Improvement of Physico-Mechanical Properties of Photo-Cured Chitosan Films with Ethylene Glycol Dimethacrylate and (2-Hydroxyethyl) Methacrylate

Chitosan, a natural polymer, was prepared by deacetylation of chitin which was obtained from dried prawn shell and was characterized. Thin chitosan film of chitosan was prepared by casting method from 0.2 % chitosan in 2 % acetic acid solution. Five formulations were developed with ethylene glycol dimethacrylate and (2-hydroxyethyl) methacrylate along with photo-initiator, Darocur-1664 (4 %). The chitosan film was soaked in the formulations at different soaking times and irradiated under UV-radiation at different intensities for the improvement of its physical and mechanical properties. The cured chitosan films were then subjected to various mechano-chemical tests like tensile strength, elongation at break, polymer loading, water absorption and gel content. The formulation containing 30 % ethylene glycol dimethacrylate and 66 % (2-hydroxyethyl) methacrylate showed the best performance at the 30th UV pass of UV-radiation for 3 min soaking time.     

Photodegradation of Poly(lactic acid) Stereocomplex by UV-Irradiation

Neat poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) films and PLLA/PDLA blend films were prepared by solution casting, and their photodegradation by UV-irradiation was investigated using wide-angle X-ray scattering (WAXS), gel permeation chromatography, differential scanning calorimetry, tensile testing, and polarized optical microscopy. The PLLA/PDLA blend film was more photodegradation-resistant than the neat PLLA and PDLA films when photodegradation was monitored by molecular weight, melting temperature, and WAXS crystalline peak positions. This indicates that the chains in both amorphous and crystalline regions of the PLLA/PDLA blend film were photo-cleavage-resistant compared to those of the neat PLLA and PDLA films. The changes in melting temperature and WAXS crystalline peak positions before and after photodegradation respectively indicated the increased crystalline lattice disorder and the decreased crystalline lattice sizes of the neat PLLA and PDLA films, whereas these changes were insignificant for the blend films. Photodegradation caused no significant change in tensile properties, with the exception of significant decreases in the tensile strength and elongation at break of PLLA/PDLA blend film. However, the tensile strength and elongation at break of the PLLA/PDLA blend film retained higher values compared to those of the neat PLLA and PDLA films during photodegradation. In spite of the slower photodegradation of the PLLA/PDLA blend film traced by M _n, T _m, and WAXS crystalline peak positions than that of neat PLLA and PDLA films, the rapid decrease in tensile strength and elongation at break of the former than that of the latter should be due to the highly-ordered structural difference between them, i.e., the three dimensional dry gel of the former and the spherulites of the latter.     

Biodegradable Blends with Potential Use in Packaging: A Comparison of PLA/Chitosan and PLA/Cellulose Acetate Films

Poly(lactic acid) (PLA) is a biodegradable polymer that exhibits high elastic modulus, high mechanical strength, and feasible processability. However, high cost and fragility hinder the application of PLA in food packaging. Therefore, this study aimed to develop flexible PLA/acetate and PLA/chitosan films with improved thermal and mechanical properties without the addition of a plasticizer and additive to yield extruder compositions with melt temperatures above those of acetate and chitosan. PLA blends with 10, 20, and 30 wt% of chitosan or cellulose acetate were processed in a twin-screw extruder, and grain pellets were then pressed to form films. PLA/acetate films showed an increase of 30 °C in initial degradation temperature and an increase of 3.9 % in elongation at break. On the other hand, PLA/chitosan films showed improvements in mechanical properties as an increase of 4.7 % in elongation at break. PLA/chitosan film which presented the greatest increase in elongation at break proved to be the best candidate for application in packaging.     

Characterization and Properties of Reactive Poly (Lactic Acid)/Ethylene–Vinyl Alcohol Copolymer Blends with Chain-Extender

A hydrophilic copolymer, ethylene–vinyl alcohol (EVOH), was incorporated into the poly(lactic acid) (PLA) matrix to improve the barrier property of PLA through twin-screw extrusion rather than the typical coextrusion process. A chain extender, poly[(ethylene)-co-(methyl acrylate)-co-(glycidyl methacrylate)] (PEMG), was used to reduce the probability of the thermal degradation of PLA during melt compounding. Biaxial stretching was used to enhance the microstructure and barrier property of PLA-PEMG/EVOH films. Experimentally, PEMG considerably reduced the probability of the thermal degradation of the PLA-PEMG sample. Biaxial stretching increased the tensile strength and decreased the value of elongation at break of the PLA-PEMG/EVOH80 (PLA/EVOH 100/80) film. Because of the efficient blending of PLA/EVOH in the twin-screw extruder, the dispersion of EVOH in the PLA matrix revealed homogeneous dispersion with a domain size of 1–5 μm. EVOH effectively improved the water vapour transmission rate (WVTR) of PLA through melt blending. Blending PLA-PEMG with EVOH substantially decreased the WVTR from 250 cc—20 μm/m²-day-atm for neat PLA to approximately 65 cc—20 μm/m²-day-atm for the PLA-PEMG/EVOH80 film, a decrease of approximately 74 % compared with neat PLA. Moreover, the WVTR decreased further from 65 cc—20 μm/m²-day-atm for the unstretched PLA-PEMG/EVOH80 film to 6.3 cc—20 μm/m²-day-atm for the film stretched at a stretch ratio of 3.5 × 3.5 and at 100 %/s, a decrease of approximately 90 % compared with neat PLA.     

Effect of Gamma Radiation on the Properties of Crosslinked Chitosan Nano-composite Film

Chitosan nano-composite film crosslinked by citric acid and with glycerol as plasticizer and MgO as antibacterial agent was prepared by casting method. MgO nanoparticles were synthesized via calcination method in furnace at 500 °C for 4 h and characterized by X-ray diffraction and transmission electron microscope. The chitosan nano-composite film with composition chitosan/citric/glycerol/magnesium oxide (1 wt%:1 wt%:75 vol%:10 wt%) has high mechanical properties than other films. The effects of different irradiation doses on the mechanical, thermal and antibacterial activity were investigated. The tensile strength enhanced by increasing irradiation dose up to 10 kGy and the elongation negligible changed as irradiation dose increased. The thermal stability slightly increased up to dose 2.5 kGy then decreased with dose increment. The antimicrobial activity film was studied against white mulberry-borne bacterial pathogens either Gram positive or Gram negative bacteria and has positive impact of gamma irradiation on the antimicrobial activity. The use of the selected chitosan nano-composite film which irradiated by dose of 2.5 kGy and has magnesium oxide of average particle size 54.3 nm as new packaging materials found to improve storage quality and shelf-life of mulberry fruit.     

Comparison of the Effect of Plasticizers on PHBV—and Organoclay—Based Biodegradable Polymer Nanocomposites

The aim of this work was to evaluate the effect of different plasticizers on the morphology, crystallization, and mechanical properties of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)/organomodified montmorillonite (OMt) nanocomposites. We investigated three different plasticizers: dioctyl phthalate (DOP), a commonly used additive in the polymer industry, and two natural and biodegradable plasticizers: epoxidized soybean oil (ESO) and triethyl citrate (TEC). The nanocomposites with 3 wt% OMt were obtained by melt processing in an internal mixer. The plasticizers were used alone or in combination with clay in a concentration of 10 wt%. X-ray diffraction and scanning electron microscopy results revealed a partially intercalated structure. The degree of crystallinity was higher for all of the samples compared to neat PHBV, although the melting temperature decreased with the use of plasticizers combined with OMt. The impact strength results were dependent on the interaction between the components of the system. Triethyl citrate was the most effective plasticizer due to its more pronounced interaction with the PHBV matrix, which yielded improvements in processing conditions and PHBV’s flexibility and impact properties.     

Polyvinyl Alcohol (PVA)/Starch Bioactive Packaging Film Enriched with Antioxidants from Spent Coffee Ground and Citric Acid

The bioactive packaging polyvinyl alcohol (PVA)/starch films were prepared by incorporating combined antioxidant agents i.e. extracted spent coffee ground (ex-SCG) and citric acid. Effect of citric acid content on chemical compatibility, releasing of antioxidant, antibacterial activities, and physical and mechanical properties of PVA/starch incorporated ex-SCG (PSt-E) films was studied. The results of ATR-FTIR spectra showed that antioxidant agents of ex-SCG can penetrate into the film and the ester bond of blended films by citric acid was also observed. The presence of ex-SCG increased efficiency of antioxidant release and antimicrobial activity. The PSt-E film incorporated 30 wt% citric acid showed minimum inhibitory concentration against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The incorporation of ex-SCG and citric acid into film showed a synergistic effect on antibacterial activity. The water resistance and kinetic moisture sorption improved with incorporation of citric acid. The tensile strength and biodegradability of samples were in range of 5.63–7.44 MPa and 65.28–86.64%, respectively. Based on this study, PSt-E film incorporated 30 wt% citric acid can be applied as novel food packaging materials.     

Influence of the Concentrations of Chitosan and Glycerol on Edible Film Properties Showed by Response Surface Methodology

The individual and interactive effects of glycerol and chitosan concentrations on edible film properties were investigated using response surface methodology. The results of ANOVA indicated that all the independent variables exhibited significant effect on the film properties. Chitosan concentration had a positive effect on CO₂ permeability and negative effect on O₂ while the glycerol concentration had a positive effect on permeability to both gases. Regarding water vapor permeability, the chitosan concentration had a negative effect, whereas the glycerol had no influence. Moreover, both chitosan and glycerol concentration influenced the elongation at break point (%A), and only glycerol concentration had a significant effect on tensile strength. Optimization by desirability approach was carried out on the independent variables to get the optimum levels within the experimental conditions. It was found that 1.5 % of chitosan and 25 % of glycerol (wt/wt of chitosan) retarded respiration and showed a strong permeability to water vapor.     

Effect of Hexadecyl Lactate as Plasticizer on the Properties of Poly(<Emphasis Type="SmallCaps">l</Emphasis>-lactide) Films for Food Packaging Applications

In this study, poly(l-lactide) (PLA) films were fabricated by melt processing and the plasticizing effect of hexadecyl lactate (HL) (0, 5, 7.5, 10, and 12.5 wt% on PLA were investigated by scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis, tensile, transparency, and water vapor permeability tests. The SEM analysis revealed that PLA with 10 wt% HL appeared uniform with extra small bumps, confirmed the interaction between PLA and HL. The thermal analysis revealed a glass transition temperature of 57.4 °C for neat PLA film, but the addition of HL elicited a decrease in the temperature of the peak (43.8 °C). The incorporation of plasticizer into PLA resulted in the increase of elongation at break, as well as the decrease of tensile strength and tensile modulus. Even though a decrease in transparency was recorded, the PLA/HL blend films appeared transparent by visually observation. The water vapor permeability of PLA/HL blend films increased with the increase of HL. The PLA/HL blend films could effectively extend the shelf-life of fresh-cut pears as the commercial low density polyethylene films. The results indicated that the properties of PLA films can be modified with the addition of HL and PLA/HL blend films could serve as an alternative as food packaging materials to reduce environmental problems associated with synthetic packaging films.     

Adsorption Kinetics of Dyes in Single and Binary Systems Using Cyanoguanidine-Crosslinked Chitosan of Different Deacetylation Degrees

The crosslinking of chitosan with cyanoguanidine shows some advantages, such as the improved the stability in acid solutions and the decrease of adsorbent cost. In this work, cyanoguanidine-crosslinked chitosan and pure chitosan were prepared to apply in the adsorption of Food Yellow 4 (FY4) and Food Blue 2 (FB2), in single and binary systems. Effects of pH and deacetylation degree (DD) of chitosan in adsorption were evaluated. The adsorbents were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The kinetic data were analyzed by pseudo-first order, pseudo-second order and Avrami models. The conditions of pH 3 and DD 95% were the more suitable to reach the highest adsorption capacities in all experimental assays. Under these conditions, the adsorption capacities for FY4 were approximately of 392 and 200 mg g^?1 and, for FB2 were approximately of 370 and 184 mg g^?1, respectively, in the single and binary systems. The Avrami model was suitable to represent the kinetic curves in all conditions, and the highest adsorption capacities were found for FY4 in binary aqueous system, being for the pure chitosan of 229 mg g^?1 and crosslinked chitosan of 218 mg g^?1. The Langmuir and extended Langmuir models presented a good fit to the equilibrium data in both systems. It was found that, the chitosan crosslinked with cyanoguanidine improved the chemical stability of chitosan as adsorbent.     

The Influence of Artificial Photodegradation on Properties of Poly(3-hydroxybutyrate-<Emphasis Type="Italic">co</Emphasis>-3-hydroxyvalerate)(PHBV)/Graphite Nanosheets (GNS) Nanocomposites

The potential use of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/graphite nanosheets (GNS) as a biodegradable nanocomposite has been explored. PHBV/GNS nanocomposites films were prepared by solution casting at various concentrations of GNS—0.25, 0.50 and 1.00 wt% GNS. The films were exposed to artificial ultraviolet radiation (UV) during 52 h. The effect of GNS on PHBV photodegradation was investigated and compared to neat PHBV film. The artificial photodegradation induced changes in physical (weight loss), chemical carbonyl index by Fourier transform infrared spectroscopy, thermal degree of crystallinity and melting temperature by differential scanning calorimetry and morphological scanning electron microscopy characteristics. Based on the results obtained from aforementioned analyzes it was verified that GNS inhibits the oxidative degradation of PHBV matrix.     

Physical Characterization of Biodegradable Films Based on Chitosan,Polyvinyl Alcohol and <Emphasis Type="Italic">Opuntia</Emphasis> Mucilage

This study aimed to develop and characterize biodegradable films containing mucilage, chitosan and polyvinyl alcohol (PVA) in different concentrations. The films were prepared by casting on glass plates using glycerol as plasticizer. Mechanical properties, water vapor and oxygen barrier, as well as the interaction with water, were measured. The compatibility of the film-forming components and the uniformity of the films were determined by zeta potential and SEM, respectively. The glycerol and mucilage allowed obtaining more hydrophilic films. The barrier properties of the films made from 100 % chitosan were similar to composed films containing PVA up to 40 %. The results of this study suggest that the interaction between chitosan and mucilage could increase water vapor permeability. The films prepared from either 100 % chitosan or PVA showed a more hydrophobic behavior as compared to the composed films. The films were homogenous since no boundary or separation of components was observed, indicating a good compatibility of the components in the films.     

Evaluation of Extracted Chitosan from Portunus Pelagicus for the Preparation of Chitosan Alginate Blend Scaffolds

In recent years there is a growing need in generating a biocompatible and cost effective porous scaffold for tissue engineering purposes. Therefore, this study focused on conversion of the shell waste of locally available crab variety P.pelagicus (Blue swimming crab) into the chitosan scaffold. As the poor mechanical strength of chitosan limits its usage in tissue engineering, it was blended with alginate. The scaffolds were prepared by the freeze gelation method which requires less time and minimum energy, with fewer residual solvent and easier to scale up. To the best of our knowledge there are no reports on scaffold preparation from the extracted chitosan, blended with alginate by freeze gelation method. The biological properties of chitosan-alginate scaffolds (Cts–Alg) were evaluated and compared with those of chitosan scaffolds. The prepared scaffolds were characterized by SEM, swelling property, in vitro enzymatic degradation, and hemo, biocompatibility properties. Chitosan-alginate scaffolds had an average pore size of 40 μm and tensile strength of 0.564 ± 0.0.018 % MPa. Its swelling ratio was 27.5 ± 0.28 %, with mass loss percentage of 10 ± 0.33 % after 4 weeks of degradation. It has exhibited good hemocompatible properties too. Mouse fibroblast 3T3 cells were able to adhere and proliferate well in the blended scaffold. All these results indicated that chitosan-alginate scaffold is a suitable alternative substitute for tissue engineering.     

Grafting of Glycidyl Methacrylate onto Poly(lactide) and Properties of PLA/Starch Blends Compatibilized by the Grafted Copolymer

Poly(lactide)-graft-glycidyl methacrylate (PLA-g-GMA) copolymer was prepared by grafting GMA onto PLA in a batch mixer using benzoyl peroxide as an initiator. The graft content was determined with the ¹H-NMR spectroscopy by calculating the relative area of the characteristic peaks of PLA and GMA. The result shows that the graft content increases from 1.8 to 11.0 wt% as the GMA concentration in the feed varies from 5 to 20 wt%. The PLA/starch blends were prepared by the PLA-g-GMA copolymer as a compatibilizer, and the structure and properties of PLA/starch blends with or without the PLA-g-GMA copolymer were characterized by SEM, DSC, tensile test and medium resistance test. The result shows that the PLA/starch blends without the PLA-g-GMA copolymer show a poor interfacial adhesion and the starch granules are clearly observed, nevertheless the starch granules are better dispersed and covered by PLA when the PLA-g-GMA copolymer as a compatibilizer. The mechanical properties of the PLA/starch blends with the PLA-g-GMA copolymer are obviously improved, such as tensile strength at break increasing from 18.6 ± 3.8 MPa to 29.3 ± 5.8 MPa, tensile modulus from 510 ± 62 MPa to 901 ± 62 MPa and elongation at break from 1.8 ± 0.4 % to 3.4 ± 0.6 %, respectively, for without the PLA-g-GMA copolymer. In addition, the medium resistance of PLA/starch blends with the PLA-g-GMA copolymer was much better than PLA/starch blends.     

Effect of Varying Filler Concentration on Zinc Oxide Nanoparticle Embedded Chitosan Films as Potential Food Packaging Material

Prevailing scenario of non-biodegradable food packaging materials worldwide was the motivation for this research. More than half of the packaging materials used today are non-biodegradable and lack one or the other feature that keeps it from being an ideal food packaging material. Based on the current need of food grade packaging materials, the present study illustrates the amelioration of the properties of biodegradable chitosan films with the incorporation of zinc oxide (ZnO) nanoparticles in varying concentration. The ZnO nanoparticles (ZnONPs) used as fillers in the chitosan films were synthesized by supersaturation method. They were characterized using UV–visible spectrophotometry, X-ray diffraction and field emission scanning electron microscopy (FE-SEM). The particles were observed to be around 100–200 nm in size. The chitosan films with varying concentration of ZnONPs were synthesized and characterized using Fourier transform infrared spectroscopy and FE-SEM. The films were studied for their thermal stability, water vapor transmission rate (WVTR) and mechanical properties. The thermal stability, as determined by Thermo Gravimetric Analysis and Differential Scanning Calorimetry increased slightly with increasing percentage of embedded ZnONPs while a substantial decrease in WVTR was observed. Mechanical properties also showed improvements with 77% increment in tensile modulus and 67% increment in tensile strength. The antimicrobial activity of the films was also studied on gram positive bacterium Bacillus subtilis (B. subtilis) and gram negative bacterium Escherichia coli (E. coli) by serial dilution method. A twofold and 1.5-fold increment in the antimicrobial activity was observed for B. subtilis and E. coli, respectively, with increased ZnONPs concentration in the films from 0(w/w) to 2%(w/w). Films thus prepared can prove to be of immense potential in the near future for antimicrobial food packaging applications.     

Biodegradation Study of Starch-graft-Acrylonitrile Copolymer

In this study the biodegradability of starch-graft-acrylonitrile (St-g-AN) copolymer has been investigated using some microorganisms including Aspergillus niger. The fungus A. niger was isolated from the soil and from the wastewater of an acrylic fiber company. The effects of four factors including environment temperature, primary inoculum concentration, pH and weight of copolymer film, on the biomass generation as a measure of biodegradation rate of copolymer, were studied using Taguchi experimental design. The statistical analysis of the results showed that the primary inoculum concentration and temperature were the most important factors affecting the biodegradation of St-g-AN copolymer. The optimum levels of temperature, pH, inoculum concentration, and weight of films to attain the maximum biodegradation (as much as 8.59 % by weight percentage during 28 days) were obtained as 30 °C, 4.75, 10⁸ spore/mL, and 1.1 g, respectively. The changes in the structure and morphological properties of the copolymer before and after degradation were determined using transform infrared spectroscopy and scanning electron microscopy.     

Experimental Investigation of Cellulose/Silver Nanocomposites Using In Situ Generation Method

Cellulose gel films were prepared by regeneration process using pre-cooled aq.(8 wt% LiOH + 15 wt% urea) mixture as solvent and ethyl alcohol as non solvent. The Terminus cattapa leaf extract diffused wet cellulose films were then dipped in 1–5 mM aq.AgNO₃ solutions to allow in situ generation of silver nanoparticles (AgNPs). Besides the in situ generation, some AgNPs were also formed outside the wet films in the solution. The AgNPs formed outside the films were observed under transmission electron microscope and scanning electron microscope. The nanocomposite films were also characterized by Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis and tensile test. The thermal stability of the composite films was lower than that of the matrix up to a temperature of ~300 °C and afterwards showed a reverse trend. The tensile strength of the nanocomposite films was found to be higher than the matrix but decreased with increasing concentration of aq.AgNO₃. The cellulose/AgNPs composite films showed good antibacterial activity against E. coli (gram positive) and Bacillus sp. (gram negative). Based on the aforementioned properties, the cellulose/AgNPs composite films can be considered for antibacterial packaging and medical applications.     

Microbial Degradation of UV-Pretreated Low-Density Polyethylene Films by Novel Polyethylene-Degrading Bacteria Isolated from Plastic-Dump Soil

Eleven effective low-density polyethylene (LDPE)-degrading bacterial strains were isolated and identified from landfill soil containing large amounts of plastic materials. The isolates belonged to 8 genera, and included Pseudomonas (areroginosa and putida), Sphingobacterium (moltivorum), Delftia (tsuruhatansis), Stentrophomonas (humi and maltophilia), Ochrobacterum (oryzeae and humi), Micrococcus (luteus), Acinetobacter (pitti), and Citrobacter (amalonaticus). Abiotic degradation of LDPE films by artificial and natural ultraviolet (UV)-exposure was analyzed by FT-IR spectroscopy. LDPE films treated with UV-radiation were also inoculated with the isolates and biofilm production and LDPE degradation were measured. Surface changes to the LDPE induced by bacterial biofilm formation were visualized by Scanning Electron Microscopy. The most active bacterial isolate, IRN19, was able to degrade polyethylene film by 26.8?±?3.04% gravimetric weight over 4 weeks. Analysis of 16S rRNA sequence of this isolate revealed 96.97% similarity in sequence to Acinetobacter pitti, which has not previously been identified as a polyethylene-degrading bacterium. Also, most the effective biofilm forming isolate, IRN11, displayed the highest cell mass production (6.29?±?0.06 log cfu/cm²) after growth on LDPE films, showed 98.74% similarity to Sphingobacterium moltivourum.     

Fabrication and Characterization of Biodegradable Composite Films Made of Using Poly(caprolactone) Reinforced with Chitosan

Chitosan was dissolved in 2?% aqueous acetic acid solution and the films were prepared by solution casting. Values of tensile strength (TS), tensile modulus (TM), elongation at break (Eb?%) and water vapor permeability (WVP) of the chitosan films were found to be 30?MPa, 450?MPa, 8?% and 4.7?g?mm/m²?day?kPa, respectively. Poly(caprolactone) (PCL) films were prepared from its granules by compression molding and the values of TS, TM, Eb and WVP were 14?MPa, 220?MPa, 70?% and 1.54?g?mm/m²?day?kPa, respectively. PCL was reinforced with chitosan films, and composite films were prepared by compression molding. Amount of chitosan in the composite films varied from 10 to 50?% (w/w). It was found that with the incorporation of chitosan films in PCL, both the values of TS and TM of composite films increased significantly. The highest mechanical properties were found at 50?% (w/w) of chitosan content. The Oxygen transmission rate (OTR) of composite film was found to decrease significantly than PCL films. Thermal properties of the composite were also improved as compared to PCL. The water uptake test of the composite also showed promising results with a good stability of composite films. The interface of the composite was investigated by scanning electron microscopy and showed good interfacial adhesion between PCL and chitosan films.     

Degradation of a Terephthalate-containing Polyester by Thermophilic Actinomycetes and <Emphasis Type="Italic">Bacillus</Emphasis> Species Derived from Composts

We intended to find thermophilic degraders of terephthalate-containing Biomax^® films. Films in mesh bags were buried in composts (inside temperature: approximately 55–60 °C), resulting in the degradation of them in 2 weeks. Fluorescent microscopy of films recovered from composts showed that microorganisms gradually covered the surface of a film during composting. DGGE analysis of microorganisms on the composted film indicated the presence of Bacillus species as main species (approximately 80% of microbial flora) and actinomycetes (approximately 10–20%) as the second major flora. Isolation of Biomax^®-utilizing bacteria was focused on these two genera: two actinomycetes and one Bacillus species were isolated as pure best degraders from the composted polymer films, which were fragmented into small pieces. All the strains were thermophilic and identified, based on their 16S rDNA analyses. Degradation of polymer films was confirmed by (1) accelerated fragmentation of films in composts, compared with a control (no inoculum) and resultant decrease in molecular weights, (2) growth in a powdered Biomax^® medium, compared with a control without powdered Biomax^®, and (3) production of terephthalate in a powdered Biomax^® medium. In this way, we concluded that these bacteria were useful for degradation of thermostable Biomax^® products.