MnSt2–kaolin–polyethylene film: An eco‐friendly polyethylene composite film and its thermo‐ and biodegradable research

A novel thermo‐ and biodegradable MnSt₂–kaolin–polyethylene (signed as MKPE) composite film was prepared through a melt blending technique. Manganese stearate and common kaolin were employed as thermo‐degradable additives and biodegradable promoter to improve the degradable efficiency of the waste PE. Thermo‐oxidative testing was carried out in an air oven maintained at 70°C simulating a compost temperature. The biodegradation of the aging films was also investigated by analysis of evolved carbon dioxide of films in aquatic test systems according to the International Standards ISO 14852 (1999). The composite film was characterized by electronic universal testing machine, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, attenuated total reflection‐flourier transformed infrared spectroscopy and thermo gravimetric analysis. These results showed that the MKPE film exhibited a high degree of susceptibility to thermo‐oxidation and biodegradation. After thermal aging for 30 days, the mechanical properties of MKPE films reduced quickly and oxygen groups were introduced into the polymer chains. The kaolin particles wrapped in polymers were exposed gradually because of the rupture of polymer chains by thermal aging. The biodegradation degree reached 24.26% after incubation in an aqueous medium for 60 days. A possible mechanism for thermal oxidative degradation and biodegradation was also discussed. POLYM. COMPOS., 36:939–945, 2015. © 2014 Society of Plastics Engineers     

Polyaniline modified mesoporous titanium dioxide that enhances oxo‐biodegradation of polyethylene films for agricultural plastic mulch application

Mesoporous titanium dioxide (M‐TiO₂) nanoparticles were successfully prepared followed by chemical modification with different contents of polyaniline (PANI/M‐TiO₂) and were used to accelerate the photo‐oxidation and biodegradation process of low‐density polyethylene (LDPE) film. The influence of these additives as a pro‐oxidant additive on the accelerated degradation of LDPE was investigated by photocatalytic oxidation under UV light irradiation and biodegradation with fungal strains. It was found that the as‐prepared PANI modified M‐TiO₂ particles exhibited an obvious light response from 400 to 800 nm which can improve the utilization of solar light. Compared with M‐TiO₂, PANI/M‐TiO₂ exhibited better photocatalytic performance when irradiated under UV light and the subsequent biodegradation efficiency was enhanced. Enhancement of the photocatalytic performance of PANI/M‐TiO₂ could be attributed to good dispersibility and compatibility of PANI/M‐TiO₂ in the LDPE matrix, a narrow band gap, effective separation of photogenerated electron–hole pairs and the chromophoric group of PANI which was used as a photosensitizer in the LDPE/PANI/M‐TiO₂ composite film. © 2019 Society of Chemical Industry     

Enhanced Solid‐Phase Photocatalytic Degradation Activity of a Poly(vinyl chloride)‐TiO2 Nanocomposite Film with Bismuth Oxyiodide

A new type of photodegradable poly(vinyl chloride)‐bismuth oxyiodide/TiO₂ (PVC‐BiOI/TiO₂) nanocomposite film was prepared by embedding a nano‐TiO₂ photocatalyst modified by BiOI into the commercial PVC plastic. The solid‐phase photocatalytic degradation behavior of the as‐prepared film was investigated in ambient air at room temperature under UV light irradiation, with the aid of UV‐Vis spectroscopy, weight loss monitoring, scanning electron microscopy, and FT‐IR spectroscopy. Compared to the PVC‐TiO₂ nanocomposite film, the PVC‐BiOI nanocomposite film and the pure PVC film, the PVC‐BiOI/TiO₂ nanocomposite film exhibited a higher photocatalytic degradation activity. The optimal mass ratio of BiOI to TiO₂ was found to be 0.75 %. The weight loss rate of the PVC‐BiOI/TiO₂ nanocomposite film reached 30.8 % after 336 h of irradiation, which is 1.5 times higher than that of the PVC‐TiO₂ nanocomposite film under identical conditions. The solid‐phase photocatalytic degradation mechanism of the nanocomposite films was briefly discussed.     

Solid‐phase photocatalytic degradation of polystyrene with TiO2/Fe(St)3 as catalyst

A novel photodegradable TiO₂‐Fe(St)₃‐polystyrene (TiO₂‐Fe(St)₃‐PS) nanocomposite was prepared by embedding TiO₂ and Fe(St)₃ into the commercial polystyrene. Ferric stearate was added into polymer as cocatalyst in order to improve the dispersion in polystyrene and photocatalytic efficiency of TiO₂ nanoparticles. Solid‐phase photocatalytic degradation of the TiO₂‐Fe(St)₃‐PS nanocomposite was carried out in an ambient air at room temperature under ultraviolet lamp. The properties of TiO₂‐Fe(St)₃‐PS composite film were compared with that of the pure PS film and the TiO₂‐PS composite film, through weight loss monitoring, scanning electron microscope, gel permeation chromatogram, and FTIR spectroscopy. The photodegradation efficiency of TiO₂‐Fe(St)₃‐PS composite film was higher than that of the pure PS film and the TiO₂‐PS composite film under the UV light irradiation. The average molecular weight (M_w) of TiO₂‐Fe(St)₃‐PS composite film decreased 63.08%, and the number of average molecular weight (M_n) decreased 79.49% after UV light irradiation for 480 h. Photo‐oxidation leads to an increase in the low molecular weight fraction by chain scission, thereby facilitating biodegradation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Photodegradation behavior of the polycarbonate/TiO2 composite films under the UV irradiation in ambient air condition

Photocatalytic degradation mechanism of the polycarbonate(PC)/TiO₂ composite films was studied under the ambient air condition in order to investigate the feasibility of the PC/TiO₂ composite as a photodegradable polymer. TiO₂ composition in the PC/TiO₂ composite was changed from 0 wt% to 4 wt%. Photodegradation behaviors of the composite films were compared with that of the pure PC films by performing the weight loss monitoring under UV irradiation, FTIR spectroscopy, color measurement analysis, SEM, and XPS analysis. The weight loss rate of the PC/TiO₂ composite film (33% weight loss after 300 h) with 4 wt% TiO₂ was twice as high as the pure PC films (14% weight loss after 300 h). The increase in the FTIR hydroxyl peak, and carbonyl peak intensity and the yellowing observation during the photodegradation were due to the formation of the photoproducts (aliphatic, aromatic chain‐ketones, aromatic, and OH radical) and the structural modification of polycarbonate. XPS analysis of composite film showed the photodegradation of the polymer surface and TiO₂ particles exposure on the surface of the composite films matrix. POLYM. COMPOS., 36:1462–1468, 2015. © 2014 Society of Plastics Engineers     

A Novel Way to Prepare Visible‐Light‐Responsive WO3/TiO2 Composite Film with High Porosity

Amorphous oxide film was prepared on the titanium substrate by plasma electrolytic oxidation (PEO) technology in acidic electrolyte consisting of tungstate and then subject to calcination in air. Films were characterized by scanning electron microscopy, energy dispersive X‐ray, X‐ray diffraction, X‐ray photoelectron spectroscopy, photoluminescence, and UV‐Vis DRS before and after calcination, respectively. Calcined film consisted of anatase and WO₃, showing more open structure compared with uncalcined film. Furthermore, the absorption edge of calcined film was shifted to visible light region and the recombination of photo‐induced carriers was inhibited effectively, resulting that WO₃/TiO₂ composite film produced by PEO technology and calcination should be effective as a visible‐light‐responsive photocatalyst.     

Semitransparent chitosan‐TiO2 nanotubes composite film for food package applications

Semitransparent composite films were prepared made from TiO₂ nanotubes in chitosan (CS) matrix. Hydrothermally synthesized titanium nanotubes (TiNTs) were dispersed in chitosan matrix in order to produce film‐forming solutions at 0.05 and 0.10% w/v. Structural, topological, optical and thermal properties of these films were evaluated. The antimicrobial activity of films against Salmonella enterica serovar Typhimurium, Escherichia coli (Gram‐negatives) and Staphylococcus aureus (Gram‐positive) was also investigated. Fourier transform infrared (FTIR) spectra showed effective site‐selective interactions between chitosan and TiNTs. TiNTs prevented the degradation of films, avoiding the oxidization of the glucosamine ring. Characterizing techniques such as, Scanning electron microscopy–energy dispersive spectroscopy (SEM‐EDS) line profile and atomic force microscopy (AFM) were used to examine the TiNTs dispersion within the film. The morphological analysis indicated that the TiNTs were well dispersed and became clustered proportionally to the weight percentage of TiNTs used in the composites. The UV‐Vis spectra showed that TiNTs increased the film absorption in the UV region and the light barrier properties of films remained stable over the storage period. Photoacoustic spectroscopy (PAS) was used to study these films, nondestructively for their thermal effusivity (e). The films were effective in reducing the microbial concentration in the liquid culture for all bacteria tested. The effectiveness was found to dependent on the bacterial strain and TiNTs content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Morphological and thermal properties of photodegradable biocomposite films

Biocomposites containing ultraviolet (UV) radiation absorbing inorganic nanofillers are of great interest in food packaging applications. The biodegradable polylactide (PLA) composite films were prepared by solvent casting method by incorporating 1 wt % of titanium dioxide (TiO₂) and Ag‐TiO₂ (silver nanoparticles decorated TiO₂) nanoparticles to impart the photodegradable properties. The films were exposed to UV radiation for different time periods and morphology of the composite films before and after UV exposure were investigated. The results showed that homogenous filler distribution was achieved in the case of Ag‐TiO₂ nanoparticles. The thermal properties and thermomechanical stability of the composite film containing Ag‐TiO₂ nanoparticles were found to be much higher than those of neat PLA and PLA/TiO₂ composite films. The scanning electron microscopy and X‐ray diffraction studies revealed that the photodegradability of PLA matrix was significantly improved in the presence of Ag‐TiO₂ nanoparticles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enhanced photochromism of heteropolyacid/polyvinylpyrolidone composite film by TiO2 doping

Novel composite film was synthesized by TiO₂ doping into phosphomolybdic acid (PMoA)/polyvinylpyrrolidone (PVP) system. The influence of TiO₂ doping on its microstructure and photochromic properties was investigated via atomic force microscopy, transmission electron microscope, Fourier transform infrared spectroscopy (FT‐IR), ultraviolet–visible spectra, and X‐ray photoelectron spectroscopy (XPS). After TiO₂ doping, the surface of TiO₂/PMoA/PVP composite film changed to rough from smooth, and the particle size significantly increased. The FT‐IR results verified that the basic structure of PMoA and PVP were not destroyed in the composite films. The non‐bonded interaction between the acid and polymer was strengthened by TiO₂ doping. Irradiated with UV light, composite films changed from colorless to blue. The TiO₂/PMoA/PVP composite film exhibited a strong photochromic effect and faster bleaching reaction than that of PMoA/PVP film. XPS results indicated that the amount of PMoA in photo‐reductive reaction was increased after TiO₂ doping, which resulted in the photochromic efficiencies enhanced. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41583.     

Ecofriendly behavior of host matrix in composites prepared from agro‐waste and polypropylene

Composites were prepared by two methods: (1) graft copolymerization (GFC) of isotactic polypropylene (PP) with coupling agent maleic anhydride (MAH), followed by esterification with coir fiber; (2) by direct reactive mixing (DFC) of PP, MAH, and peroxide with coir fiber in a minimax molder. These composites, after molding in films (5 × 5 cm, ～100 μm thickness) were examined for susceptibility to biological attack by measuring the percentage weight loss in compost up to 6 months, periodically, and fungal colonization on surface of the samples, when kept as sole carbon source for the growth of Aspergillus niger in culture medium up to 40 days. Photodegradation was evaluated by monitoring the variations in a Fourier transform infrared spectrum and crack formation after successive treatment with ultraviolet (UV) light (≥290 nm) for 0, 20, 50, and 100 h at 60°C in the presence of air. Specimens of virgin PP were taken as a reference during all periods of photo‐ and biodegradations. Significant consequences of the manner of composite preparation on photo/biodegradation were observed during the whole study. DFC samples degraded faster than GFC during the composting whereas, in culture, GFC was covered by fungi in a highly well‐uniform way. It is shown that photo‐oxidative aging directly enhanced the biodegradability of composites, as an increase in fungal growth rate and decrease in weight during composting was found. It was concluded that extent of compatibilization has a profound effect on photo/biodegradation of composite material; consequently, ester bonds were the main units during fungal consumption. Surface erosion was maximum in the case of 100 h UV‐treated GFC and minimum for unirradiated PP after culture exposure, as shown by scanning electron microscopy, which is due to the use of composite films as energy source by microbes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1009–1017, 2003     

Microwave photocatalysis III. Transition metal ion‐doped TiO2 thin films on mercury electrodeless discharge lamps: preparation,characterization and their effect on the photocatalytic degradation of mono‐chloroacetic acid and Rhodamine B

BACKGROUND: Mercury electrodeless discharge lamps (Hg‐EDLs) were used to generate UV radiation when exposed to a microwave field. EDLs were coated with doped TiO₂ in the form of thin films containing transition metal ions Mⁿ⁺ (M = Fe, Co, Ni, V, Cr, Mn, Zr, Ag). Photocatalytic degradation of mono‐chloroacetic acid (MCAA) to HCl, CO₂, and H₂O, and decomposition of Rhodamine B on the thin films were investigated in detail. RESULTS: Polycrystalline thin doped TiO₂ films were prepared by dip‐coating of EDL via a sol–gel method using titanium n‐butoxide, acetylacetone, and a transition metal acetylacetonate. The films were characterized by Raman spectroscopy, UV/Vis absorption spectroscopy, X‐ray photoelectron spectroscopy (XPS), electron microprobe analysis and by atomic force microscopy (AFM). The photocatalytic activity of doped TiO₂ films was monitored in the decomposition of Rhodamine B in water. Compared with the pure TiO₂ film, the UV/Vis spectra of V, Zr and Ag‐doped TiO₂ showed significant absorption in the visible region, and hence the photocatalytic degradation of MCAA had increased. The best apparent degradation rate constant (0.0125 min^?1), which was higher than that on the pure TiO₂ film by a factor of 1.7, was obtained with the Ag(3%)/TiO₂ photocatalyst. The effect of doping level of vanadium acetylacetonate on the photocatalytic efficiency of the V‐doped TiO₂ was determined. CONCLUSIONS: Transition metal ion‐doped TiO₂ thin films showed significant absorption in the visible region. The metal doped TiO₂ photocatalyst (with an appropriate amount of V, Zr and Ag) on the Hg‐EDLs increased the degradation efficiency of MCAA in a microwave field. Copyright © 2009 Society of Chemical Industry     

Visible light photocatalytic activity of TiO2/heat‐treated PVC film

BACKGROUND: Semiconductor TiO₂ has been investigated extensively due to its chemical stability, nontoxicity and inexpensiveness. However, the wide band gap of anatase TiO₂ (about 3.2 eV) only allows it to absorb UV light. TiO₂ nanoparticles modified by conditional conjugated polymers show excellent photocatalytic activity under visible light. However, these conjugated polymers are not only expensive, but also difficult to process. Polyvinyl chloride (PVC) was heat‐treated at high temperature to remove HCl and a C?C conjugated chain structure was obtained. When TiO₂ nanoparticles were dispersed into the conjugated polymer film derived from PVC, this composites film exhibited high visible light photocatalytic activity. RESULTS: The photocatalytic activity of TiO₂/heat‐treated PVC (HTPVC) film was investigated by degrading Rhodamine B (RhB) under visible light irradiation. The photodegradation of RhB follows apparent first‐order kinetics. The rate constants of RhB photodegradation in the presence of the TiO₂/HTPVC films with different mass content of TiO₂ are 16–56 and 4–14 times that obtained in the presence of the pure HTPVC and TiO₂/polymethyl methacrylate (PMMA) composite film, respectively. The TiO₂/HTPVC film showed excellent photocatalytic activity and stability after 10 cycles under visible light irradiation. CONCLUSION: TiO₂/HTPVC film exhibits high visible light photocatalytic activity and stability. Copyright © 2012 Society of Chemical Industry     

Synthesis,physical properties,and characterization of starch‐based blend films by adding nano‐sized TiO2/poly(methyl metacrylate‐co‐acrylamide)

The purpose of this study was to improve the physical properties and to expand the application range of starch‐based blend films added nano‐sized TiO₂/poly(methyl methacrylate‐co‐acrylamide) (PMMA‐co‐AM). Starch‐based blend films were prepared by using corn starch, polyvinyl alcohol (PVA), nano‐sized PMMA‐co‐AM, nano‐sized TiO₂/PMMA‐co‐AM particles, and additives, i.e., glycerol (GL) and citric acid (CA). Nano‐sized PMMA‐co‐AM was synthesized by emulsion polymerization and TiO₂ nanoparticles were also prepared by using sol–gel method. Nano‐sized TiO₂/PMMA‐co‐AM particles were synthesized by wet milling for 48 h. The morphology and crystallinity of TiO₂, nano‐sized PMMA‐co‐AM and TiO₂/PMMA‐co‐AM particles were investigated by using the scanning electron microscope (SEM) and X‐ray diffractometer (XRD). In addition, the functional groups of the TiO₂/PMMA‐co‐AM particles were characterized by IR spectrophotometry (FTIR). The physical properties such as tensile strength (TS), elongation at break (%E), degree of swelling (DS), and solubility (S) of starch‐based films were evaluated. It was found that the adding of nano‐sized particles can greatly improve the physical properties of the prepared films. The photocatalytic degradability of starch/PVA/nano‐sized TiO₂/PMMA‐co‐AM composite films was evaluated using methylene blue (MB) and acetaldehyde (ATA) as photodegradation target under UV and visible light. The degree of decomposition (C/C₀) of MB and ATA for the films containing TiO₂ and CA was 0.506 and 0.088 under UV light irradiation and 0.586 (MB) and 0.631 (ATA) under visible light irradiation, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Photobiodegradation of low‐density polyethylene/banana starch films

The effects of the starch content, photosensitizer content, and compatibilizer on the photobiodegradability of low‐density polyethylene (LDPE) and banana starch polymer blend films were investigated. The compatibilizer and photosensitizer used in the films were PE‐graft‐maleic anhydride (PE‐g‐MA) and benzophenone, respectively. Dried banana starch at 0–20% (w/w) of LDPE, benzophenone at 0–1% (w/w) of LDPE, and PE‐g‐MA at 10% (w/w) of banana starch were added to LDPE. The photodegradation of the blend films was performed with outdoor exposure. The progress of the photodegradation was followed by determining the carbonyl index derived from Fourier transform IR measurements and the changes in tensile properties. Biodegradation of the blend films was investigated by a soil burial test. The biodegradation process was followed by measuring the changes in the physical appearance, weight loss, and tensile properties of the films. The results showed that both photo‐ and biodegradation rates increased with increasing amounts of banana starch, whereas the tensile properties of the films decreased. The blends with higher amounts of benzophenone showed higher rates of photodegradation, although their biodegradation rates were reduced with an increase in benzophenone content. The addition of PE‐g‐MA into polymer blends led to an increase in the tensile properties whereas the photobiodegradation was slightly decreased compared to the films without PE‐g‐MA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2725–2736, 2006     

Preparation and characterization of a novel activated carbon‐supported N‐doped visible light response photocatalyst (TiO2−xNy/AC)

A photocatalyst, TiO_2?xN_y/AC (activated carbon (AC) supported N‐doped TiO₂), highly active in both the Vis and UV range, was prepared by calcination of the TiO₂ precursor prepared by acid‐catalyzed hydrolysis in an ammonia atmosphere. The powders were characterized by diffuse reflectance spectroscopy, scanning electron microscopy, X‐ray diffraction, N₂ adsorption, Fourier transform infrared spectroscopy and phenol degradation. The doped N in the TiO₂ crystal lattice creates an electron‐occupied intra‐band gap allowing electron‐hole pair generation under Vis irradiation (500–560 nm). The TiO_2?xN_y/AC exhibited high levels of activity and the same activity trends for phenol degradation under both Vis and UV irradiation: TiO_2?xN_y/AC calcined at 500 °C for 4 h exhibited the highest activity. The band‐gap level newly formed by doped N can act as a center for the photo‐generated holes and is beneficial for the UV activity enhancement. The performance of the prepared TiO_2?xN_y/AC photocatalyst revealed its practical potential in the field of solar photocatalytic degradation of aqueous contaminants. Copyright © 2007 Society of Chemical Industry     

Biodegradation of oxo‐biodegradable polyethylene

Biodegradation of polyethylene and oxo‐biodegradable polyethylene films was studied in this work. Abiotic oxidation, which is the first stage of oxo‐biodegradation, was carried out for a period corresponding to 4 years of thermo‐oxidation at composting temperatures. The oxidation was followed by biodegradation, which was achieved by inoculating the microorganism Pseudomonas aeruginosa on polyethylene film in mineral medium and monitoring its degradation. The changes in the molecular weight of polyethylene and the concentration of oxidation products were monitored by size exclusion chromatography and Fourier transform infrared (FTIR) spectroscopy, respectively. It has been found that the initial abiotic oxidation helps to reduce the molecular weight of oxo‐biodegradable polyethylene and form easily biodegradable product fractions. In the microbial degradation stage, P. aeruginosa is found to form biofilm on polymer film indicating its growth. Molecular weight distribution data for biodegraded oxo‐biodegradable polyethylene have shown that P. aeruginosa is able to utilize the low‐molecular weight fractions produced during oxidation. However, it is not able to perturb the whole of the polymer volume as indicated by the narrowing of the polymer molecular weight distribution curve toward higher molecular fractions. The decrease in the carbonyl index, which indicates the concentration of carbonyl compounds, with time also indicates the progress of biodegradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

High strength nanocomposite hydrogels with outstanding UV‐shielding property

A novel series of nanocomposite hydrogels (TAD gels) with high mechanical strength and excellent UV‐shielding property were prepared by in situ free‐radical copolymerization of acrylamide (AM) and N,N‐dimethylacrylamide (DMAA) in aqueous solutions of TiO₂ nanoparticles (TiO₂ NPs). It was found that the TiO₂ NPs were uniformly dispersed in the copolymer matrix and acted as inorganic crosslinking agents in TAD gels owing to their hydrogen bonding interactions with polymer chains. The TAD gels exhibited excellent mechanical properties such as large elongations at break, high elastic moduli, and ultimate stresses, all of these properties as well as swelling ratios of TAD gels could be easily controlled by changing the AM ratios and TiO₂ contents in the initial solutions. In addition, the TAD gels with low AM ratios could be prepared into thin films in a customized Teflon model and these films showed high transparency in visible light but could completely block the UV light with wavelength below 366 nm and prevent the methylene blue from degradation under UV irradiation. POLYM. COMPOS., 37:810–817, 2016. © 2014 Society of Plastics Engineers     

Effect of pro‐oxidants on biodegradation of polyethylene (LDPE) by indigenous fungal isolate,Aspergillus oryzae

Proxidant additives represent a promising solution to the problem of the environment contamination with polyethylene film litter. Pro‐oxidants accelerate photo‐ and thermo‐oxidation and consequent polymer chain cleavage rendering the product apparently more susceptible to biodegradation. In the present study, fungal strain, Aspergillus oryzae isolated from HDPE film (buried in soil for 3 months) utilized abiotically treated polyethylene (LDPE) as a sole carbon source and degraded it. Treatment with pro‐oxidant, manganese stearate followed by UV irradiation and incubation with A. oryzae resulted in maximum decrease in percentage of elongation and tensile strength by 62 and 51%, respectively, compared with other pro‐oxidant treated LDPE films which showed 45% (titanium stearate), 40% (iron stearate), and 39% (cobalt stearate) decrease in tensile strength. Fourier transform infrared (FTIR) analysis of proxidant treated LDPE films revealed generation of more number of carbonyl and carboxylic groups (1630–1840 cm⁻¹ and 1220–1340 cm⁻¹) compared with UV treated film. When these films were incubated with A. oryzae for 3 months complete degradation of carbonyl and carboxylic groups was achieved. Scanning electron microscopy of untreated and treated LDPE films also revealed that polymer has undergone degradation after abiotic and biotic treatments. This concludes proxidant treatment before UV irradiation accelerated photo‐oxidation of LDPE, caused functional groups to be generated in the polyethylene film and this resulted in biodegradation due to the consumption of carbonyl and carboxylic groups by A. oryzae which was evident by reduction in carbonyl peaks. Among the pro‐oxidants, manganese stearate treatment caused maximum degradation of polyethylene. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Recent progress in electrospinning TiO2 nanostructured photo‐anode of dye‐sensitized solar cells

The key to improving the performance of dye‐sensitized solar cells is the photo‐anode that has much dye adsorption and short optoelectronic transmission path. Electrospun TiO₂ films in photo‐anode have high specific surface area and meet the demand exactly. The article summarizes these efforts in TiO₂ photo‐anode improvement, including various morphology, different one‐dimensional and two‐dimensional composite structure, and varied element doped TiO₂ photo‐anode. Besides, the review makes comparison with these different TiO₂ photo‐anodes in photoelectric properties. The conclusions provide a clear guidance in design of morphology, structure, and doping, which is helpful for researcher to improve the performance of the anode and increase the photoelectric conversion efficiency especially those prepared using electrospinning. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45649.     

Morphologies and applied properties of free radical/cationic UV‐cured CPUA/TMPTMA/CER composite films

A UV‐cured composite film was prepared by free free‐radical photopolymerization from a blend containing oligomer cycloaliphatic polyurethane acrylate (CPUA) and reactive diluent trimethylolpropane trimethaacrylate (TMPTMA) with the same weight (coded as UT) in the presence of free free‐radical photoinitiator Irgacure 754. It was proved to be a homogeneous system featuring only one phase by means of scanning electron microscopy (SEM). Cycloaliphatic epoxy resin (CER) was introduced to enhance mechanical properties of the UV‐cured UT composite film in the presence of cationic photoinitiator Irgacure 250, and a series of UV‐cured CPUA/TMPTMA/CER composite films with different component ratios were prepared by free radical/cationic hybrid UV UV‐curing technique. Results of conversion curves, SEM, and Fourier‐ transform infrared spectroscopy illustrated that UT was cured faster than CER, leading to dynamically asymmetric photopolymerization‐induced phase ‐separation behaviors. The thermal and mechanical properties were evaluated via thermal degradation analysis, dynamic mechanical analysis, and stress–strain curves. Surface properties such as pencil hardness, pendulum hardness, shrinkage rate, contact angle, flexibility, and glossiness were also studied. All these measurements revealed that component ratios, intermolecular attractions, photopolymerization velocities, and viscosities had remarkably influenced on the morphologies and applied properties of UV‐cured composite films, and interpenetrating polymer network films had better comprehensive performances than other UV‐cured composite films with different microstructures. POLYM. COMPOS., 36:1177–1185, 2015. © 2014 Society of Plastics Engineers