During degradation process, LDPE provid- able environment with species of Aspergillus nomius and ed carbon as the sole energy source for microbes [38]. Streptomyces sp. Sharon and Sharon, [39] reported that isolates from Bushnell Haas Broth medium showed decrease in weight 0. Over a period of 90 days, Aspergillus nomius sp. The visi- myces sp. Whereas, in control flask there was no weight loss of the degradation of LDPE by both strains.
The amount of bio- LDPE films, the incubation was carried out at the same tem- mass produced during the growth study with LDPE was perature for a similar period of time but devoid of isolates.
This could be mainly due to availability of extra car- higher degradation rate of LDPE than the rates reported pre- bon source upon degradation of LDPE in the medium. Whereas in Previ- AGS broth supplemented with and without LDPE by observ- ous studies there has been a very slow degradation of LDPE ing the OD of the culture at nm following different time and an enhancement of degradation was accomplished only intervals.
In the control flask there was no significant after LDPE was subjected to prior oxidation [42—44]. The Streptomyces sp. Production of carbon dioxide during Sturm test indicated growth suggests that isolated strain has potency to grow and positive degradability test for the polyethylene. A presence and absence of arginine and glycerol in degradation control experiment was also carried out without microbes. The degradation rates of LDPE were When compared with control flask, test flask had accumulat- similar without the presence of arginine and glycerol in degra- ed CO2 greater than control flask.
This results were similar dation medium. This result confirms that the Streptomyces sp. Figure 2. Graphs represent the percentage weight loss of LDPE films incubated with a Aspergillus nomius and b Streptomy- ces sp.
Similar obser- vation was reported by Tribedi and Sil [36], the formation of AFM Analysis grooves in the treated polyethylene after the incubation with Development of microcolonies of different microbes on Pseudomonas sp. AKS2 in the biofilm were seen through the surface of polyethylene and penetration of hyphal struc- AFM micrographs.
From Figures applied for the investigation of polyethylene degradation, 4b and 4c it can observe that the surface of the LDPE films the prevailing methods are FTIR, GCMS, and nuclear magnet- treated with both the isolates show roughness and grooves. Albertsson et al. Mahalakshmi and Siddiq, [53] has efficient technique for identifying the degraded compounds studied the degradation of polyethylene by consortium of six in abiotic and biotic degradation of LDPE film. In our stud- potential bacterial strains.
They reported that the consortium ies, degradation products after exposure to both Aspergillus were efficiently degraded polyethylene within 30 days and the nomius and Streptomyces sp. Analysis of chemical composition of LDPE films by hexanol, 1-methyl 1-methylethenyl -acetate and benzene,1,2- GCMS revealed the presence of non-toxic compounds such methylenedioxy propenyl.
Abrusci et al. They confirmed that the more effi- were detected after incubation with Aspergillus nomius for cient chain scission of the polymer due to the catalytic effect of 90 days which are: phenol, 3,5-bis 1,1-dimethylethyl ; 2-t- the pro-oxidant. Their findings support the previous work on butylchloromethylmethyloxoimidazolidinecarboxylic; biodegradation of LDPE.
Our results demonstrated higher deg- dotriacontane; ethyl methyl-hexadecanoate; diethyl phthal- radation rates of LDPE without any pretreatment, compared ate; benzene, 1,3-bis 1,1-dimethylethyl ; dodecane, 1-fluoro; with degradation rates reported by Abrusci et al. FTIR spectra Figure 5 of the methyloxoimidazolidinecarboxylic; tetrapentacontane; 2,6, test samples displayed the formation of new peaks and 10,14,18,tetracosahexaene, 2,6,10,15,19,hexamethyl-, all- breakdown of some bonds.
Peak at Similarly, Devi et al. A peak at The intensity of the peak products of LDPE by Achromobacter denitrificans strain S1 was increased in the region of Satlewal, A. C O stretch of aldehyde group appeared at NAH bend of aldehyde group appeared at using an indigenously developed microbial consortium, Peaks at Sudhakar, M. Marine microbe-mediated biodegradation of low- In case of Streptomyces sp. Bonhomme, S.
Environmental biodeg- found to attribute to CAH stretch of alkyne group. Augusta, J. A rapid Peak at The peaks from Koutny, M. Acquired biodegradability of When compared with the untreated sample, treated sam- polyethylenes containing pro-oxidant additives, Polymer ples showed a substantial decrease in the peaks at marginal Degradation Stability, 91, — Hadad, D. Biodegradation bacterial isolates on the LDPE films. Kumar and Jha [55] of polyethylene by the thermophilic bacterium Breviba- reported polyethylene biodegradation was further confirmed cillusborstelensis, Journal of Applied Microbiology, 98, by an increase in the keto carbonyl bond index, the ester — Sivan, A.
Biofilm devel- tra. However, in contrast with the study of Alberts- 72, — Yamada-Onodera, K. Degradation of Polyethyl- incubation with Aspergillus nomius and Streptomyces. Sudha- ene by a fungus, Penicillium simplicissimum YK, Poly- kar et al.
Other Karlsson, S. Bio- scientists have also observed visible changes in biodegrada- degradation of polyethylene and the influence of surfac- tion of synthetic polymers before and after exposure to tants, Polymer Degradation Stability, 21, — Albertsson, A. In conclusion, this study demonstrates degradation of LDPE The shape of the biodegradation by Aspergillus nomius and Streptomyces sp. Pongdhorn Saeoui. Download PDF. A short summary of this paper.
Mechanical and thermal properties of thermoplastic elastomer based on low density polyethylene and ultra-fine fully-vulcanized acrylonitrile butadiene rubber powder …. A Accepted 16 August simple blending technique was utilized as an alternative to a complex dynamic vulcani- zation process typically used for the preparation of TPVs.
As expected, with increasing UFNBRP loading, the elastic contribution increases as evidenced by the decreases in sensitivity of storage modulus to test frequency and in creep compliance. The rheological results are in line with the improvements in rebound resil- ience and compression set.
The presence of chemical crosslinks in UFNBRP in conjunction with the formation of a transient network of rubber particles is thought to be responsible for such increase in elastic response. All rights reserved. Introduction rubber phase is not vulcanized. To gain TPVs with good properties, high shear stress E-mail address: sccsr mahidol. Saleesung et al. Basically, UFRP is prepared by irradiating rubber latex and subsequently 2. Rheological properties spray drying. Particle size of the UFRP has been were investigated using a parallel plate rheometer Physica claimed to be in a range of 50— nm by controlling MCR , Germany with a mm diameter grooved rotor.
Strain and frequency sweep tests toughening thermoplastics [2,4,6—9]. Various thermo- were conducted by varying strain from 0. Dynamic mechanical behavior Santoprene and Geolast. These are different in their elas- A dynamic mechanical thermal analyzer Gabo model tomeric phase, i. However, this technique requires costly processing equipments. Hence, the present work aims to prepare TPVs 2. Rheological and crystallization behavior as A second run with the same heating rate was performed and well as mechanical properties and phase morphology of the result recorded.
Mechanical properties Tensile tests were conducted using a universal tensile 2. The compression set test was carried out blade rotors and having a mixing chamber volume of using a compression device as per ISO Rebound 79 cm3.
Thereafter, the blend was sheeted on a cooled 2-roll mill. For the test specimens to be 2. In effect, the onset of the non-linear nitrogen, and etched by hot xylene to remove the LDPE viscoelastic region is controlled by the disruption of phase to enhance phase contrast of the SEM image.
Results and discussion pronounced in the low frequency region. This implies an increase in elastic contribution of the chemical crosslinks in 3.
This implies the enhancement in elastic contri- magnitude of J could be observed with increasing UFNBRP bution of the blends caused by the characteristics of the loading, which is attributed to the molecular mobility vulcanized rubber particles.
This phenomenon is some- restriction via chemical crosslinks in rubber particles, as times known as the dilution effect [21—24]. In addition, it is discussed previously. Nevertheless, at high strain beyond particles having chemical crosslinks. It is evident from the the critical shear strain, such transient network is disrupted rheological results that the blends with high UFNBRP loading could exhibit viscoelastic response close to a vulcanized rubber.
Dynamic mechanical properties Fig. As illustrated in Fig. Melting and crystallization behavior Fig. Such suppression in crystallization might be caused by the UFNBRP particles locating in the interlamellar spaces and, thus, the reduction in enthalpy of fusion and degree of crystallinity [25]. Such decreases can Fig. Evidently, the incorporation of be attributed to the dilution effect, i.
In other words, the elastic contribution of the degree of crystallinity, as presented previously in Table 2, TPVs prepared in this work could successfully be enhanced and deterioration of tensile properties.
As expected, the hardness decreases with 3. The deformation taking place in the Results of oil swelling tests performed at room temper- hardness test is relatively small and largely near the test ature for 7 days are presented in Table 4.
Swelling magnitude piece surface so correlation with M5 would be expected. It is known that increase, which is more obvious when viewing their relative LDPE matrix is a thermoplastic material having excellent values. Herein, we report … Expand.
X-ray diffraction spectroscopy of polymer nanocomposites. Abstract The development of polymer nanocomposites PNCs constitutes an essential component of material research in the twenty-first century. Materials Science, Medicine. Low-density polyethylene films incorporated with silver nanoparticles to promote antimicrobial efficiency in food packaging.
Medicine, Materials Science. View 1 excerpt, cites results. Role of characterization techniques in evaluating the material properties of nanoparticle-based polymer materials. Abstract There is a growing interest on polymer materials reinforced with the various nanoparticles in last few decades.
Characterization and analysis of the nanoparticles and the polymers … Expand. Abstract Nanocomposites based on low density polyethylene, containing of 3 or 6 wt. In order to increase the miscibility of … Expand. The … Expand. A wide variety of Actinomycetes like Streptomyces strain and Materials and Methods fungi like Aspergillus and Penicillium have been used in research to facilitate this process Materials Gu, Low density polyethylene Sheets and Hussein et al.
Medium El-Shafei et al. They isolated eight different strains of CuSO4. H2O 0. Yamada-Onodera et al. Sea water samples were collected from red sea coast nearby Jeddah province, Saudi Mahalakshmi and Andrew, mentioned Arabia.
Samples collect in sterilize bottle and that fungi are widely used in bioremediation transfer to lab. One of the widely Serial dilution method was used to isolate the reported fungi, Phanerochaete fungi. Isolated fungi were identified based on their Sowmya et al. Fusarium sp and examine their efficiency in Identification was done by following the keys biodegradation of polyethylene by using FTIR of Raper and Fennell Sci 6 8 : Screening of polyethylene degrading fungi Morphological changes on solid medium Untreated polyethylene films were cut into LDPE powder was added to synthetic small pieces and added to flasks ml medium at a concentration of 0.
Fungal isolates were prepared for analysis by scanning which gave maximum diameter were selected electron microscope to check the changes on for further screening of biodegradation rates.
These isolates were water for 20 min. Four LDPE sheets of screened to examine their activity in similar weight were placed in Petri plates degrading polyethylene on synthetic mineral containing the Synthetic medium. Marine fungi usually tolerated with strict conditions in water. Table 1 shows fungi These sheets were inoculated with fungi using which showed maximum growth on synthetic the cork borer.
The Petri plates were medium. F10 were selected based on a colony diameter growth. Other isolates showed Detection of biodegradation of moderate activity in a growth on medium polyethylene supplement with polyethylene as a sole source of carbon. This result agrees with Sindujaa et Weight reduction al.
Sci 6 8 : of LDPE compared to initial weight. Fungal strain treated with different fungi. Rani and singh, reported that Fusarium shows the best degradation In the study of Raaman et al.
Aspergillus species were also grown adhering on this inert surface and also on LDPE film Das and Kumar, utilizing it as the only carbon and energy reported that the microbial colonization of a source which was evident by increase in the polymer surface is the first requirement for its fungal growth. Kavitha et al.
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