modification on Interfacial Interaction,Rheological Behavior,and Properties of Poly(Propylene Carbonate)/Starch Blends

The enhanced maleic anhydride-end-capped poly(propylene carbonate)/starch blends were prepared through starch oxidization and modification with a coupling agent, aluminic ester. The interfacial interaction, rheological behavior, and properties of blends were investigated through Fourier transform infrared spectroscopy, rheological measurement, mechanical property test, differential scanning calorimetric, thermogravimetric analysis, and moisture absorption test. The results show that hydrogen-bonding interaction is formed between poly(propylene carbonate) and starch, which makes the tensile strength of maleic anhydride-end-capped poly(propylene carbonate)/starch blends improved significantly. The glass transition temperature (T_g) of blends is increased when coupling agent is induced into polymer system. When increasing the content of starch modified with coupling agent from 10 to 30%, T_g values for composites increased from 30.5 to 32.8°C. Thermogravimetric analysis results show that oxidation of starch can improve the thermal stability and modification of starch through aluminic ester that can further increase the thermal stability of maleic anhydride-end-capped poly(propylene carbonate)/starch blends. Oxidation of starch has no significant effect on moisture absorption for poly(propylene carbonate)/starch blends.     

Adsorption of IgG on spacer‐arm and L‐arginine ligand attached poly(GMA/MMA/EGDMA) beads

This work presents data on human immunoglobulin G (HIgG) adsorption onto L ‐arginine ligand attached poly(GMA/MMA/EGDMA)‐based affinity beads which were synthesized from methyl methacrylate (MMA) and glycidiyl methacrylate (GMA) in the presence of a crosslinker (i.e., ethylene glycol dimethacrylate; EGDMA) by suspension polymerization. The epoxy groups of the poly(GMA/MMA/EGDMA) beads were converted into amino groups after reaction with ammonia or 1,6‐diaminohexane (i.e., spacer‐arm). With L ‐arginine as a ligand, it was covalently immobilized on the aminated (poly(GMA/MMA/EGDMA)‐ AA) and/or the spacer‐arm attached (poly(GMA/MMA/EGDMA)‐SA) beads, using glutaric dialdehyde as a coupling agent. Both affinity poly(GMA/MMA/EGDMA)‐based beads were used in HIgG adsorption/desorption studies under defined pH, ionic strength, or temperature conditions in a batch reactor, using acid‐treated poly(GMA/MMA/EGDMA) beads as a control system. The poly(GMA/MMA/EGDMA)‐SA affinity beads resulted in an increase in the adsorption capacity to HIgG compared with the aminated counterpart (i.e., poly(GMA/MMA/EGDMA)‐AA). The maximum adsorption capacities of the poly(GMA/MMA/EGDMA)‐AA and poly(GMA/MMA/EGDMA)‐SA affinity beads were found to be 112.36 and 142 mg g^?1, and the affinity constants (K_d), evaluated by the Langmuir model, were 2.48 × 10^?7 and 6.98 × 10^?7M, respectively. Adsorption capacities of the poly(GMA/MMA/EGDMA)‐AA and poly(GMA/MMA/EGDMA)‐SA were decreased with HIgG by increasing the ionic strength adjusted with NaCl. Adsorption kinetic of HIgG onto both affinity adsorbents was analyzed with first‐ and second‐order kinetic equations. The first‐order equation fitted well with the experimental data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 672–679, 2007     

Preparation and mechanical properties of poly(vinyl chloride)/bamboo flour composites with a novel block copolymer as a coupling agent

To improve the interfacial adhesion between poly(vinyl chloride) (PVC) and bamboo flour in PVC/bamboo flour composites, a novel coupling agent, poly(styrene‐co‐maleic anhydride)‐block‐poly(styrene‐co‐acrylonitrile) {P[(SMA)‐b‐(SAN)]}, was synthesized through living free‐radical polymerization in a one‐pot reaction. P[(SMA)‐b‐(SAN)] was synthesized by a nitroxide‐mediated polymerization technique in the presence of 2,2,6,6‐tetramethylpiperidin‐l‐oxyl with azobisisobutyronitrile. The conversion of maleic anhydride (>99%) and styrene (>65%) was relatively high and yielded P[(SMA)‐b‐(SAN)] with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight <1.38). PVC was blended with bamboo flours in the presence of the synthesized coupling agent with a two‐roll mill. P[(SMA)‐b‐(SAN)] was added to the PVC matrix at a concentration of 55 or 20 wt %. As the content of P[(SMA)‐b‐(SAN)] in the wood–polymer composite increased, improved morphological and mechanical behaviors were observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Gloss reduction and morphological properties of polycarbonate and poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) blends with SAN‐co‐GMA as a reactive compatibilizer

The gloss properties of the polycarbonate (PC)/poly(methyl methacrylate‐acrylonitrile‐butadiene‐styrene) (MABS) blend with styrene‐acrylonitrile‐co‐glycidyl methacrylate (SAN‐co‐GMA) as a compatibilizing agent were investigated. For the PC/poly(MABS)/SAN‐co‐GMA (65/15/20, wt %) blend surface, the reduction of gloss level was observed most significantly when the GMA content was 0.1 wt %, compared with the blends with 0.05 wt % GMA or without GMA content. The gloss level of the PC/poly(MABS)/SAN‐co‐GMA (0.1 wt % GMA) blend surface was observed to be 35, which showed 65% lower than the PC/poly(MABS)/SAN‐co‐GMA blend without GMA content. The gloss reduction was most probably caused by the insoluble fractions of the PC/poly(MABS)/SAN‐co‐GMA blend that were formed by the reaction between the carboxylic acid group in poly(MABS) and epoxy group in SAN‐co‐GMA. The results of optical and transmission electron microscope analysis, spectroscopy study, and rheological properties supported the formation of insoluble structure of the PC/poly(MABS)/SAN‐co‐GMA blend when the GMA content was 0.1 wt %. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46450.     

Characterization of poly(2-hydroxyethyl methacrylate-silica) hybrid materials with different silica contents

Poly(2-hydroxyethyl methacrylate-silica) hybrid materials with significantly lower volume shrinkage were synthesized by using acid-catalyzed sol-gel reactions of tetraethyl orthosilicate and free radical polymerization of 2-hydroxyethyl methacrylate (HEMA). The mechanical, thermal, and optical properties and internal porosities of the poly(HEMA-silica) hybrids with different silica contents (e.g., 15, 25 and 30 wt%) were evaluated with the use of nanoindentation, microscratch, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, UV-vis spectrophotometer and N₂ adsorption-desorption method. A silica percolation threshold was found at around 20-25 wt%, beyond which a marked increase in the poly(HEMA-silica) hybrid hardness and modulus was observed as compared to pure poly(HEMA). Nanoindentation and scratch testing measurements also for the first time were introduced in characterizing poly(HEMA-silica) hybrid materials.     

Human serum albumin adsorption on poly[(glycidyl methacrylate)‐co‐(methyl methacrylate)] beads modified with a spacer‐arm‐attached L‐histidine ligand

Poly(GMA/MMA) beads were synthesized from glycidyl methacrylate (GMA) and methyl methacrylate (MMA) in the presence of a cross‐linker (i.e. ethyleneglycol dimethacrylate) (EGDMA) via suspension polymerization. The epoxy groups of the poly(GMA/MMA) beads were converted into amino groups with either ammonia or 1,6‐diaminohexane (i.e. spacer‐arm). An L ‐histidine ligand was then covalently immobilized on the aminated (poly(GMA/MMA)‐AH) and/or the spacer‐arm attached (poly(GMA/MMA)‐SAH) beads using glutaric dialdehyde as a coupling agent. Both affinity adsorbents were used in human serum albumin (HSA) adsorption/desorption studies under defined pH, ionic strength or temperature conditions in a batch reactor. The spacer‐arm attached affinity adsorbent resulted in an increase in the adsorption capacity to HSA when compared to the aminated counterpart (i.e. poly(GMA/MMA)‐AH). The maximum adsorption capacities of the affinity adsorbents were found to be significantly high, i.e. 43.7 and 80.2 mg g^?1 (of the beads), while the affinity constants, evaluated by the Langmuir model, were 3.96 × 10^?7 and 9.53 × 10^?7 mol L^?1 for poly(GMA/MMA)‐AH and poly(GMA/MMA)‐SAH, respectively. The adsorption capacities of the affinity adsorbents were decreased for HSA by increasing the ionic strength, adjusted with NaCl. The adsorption kinetics of HSA were analysed by using pseudo‐first and pseudo‐second‐order equations. The second‐order equation fitted well with the experimental data. Copyright © 2005 Society of Chemical Industry     

Preparation of poly(methyl methacrylate‐co‐maleic anhydride)/SiO2?TiO2 hybrid materials and their thermo‐ and photodegradation behaviors

The optically transparent poly(methyl methacrylate‐co‐maleic anhydride) P(MMA‐co‐MA)/SiO₂? TiO₂ hybrid materials were prepared using 3‐aminopropyl triethoxysilane as a coupling agent for organic and inorganic components. Real‐time FTIR was used to monitor the curing process of hybrid sol, indicating that imide group formation decreased with increasing titania content. scanning electron microscopy, atomic force microscopy, and differential scanning calorimetry results confirmed their homogeneous inorganic/organic network structures. TGA analysis showed that incorporated titania greatly prohibits the thermodegradation of hybrid films, especially at the content of 5.3 wt %, showing an increase of about 32.6°C at 5% loss temperature in air. The UV degradation behavior of P(MMA‐co‐MA) studied by quasi‐real‐time FTIR showed that TiO₂ incorporated in the hybrid network provides a photocatalytic effect rather than a UV‐shielding effect. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1714–1724, 2005     

Synthesis and characterization of dendritic poly(amidoamine)‐silica gel hybrids

Novel dendrimer‐silica gel hybrids were prepared from amino‐terminated poly(amidoamine) generation 3 (32 cascade) and its partly ester‐terminated derivatives with tetraethoxysilane in the presence of a coupling agent 3‐glycidoxypropyltrimethoxysilane by in situ sol‐gel process. The scanning electron micrograph spectra showed that these transparent hybrids have the nanocomposite structure. Their transparent and thermal properties were characterized by ultraviolet, thermogravimetric analysis. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2186–2190, 2000     

Modification and characterization of the poly(vinyl chloride)/thermoplastic polyurethane foam composite material

The polyvinyl chloride (PVC)/thermoplastic polyurethane (TPU) foam composite was modified by glycidyl methacrylate (GMA) innovative and prepared by sheet molding method with foaming agent azodicarbon amide (AC) and crosslinking agent bis‐tert‐butylperoxy diisopropylbenzene (BIPB). The properties of PVC/TPU foam composites effected by GMA content were investigated by the density, impact, tensile, and flexible test. The experiment indicated that with the addition of GMA, the impact strength tensile strength and flexible modulus were firstly rose to maximum at a fast rate and then decreased slightly. The properties significantly increased at a low content of modifier GMA. The results observed by differential scanning calorimetry indicated that new crosslinking network between PVC and TUP formed after the addition of GMA. The foam quality and cell morphology were studied by SEM and then statistics. With the addition of 0.6 phr BIPB and 0.5 phr GMA, the cell size of PVC/TPU composite is 80–130 μm and cell wall is 10–15 μm. Furthermore, the cells have more uniform distribution and fewer collapse when compared with the material without GMA. POLYM. COMPOS., 35:1716–1722, 2014. © 2013 Society of Plastics Engineers     

Micromechanical characterization of composite materials based on poly(styryl pyridine) thermoset resin

The purpose of this paper is to propose a micromechanical characterization of composite materials through measurement of the work-hardening rate K in the preyield stage during compression tests at constant strain-rate. This method belongs to a more general framework where the non-elastic deformation of glassy polymers is analyzed from a metallurgical point of view. The parameter K varies as the inverse of the nucleation rate of dislocations which are responsible for the non-elastic deformation. The method is used, here, to characterize a model composite material : PSP resin (poly(styryl pyridine)) filled with glass beads. K measurements show that introducing glass beads in the PSP resin enhances its ability to deform plastically, i.e. the presence of glass beads increases strongly the nucleation rate of dislocations. K-measurements and scanning electron microscopy investigations seem to show that the coupling agent A1100 is not appropriate to the PSP matrix.     

玻纤增强PPESK复合材料及其性能研究

以溶液共混-共沉淀的方式制备了玻纤增强含二氮杂萘联苯结构的聚醚砜酮(PPESK)复合材料；考察了两种长度的玻纤对GF／PPESK复合材料力学性能的影响，并以较长的玻纤为例，通过SEM对复合材料的形态进行观察，用DSC和TGA对其热性能进行分析，同时分析偶联剂在复合材料中的作用。结果表明：较长的玻纤更有利于提高复合材料的力学性能；当GF含量为20％时，两种GF／PPESK复合材料的力学性能都达到最大。偶联剂的加入对于改善玻纤与PPESK的界面粘结、提高玻纤对PPESK的增强效果具有重要作用。随着玻纤含量的增加，复合材料的玻璃化转变温度和热降解温度都不同程度地提高。     

Acrylonitrile–butadiene rubber functionalization for the toughening modification of recycled poly(ethylene terephthalate)

The incorporation of functionalized acrylonitrile–butadiene rubber (NBR) into recycled poly(ethylene terephthalate) (PET) was introduced as an effective route for modifying the properties of PET and as a new method for PET recycling as well. To achieve modified NBR, glycidyl methacrylate (GMA) was grafted onto NBR with optimized reactive mixing, in which the highest grafting degree and lowest gel content were generated. PET/NBR blends with and without GMA functionalization were produced by melt mixing, and the mechanical properties, dynamic mechanical thermal properties, and phase morphologies of the systems were determined and compared. We found that low amounts of peroxide initiator (dicumyl peroxide) and high levels of the GMA monomer in the presence of the styrene comonomer led to the maximum grafting degree and suppressed the competing rubber crosslinking and GMA homopolymerization reactions. The blend compatibility with PET determined from dynamic mechanical thermal analysis spectra and scanning electron microscopy images was greatly improved when the NBR‐grafted GMA was used instead of the neat NBR in the blend recipes. As a result, the rubber phase dispersed in the PET matrix more finely, and the impact strength of the blend advanced very significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40483.     

The single fiber composite test: A comparison of E‐glass fiber fragmentation data with statistical theories

Novel difunctional and tetra functional organically modified ceramics with methacrylate functional groups were developed from liquid precursors using the sol–gel process. These novel inorganic–organic hybrid materials were characterized using various techniques and used for the preparation of visible light cure dental restoratives, which have good mechanical properties and excellent surface hardness. Effect of cure time on vickers hardness of cured composite was measured, and compared with that of the bisphenol A glycidyl methacrylate (Bis GMA) based composite. Statistical evaluation using analysis of variance (single factor) showed a significant (P < 0.05) difference in diametral tensile strength and hardness with variation in inorganic content. Also a significantly improved hardness was obtained for the new organically modified ceramic composite compared with BisGMA based composite at all exposure time. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Environmental responses of poly(N‐isopropylacrylamide‐co‐glycidyl methacrylate derivatized dextran) hydrogels

A series of intelligent hydrogels (poly(NIPA‐co‐GMA‐Dex)) were synthesized by copolymerization of N‐isopropylacrylamide (NIPA) and glycidyl methacrylate derivatized dextran (GMA‐Dex) in aqueous solution with different ratios. Their swelling behaviors at different temperatures and in different pH and ionic strengths, and their mechanical properties were studied. It has found that poly(NIPA‐co‐GMA‐Dex) hydrogels are temperature‐, pH‐, and ionic strength‐sensitive associated with the roles of the component PNIPA and GMA‐Dex, respectively. Most significantly, poly (NIPA‐co‐GMA‐Dex) hydrogels exhibit simultaneously good swelling properties and mechanical properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2435–2439, 2005