Soil Burial Degradation Research Articles

Gelatin capsule waste: new source of protein to develop a biodegradable film

Abstract This work aimed to develop biodegradable films utilizing a new source of gelatin derived from the nutraceutical capsule manufacture waste of coconut with safflower oil, coconut oil and safflower oil. The mechanical, physicochemical, barrier, optical, biodegradation, thermal and morphological properties were evaluated. All films showed low water vapor permeability, intermediate water solubility and high elongation at break. In addition, the films exhibited excellent barrier ability to ultraviolet light. After 15 days of soil burial degradation, the films lost over 68% of initial weight. Scanning electron microscopy showed an appearance free of pores, cracks or bubbles. Furthermore the films showed similar characteristics independent of the waste utilized. The results demonstrated that all the biodegradable films prepared presented appropriate characteristics to be used as substitute to synthetic packaging.

Effects of Biodegradation on the Structure and Properties of Windmill Palm (Trachycarpus fortunei) Fibers Using Different Chemical Treatments.

In this work, windmill palm fiber (WPF), alkali-treated fiber (AF) without hemicellulose and bleached fiber (BF) without lignin were prepared and buried in soil for 30, 60 and 90 days. The surface morphology, chemical composition, crystallinity degree, mechanical properties, and residual mass rate of the samples, before and after biodegradation, were investigated. According to the results, soil burial degradation can remove the parenchyma cells and silica-bodies of WPF and deplete droplets containing the lignin of alkali-treated fiber after it has been buried for 30 days (AF30), and degradation of the single fiber cell wall of bleached fiber after it has been buried for 30 days (BF30). Buried in natural soil, lignin has a slower degradation rate than that of hemicellulose. WPF showed no significant differences in tensile strength after burial in soil for 90 days, because of the integrity fiber structure decreased the biodegradation. The most serious decrease, about 43%, in tensile strength occurred in AF after it had been buried for 90 days (BF90). This basic knowledge may be helpful for windmill palm fiber applications, especially for biodegradable composites.

Evaluation of Water Affinity and Soil Burial Degradation of Thermoplastic Film Derived from Oil Palm Ash-filled Polyvinyl Alcohol

Oil palm ash (OPA) produced through the incineration process were used as a blending material with polyvinyl alcohol (PVOH) to produce a thermoplastic film. Prior to blending, the oil palm ash was characterized using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy, and x-ray diffraction (XRD). The OPA was successfully blended with polyvinyl alcohol to produce plastic films at various ratios of oil palm ash. The properties of these blended polyvinyl alcohol/oil palm ash films were then characterized using SEM, water absorption, and soil burial tests. The water absorption decreased as the content of the oil palm ash increased. Blended polyvinyl alcohol/oil palm ash films showed a better degradation when the concentration of oil palm ash was increased.

Soil Burial Degradation of Oil Palm Shell (OPS) Nanofiller and Phenol Formaldehyde (PF) Resin-Impregnated Oil Palm Trunk Lumber (OPTL): Dimensional Stability and Mechanical Properties

Soil Burial Degradation of Oil Palm Shell (OPS) Nanofiller and Phenol Formaldehyde (PF) Resin-Impregnated Oil Palm Trunk Lumber (OPTL): Dimensional Stability and Mechanical Properties

Physical and Mechanical Properties of Walnut Shell Flour-Filled Thermoplastic Starch Composites

The goal of this work was to evaluate the technical feasibility of walnut shell flour (WSF) as substitute for wood in walnut shell flour/thermoplastic starch (WSF/TPS) composites. The effects of walnut shell flour (WSF), thermoplastic starch (TPS), and nanoclay on the physical and mechanical properties of WSF/TPS composites were investigated. The composite samples were formed in a Colin extruder with four-chamber heat with temperatures. Then, test samples were made using injection molding. The addition of up to 40% WSF greatly improved the tensile strength, flexural strength, and elasticity modulus of the composite. Also, the composites made with higher WSF contents had increased thickness swelling and water absorption. The incorporation of nanoclay (0% to 5%), greatly improved the tensile properties. Soil burial degradation experiments showed that biodegradation was accelerated by the increase of starch in the composite mixtures. The study showed that WSF can be successfully utilized for the manufacture of composites with useful physical and mechanical properties.

Aliphatic poly(ester amide)s from sebacic acid and aminoalcohols of different chain length: Synthesis, characterization and soil burial degradation

High molar mass aliphatic poly(ester amide)s were prepared from sebacic acid and aminoalcohols of different chain length by melt polycondensation and chain extension reactions. Low molecular weight aliphatic poly(ester amide)s were synthesized by melt polycondensation starting from sebacic acid and linear aminoalcohols of different chain lengths, ranging from 2 to 6 methylene groups. Then, chain extension reaction was carried out by using 1,6-hexamethylene diisocyanate (HMDI). The poly(ester amide)s obtained were characterized by viscometry, DSC, MALDI mass spectrometry, and NMR. The poly(ester amide)s with a reduced viscosity ranging from 0.5 to 1.5 dL g−1 showed a good film-ability.The degradability in soil of poly(ester amide) film samples was investigated. The weight loss of commercial poly(3-hydroxy butyrate) (PHB), poly(3-hydroxy butyrate-co-3-hydroxy valerate) 76/24 (P(HB-co-HV) 76/24), poly(caprolactone) (PCL), and two poly(butylene succinate) based samples (Bionolle), was also studied under controlled soil burial conditions. The rates of soil burial degradation of synthetic poly(ester amide)s and commercial biodegradable polyesters having different structures were compared. Interestingly, the poly(ester amide)s synthesized show higher weight loss values than polyester films after 5 and 10 days of soil burial degradation test.

Amorphized cellulose as filler in biocomposites based on poly(ɛ-caprolactone).

Amorphous cellulose particles, obtained through a solvent-free mechano-chemical process, have been tested for the first time as a potential filler for biodegradable composites based on poly(ɛ-caprolactone) (PCL). Commercial cellulose fibers have been also tested for comparison. An effective interfacial strategy based on a compatibilizing agent, a modified PCL, has been used to improve the polymer/filler interfacial adhesion. Composites have been tested through physico-mechanical characterizations and soil burial degradation tests, in order to evaluate the influence of cellulose structure and morphology and polymer/filler interfacial adhesion on the final properties of the realized materials. The use of the amorphous cellulose particles combined with the presence of a suitable interfacial agent has allowed to modulate relevant technological properties of the realized composites, such as tensile and thermal properties, water absorption, water vapor transmission rate and biodegradation kinetic.

Degradation and stability of green composites fabricated from oil palm empty fruit bunch fiber and polylactic acid: Effect of fiber length

In this work, polylactic acid and oil palm empty fruit bunch fiber-reinforced green composites have been fabricated by using random and fixed-length fibers through extrusion followed by injection molding. The prepared composites have been characterized by mechanical tests, thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry. Among all fabricated composites having various sizes and contents of fibers, 30-mm long and 40 wt% empty fruit bunch fiber-incorporated composites show the optimum tensile strength and modulus. As compared to raw empty fruit bunch fiber-loaded composites, simultaneous ultrasound and alkali-treated empty fruit bunch-reinforced composites have revealed improved mechanical performances, enhanced crystallinity, and thermal stability. In case of soil burial degradation studies, treated empty fruit bunch fiber-reinforced composite has been found to be more stable than untreated fiber-reinforced composite.

Effects of dry method esterification of starch on the degradation characteristics of starch/polylactic acid composites

Maleic anhydride esterified corn starch was prepared by dry method. Esterified starch/polylactic acid (PLA) biodegradable composite was produced via melt extrusion method with blending maleic anhydride esterified corn starch and PLA. The influence of the dry method esterification of starch on the degradation characteristics of starch/PLA composites was investigated by the natural aging degradation which was soil burial method. Test results of mass loss rate showed that the first 30 days of degradation was mainly starch degradation, and the degradation rate of esterified starch/PLA (ES/PLA) was slower than that of native starch/PLA (NS/PLA). Therefore, the damage degree of ES/PLA on the surface and inside was smaller than that of NS/PLA, and the infrared absorption peak intensities of CO, CO and CH were stronger than that of NS/PLA. With the increasing time of soil burial degradation, the damage degree of NS/PLA and ES/PLA on the exterior and interior were gradually increased, whereas the infrared absorption peak intensities of CO, CO and CH were gradually decreased. The XRD diffraction peak intensity of PLA in composites showed an increased trend at first which was then followed by a decreased one along with the increasing time of soil burial degradation, indicating that the degradation of amorphous regions of PLA was earlier than its crystalline regions. When the soil burial time was the same, the diffraction peak intensity of PLA in ES/PLA was stronger than that of NS/PLA. If the degradation time was the same, T0, Ti and residual rate of thermal decomposition of NS/PLA were larger than those of ES/PLA. The tensile strength and bending strength of composites were decreased gradually with soil burial time increasing. Both the tensile strength and bending strength of ES/PLA were stronger than those of NS/PLA.

Synthesis, Characterization, and Biodegradation Studies of Poly(1,4-cyclohexanedimethylene-adipate-carbonate)s

Aliphatic/alicyclic poly(1,4-cyclohexanedimethylene-adipate-carbonate)s (PCACs) were synthesized by a transesterification from 1,4-cyclohexamethylendimethanol (1,4-CHDM), adipic acid (AA), diethyl carbonate (DEC), and titanium butoxide Ti(OBu)4 as a transesterification catalyst. The synthesized PCACs were characterized by the Fourier transform infrared (FTIR), X-ray diffraction analysis (XRD), solubility, solution viscosity, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscope (SEM) for their structural, physical, thermal, and morphological investigation. The structure of synthesized PCACs was confirmed by FTIR. All TGA curves of PCACs shows 10% weight loss above 270°C, and they reveal good thermal stability. Biodegradability of PCACs was investigated by hydrolytic degradation at (pH 7.2 and 11.5), enzymatic degradation using Rhizopus delemar lips at 37°C in phosphate buffer solution (PBS), and soil burial degradation at 30°C. The hydrolytic degradation shows the greater rate of weight loss in PBS at pH-11.5 than pH-7.2. The hydrolytic and soil burial degradation shows faster rate of weight loss as compared to enzymatic degradation. Biodegradation rate of PCACs follows the order: PCAC-20 > PCAC-40 > PCAC-60. SEM images show that degradation occurred all over the film surface, creating holes and cracks. These biodegradable PCACs may be able to replace conventional polymer in the fabrication of packaging film in near future.

Biodegradable polypyrrole/dextrin conductive nanocomposite: Synthesis, characterization, antioxidant and antibacterial activity

Combination of a natural biodegradable polymer with a synthetic polymer offers excellent capability in advanced functional materials. For this purpose, biodegradable conductive nanocomposites based on polypyrrole/dextrin have been synthesized by in situ polymerization of pyrrole in the presence of dextrin activated in acidic medium. The nanocomposites were characterized by Fourier transform infrared (FT-IR), Ultraviolet–visible (UV–vis), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and field emission scanning electronic microscopy (FESEM). The conductivity of nanocomposites was investigated by four probe method. The prepared nanocomposites were analyzed for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl assay (DPPH). Our results demonstrated that the conductivity and antioxidant activity of nanocomposites were increased by increasing the amount of polypyrrole in nanocomposite matrix. The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the nanocomposites are effective against all of studied bacteria and nanocomposite 1 effectiveness is higher for Pseudomonas aeruginosa while nanocomposite 2 is effective against Staphylococcus aureus. In addition, in vitro biodegradability study of the polypyrrole/dextrin composites with different weight ratio was investigated in soil burial degradation. The result demonstrated that the composites are biodegradable under natural environment in range of 30.18–74.52% degradation. The observed physical properties of the polypyrrole/dextrin nanocomposites open interesting possibilities for novel applications of electrically conducting polysaccharide-based composites, particularly those that may exploit the antimicrobial nature of the polypyrrole/dextrin nanocomposites.

In vitro degradation assessment of optically active poly(urethane-imide)s based on α-amino acids

The aim of this work is to obtain optically and biologically active poly(urethane-imide)s (PUIs) using N,N’-(pyromellitoyl)-bis-l-tyrosine dimethyl ester (5) as a chiral and biologically active diphenolic monomer. Step-growth polymerization of diol 5 with various aliphatic and aromatic diisocyanates was carried out by gradual heating technique. The resulting PUIs were characterized with FT-IR, and two of them by 1H-NMR spectroscopy and elemental analysis. Thermogravimetric analysis and differential scanning calorimetry were used to determine the thermal properties of the two representative PUIs. The morphology of polymer was studied by X-ray diffraction analysis. Furthermore, in vitro toxicity and biodegradability behaviors of the obtained PUIs were studied in culture media and soil burial degradation which reveals that the synthesized polymers are biologically active and biodegradable in natural environment.

Green Additives for Lubricating Oil

The increasing focus toward diminishing the impact on the environment has driven efforts to develop new environmentally benign lubricating oil additives. Keeping this view in mind, the present investigation comprises the syntheses of homopolymers of sunflower oil (SFO) and soybean oil (SBO) for their evaluation as lube oil additives. Each of them was characterized by spectral techniques (IR, NMR), SEC-GPC, and viscometric analysis. Additive performances mainly as a pour point depressant (PPD) and viscosity index improver (VII) or modifier (VM) were evaluated by standard ASTM methods. The shear stability of the polymers was also determined as per the ASTM D6022-06 method. Biodegradability of all the polymers was tested by the disc diffusion method against fungal pathogens and by a soil burial degradation test (SBT) of the polymer films as per ISO 846:1997. The oil thickening property of the polymers has also been investigated and reported here. Thermal stability of the polymers was determined by thermograv...

Soil burial degradation of new bio-based additives. Part II. plasticized poly(vinyl chloride) films

Commercial sunflower oil was epoxidized, and the epoxidized oil (ESO) was used as a new thermal stabilizer for poly(vinyl chloride) (PVC). Plasticized formulations stabilized with ESO and epoxidized soya bean oil as a commercial stabilizer were evaluated for comparison. Two plasticizers were used, dioctyl phthalate and diisononyl adipate. The aging of the PVC samples was investigated in landfill soil for 24 months. The modifications of the structure of the polymer were followed by Fourier, transform infrared spectroscopy. Furthermore, the variations of density and mechanical properties (tensile and Shore D hardness) were considered, and the variations of the mass of the samples, the glass transition temperature (T-g), the molar mass distribution, and the weight loss were followed as a function of duration of soil burial. The morphological changes were tracked by scanning electron microscopy. Results showed that the nature of the plasticizer and heat stabilizer affects the properties of PVC as well as the phenomena of migration and biodegradation.

New Non-food-Based Composites of Acorn Nutlet and Polycaprolactone: Preparation and Characterization Evaluation

Two dissimilar renewable resource-based thermoplastic acorn nutlet (TPAN) materials were prepared via twin-screw extrusion with the aid of glycerol or monoethanolamine as plasticizers, and then two TPAN/polycaprolactone (PCL) composites with different plasticized systems were prepared. Mechanical test showed that glycerol-based composites had excellent tensile properties, and at a PCL content of 50 wt%, their tensile strength and elongation at break reached 14.4 MPa and 1,361 %, respectively. The micro-morphologic investigation of liquid-nitrogen brittle fracture surface indicated certain interface adhesion between glycerol-based thermoplastic acorn nutlet (GTPAN) and PCL. Dynamic mechanical thermal analysis , differential scanning calorimetry and thermogravimetric analysis demonstrated that the weight ratios of TPAN in composites significantly affected the crystallinity, glass transition temperature (Tg), melting temperature (Tm) and thermal stability of composites. Soil burial degradation analysis displayed that all composites had excellent biodegradability. These results demonstrated that GTPAN/PCL composites had superior mechanical and biodegradable properties, enough to partially replace the conventional thermoplastic plastics.

Nano-scale core–shell structural casein based coating latex: Synthesis, characterization and its biodegradability

Nano-scale core–shell type particle of caprolactam-butylacrylate co-modified casein (CA-CPL-BA) bearing poly(butylacrylate) core and casein-caprolactam shell was synthesized via emulsifier-free polymerization, and was applied as the film-former in leather finishing. By utilizing potassium persulfate–sodium hydrogensulfite as a redox pair during preparing CA-CPL-BA, the grafting extent was superior to that initiated by ammonium persulfate–sodium hydrogensulfite, potassium persulfate or ammonium persulfate. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis results demonstrated that the average size of neat casein particle was around 700nm while the resultant CA-CPL-BA latex particles were significantly decreased to about 80nm in size. Compared with those of neat casein films, enhanced hydrophobicity and higher thermo-stability of the CA-CPL-BA latex film were confirmed by contact angle test and thermal gravimetric (TG) measurement, respectively. Meanwhile, the application performance of the leather samples finished by CA-CPL-BA was proved to be equivalent to that finished by the commercial leather finishing agent product. A possible mechanism of emulsifier-free polymerization for this system was proposed and then proved. Biodegradability tested by soil burial degradation experiments proved that CA-CPL-BA had preferable biodegradability.

Phase Transfer Catalyzed Polymerization of Styrene and Graft Copolymerization of Styrene onto Gelatin

The use of tetrabutylammonium bromide (TBAB), as phase transfer catalyst during polymerization of styrene in the presence of water-soluble radical initiator, potassium persulfate (KPS), and graft copolymerization of styrene onto gelatin, a water soluble polymer, using a water-insoluble radical initiator, benzoyl peroxide (BPO), has been explored in a water-benzene biphasic system. The percentage conversion (Pc) of styrene to polystyrene and percent grafting (Pg) of styrene onto gelatin was studied as a function of various reaction parameters. Under optimum reaction conditions, maximum Pc (76%) was obtained at [KPS] = 12.9 × 10−4 moles/L, [Sty] = 4.3 ×10−3 moles/L, and maximum Pg (87%) was obtained at [BPO] = 4.6× 10−4 moles/L, [Sty] = 13.88 × 10−3 moles/L using [PTC] = 2.89 × 10−4 moles/Lin 10 mL each of water and benzene in 120 min at 60 °C. The graft copolymer, Gel-g-poly(Sty), was characterized by IR, Thermogravimetric Analysis, Scanning Electron Microscopy and swelling behaviour in different solvents. Metal uptake and degradation studies of the grafted sample were also carried out. The grafted sample showed maximum uptake for Cu2+ (88%), Ni2+ (80%) and Fe2+ (50%). Degradation studies of Gel-g-poly(Sty) were carried out by soil burial test and UV radiations. Photo-degradation showed better degradation (5.26% wt. loss) in 32 h of exposure to UV radiations as compared to soil burial degradation (8.46% wt. loss) in 30 days. Gelatin-styrene graft copolymers can thus be used as bio- and photo-degradable materials for environmental management.

Tensile properties, degradation behavior, and water absorption of sago starch plastic films

AbstractSago starch plastic films were prepared by a blending and casting method using various amounts of additives. The additives were glycerol (GLY), polyethylene glycol (PEG), and glutaraldehyde (GLU). Results indicated that the films had an optimum tensile strength of about 2.6 MPa and an optimum elongation at break of 74%. Meanwhile, a GLU content of five parts by weight gave the best tensile properties. Elongation at break of the films increased while tensile strength decreased upon increasing the level of plasticizer (GLY and PEG). The addition of plasticizer also increased the water absorption and soil burial degradation rate. However, the addition of GLU gave opposite results. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers

Evaluation of biodegradation behavior of poly(butylene succinate-co-butylene adipate) with lowered crystallinity by thermally assisted hydrolysis and methylation-gas chromatography

In our previous paper, thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) measurements of poly(butylene succinate-co-butylene adipate) (PBSA) in the presence of tetramethylammonium hydroxide had revealed that the butylene adipate (BA) content in the PBSA films gradually decreased with soil burial degradation time. In order to clarify the cause of this change in copolymer composition, biodegradation behavior of PBSA with lowered crystallinity was evaluated by THM-GC. PBSA film samples with lower degree of crystallinity, prepared by heating and cooling quickly the original commercially available films, were subjected to a soil burial biodegradation test at 30°C for up to 4 weeks. The copolymer compositions between BA and butylene succinate (BS) units in various stages of the degraded film samples were estimated on the basis of chromatograms obtained by THM-GC with less than 5% of the relative standard deviations. As a result, the change in copolymer composition for the heated PBSA films during soil burial was relatively small compared to the original films, suggesting that biodegradation for the heated films proceeded with the comparable rate for both BA and BS-rich moieties due to lowered crystallinity. Based on these results, the reason for the change in copolymer composition observed for the original PBSA films was clarified as follows: (1) the BA-rich moieties in the copolymer chains could show relatively lower crystallinity than the BS-rich moieties and (2) the BA-rich moieties were preferentially biodegraded during soil burial test, leading to the decrease in the BA content as the biodegradation proceeded.

Evaluation of Biodegradability of Poly(Butylene succinate-co-butylene Adipate) on the Basis of Copolymer Composition Determined by Thermally Assisted Hydrolysis and Methylation-Gas Chromatography

Biodegradability of poly(butylene succinate-co-butylene adipate) (PBSA) was studied based on its copolymer composition determined by thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) using trace amounts (20 µg) of the film samples. The copolymer compositions of butylene adipate (BA) units gradually decreased with soil burial degradation time, reflecting preferential biodegradation of BA moieties during soil burial due to their lower crystallinity. Furthermore, local differences in biodegradability of a given PBSA film after soil burial were also successfully evaluated.