Abstract: Strawberry is one of the most favored fruits all along the world. But due to its vulnerability to microbial contamination and short life storage, there are lots of problems in industrial production and transportation of this fruit. Therefore, lots of ideas have tried to increase the storage life of strawberries especially through proper packaging. This paper works on efficient packaging as well. The primary material used is produced through simple mixing of low-density polyethylene (LDPE) and silver nanoparticles in different weight fractions of 0.5 and 1% in presence of dicumyl peroxide as a cross-linking agent. Final packages were made in a twin-screw extruder. Then, their effect on the quality maintenance of strawberry is evaluated. The SEM images of nano-silver packages show the distribution of silver nanoparticles in the packages. Total bacteria count, mold, yeast and E. coli are measured for microbial evaluation of all samples. Texture, color, appearance, odor, taste and total acceptance of various samples are evaluated by trained panelists and based on 9-point hedonic scale method. The results show a decrease in total bacteria count and mold in nano-silver packages compared to the samples packed in polyethylene packages for the same storage time. The optimum concentration of silver nanoparticles for the lowest bacteria count and mold is predicted to be around 0.5% which has attained the most acceptance from the panelist as well. Moreover, organoleptic properties of strawberry are preserved for a longer period in nano-silver packages. It can be concluded that using nano-silver particles in strawberry packages has improved the storage life and quality maintenance of the fruit.
Abstract: In recent years, polymer/clay nanocomposites have generated great interest in the polymer industry as a new type of composite material because of their superior properties, which includes high heat deflection temperature, gas barrier performance, dimensional stability, enhanced mechanical properties, optical clarity and flame retardancy when compared with the pure polymer or conventional composites. The investigation of change of the tensile properties of organoclay/linear low density polyethylene (LLDPE) nanocomposites with the use of Dioctyl terephthalate (DOTP) (as plasticizer) and calcite (as filler) has been aimed. The composites and organoclay synthesized were characterized using the techniques such as XRD, HRTEM and FTIR techniques. The spectroscopic results indicate that platelets of organoclay were well dispersed within the polymeric matrix. The tensile properties of the composites were compared considering the stress-strain curve drawn for each composite and pure polymer. It was observed that the composites prepared by adding the plasticizer at different ratios and a certain amount of calcite exhibited different tensile behaviors compared to pure polymer.
Abstract: This study evaluated the incidence of concentrated
natural fibre, as well as the effects of adding a crosslinking agent on
the torque when those components are mixed with low density
polyethylene (LDPE). The natural fibre has a particle size of between
0.8-1.2mm and a moisture content of 0.17%. An internal mixer was
used to measure the torque required to mix the polymer with the
fibre. The effect of the fibre content and crosslinking agent on the
torque was also determined. A change was observed in the
morphology of the mixes using SEM differential scanning
microscopy.
Abstract: Waste polyethylene (PE) is classified as waste low
density polyethylene (LDPE) and waste high density polyethylene
(HDPE) according to their densities. Pyrolysis of plastic waste may
have an important role in dealing with the enormous amounts of
plastic waste produced all over the world, by decreasing their
negative impact on the environment. This waste may be converted
into economically valuable hydrocarbons, which can be used both as
fuels and as feed stock in the petrochemical industry. End product
yields and properties depend on the plastic waste composition.
Pyrolytic biochar is one of the most important products of waste
plastics pyrolysis. In this study, HDPE and LDPE plastic wastes were
co-pyrolyzed together with waste olive pomace. Pyrolysis runs were
performed at temperature 700°C with heating rates of 5°C/min.
Higher pyrolysis oil and gas yields were observed by the using waste
olive pomace. The biochar yields of HDPE- olive pomace and LDPEolive
pomace were 6.37% and 7.26% respectively for 50% olive
pomace doses. The calorific value of HDPE-olive pomace and
LDPE-olive pomace of pyrolysis oil were 8350 and 8495 kCal.
Abstract: This work involves the degradation of plastic waste in the presence of three different nanocatalysts. A thin film of LLDPE was formed with all three nanocatalysts separately in the solvent. Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetric (DSC) analysis of polymers suggest that the presence of these catalysts lowers the degradation temperature and the change mechanism of degradation. Gas chromatographic analysis was carried out for two films. In gas chromatography (GC) analysis, it was found that degradation of pure polymer produces only 32% C3/C4 hydrocarbons and 67.6% C5/C9 hydrocarbons. In the presence of these catalysts, more than 80% of polymer by weight was converted into either liquid or gaseous hydrocarbons. Change in the mechanism of degradation of polymer was observed therefore more C3/C4 hydrocarbons along with valuable feedstock are produced. Adjustment of dose of nanocatalyst, use of nano-admixtures and recycling of catalyst can make this catalytic feedstock recycling method a good tool to get sustainable environment. The obtained products can be utilized as fuel or can be transformed into other useful products. In accordance with the principles of sustainable development, chemical recycling i.e. tertiary recycling of polymers along with the reuse (zero order recycling) of plastics can be the most appropriate and promising method in this direction. The tertiary recycling is attracting much attention from the viewpoint of the energy resource.
Abstract: The disposal of waste plastics has become a major worldwide environmental problem. Pyrolysis of waste plastics is one of the routes to waste minimization and recycling that has been gaining interest. In pyrolysis, the pyrolysed material is separated into gas, liquid (both are fuel) and solid (char) products. All fractions have utilities and economical value depending upon their characteristics. The first objective of this study is to determine the co-pyrolysis product fractions of waste HDPE- (high density polyethylene) and LDPE (low density polyethylene)-olive pomace (OP) and to determine the qualities of the solid product char. Chars obtained at 700 °C pyrolysis were used in biocomposite preparation as additive. As the second objective, the effects of char on biocomposite quality were investigated. Pyrolysis runs were performed at temperature 700 °C with heating rates of 5 °C/min. Biocomposites were prepared by mixing of chars with bisphenol-F type epoxy resin in various wt%. Biocomposite properties were determined by measuring electrical conductivity, surface hardness, Young’s modulus and tensile strength of the composites. The best electrical conductivity results were obtained with HDPE-OP char. For HDPE-OP char and LDPE-OP char, compared to neat epoxy, the tensile strength values of the composites increased by 102% and 78%, respectively, at 10% char dose. The hardness measurements showed similar results to the tensile tests, since there is a correlation between the hardness and the tensile strength.
Abstract: This study attempts to understand the effect of different UV irradiation methods on the intercalation of LDPE/MMT nanocomposites, and its molecular behavior at certain isothermal crystallization temperature. Three different methods of UV exposure were employed using single composition of LDPE/MMT nanocomposites. All samples were annealed for 5 hours at a crystallization temperature of 100oC. The crystallization temperature was chosen to be at large supercooling temperature to ensure quick and complete crystallization. The raw material of LDPE consisted of two stable monoclinic and orthorhombic phases according to XRD results. The thermal behavior of both phases acted differently when UV exposure method was changed. The monoclinic phase was more dependent on the method used compared to the orthorhombic phase. The intercalation of clay, as well as, the non-isothermal crystallization temperature, has also shown a clear dependency on the type of UV exposure. A third phase that is thermally less stable was also observed. Its respond to UV irradiation was greater since it contains low molecular weight entities which make it more vulnerable to any UV exposure.
Abstract: Low density polyethylene (LDPE) nanocomposites
with 3, 5 and 7 wt. % cobalt ferrite (CoFe2O4) nanopowder fabricated
with extrusion mixing and followed up by hot press to reach compact
samples. The transmission/reflection measurements were carried out
with a network analyzer in the frequency range of 8-12 GHz. By
increasing the percent of CoFe2O4 nanopowder, reflection loss (S11)
increases, while transferring loss (S21) decreases. Reflectivity (R)
calculations made using S11 and S21. Increase in percent of CoFe2O4
nanopowder up to 7 wt. % in composite leaded to higher reflectivity
amount, and revealed that increasing the percent of CoFe2O4
nanopowder up to 7 wt. % leads to further microwave absorption in
8-12 GHz range.
Abstract: Asphalt concrete pavements have a short life cycle,
failing mainly due to temperature changes, traffic loading and ageing.
Modified asphalt mixtures provide the technology to produce a
bituminous binder with improved viscoelastic properties, which
remain in balance over a wider temperature range and loading
conditions. In this research, 60/70 penetration grade asphalt binder
was modified by adding 2, 4, 6, 8 and 10 percent by weight of asphalt
binder following the wet process and the mineral aggregate was
modified by adding 1, 2, 3, 4 and 5 percent crumb rubber by volume
of the mineral aggregate following the dry process. The LDPE
modified asphalt binder rheological properties were evaluated. The
laboratory results showed an increase in viscosity, softening point
and stiffness of the binder. The modified asphalt was then used in
preparing asphalt mixtures by Marshall Mix design procedure. The
Marshall Stability values for mixes containing 2% crumb rubber and
4% LDPE were found to be 30% higher than the conventional asphalt
concrete mix.
Abstract: Poly bag and mulch films for agricultural field caused
pose environmental problem due to the non-degradable plastics
wastes upon disposal. Thus, a degradable poly bag was designed with
hybrid sago starch (SS) and polyvinyl alcohol (PVA). Two Different
blended compositions of SS and PVA hybrid have been compounded.
Then, the hybrids blended are mixed with linear line density
polyethylene (LLDPE) resin to fabricate poly bag film through
conventional film blowing process. Samples of LLDPE, SS and PVA
hybrid film were exposed to UV light and soil burial. The weight
losses were determined during degradation process. Hybrid film by
degradation of starch was found to hydrolyze and hydroxyl groups
decrease on esterification upon exposure to soil burial and uv
radiation. It was found out that, the hybrid film for 60% of SS
composition showed greatest degradation in soil and UV radiation.
Abstract: Sustainability and eco-friendly requirement of
engineering materials are sort for in recent times, thus giving rise to
the development of bio-composites. However, the natural fibres to
matrix interface interactions remain a key issue in getting the desired
mechanical properties from such composites. Treatment of natural
fibres is essential in improving matrix to filler adhesion, hence
improving its mechanical properties. In this study, investigations
were carried out to determine the effect of sodium hydroxide
treatment on the tensile, flexural, impact and hardness properties of
crushed and uncrushed Luffa cylindrica fibre reinforced recycled low
density polyethylene composites. The LC (Luffa cylindrica) fibres
were treated with 0%, 2%, 4%, 6%, 8% and 10% wt. sodium
hydroxide (NaOH) concentrations for a period of 24 hours under
room temperature conditions. A formulation ratio of 80/20 g (matrix
to reinforcement) was maintained for all developed samples. Analysis
of the results showed that the uncrushed luffa fibre samples gave
better mechanical properties compared with the crushed luffa fibre
samples. The uncrushed luffa fibre composites had a maximum
tensile and flexural strength of 7.65 MPa and 17.08 Mpa respectively
corresponding to a young modulus and flexural modulus of 21.08
MPa and 232.22 MPa for the 8% and 4% wt. NaOH concentration
respectively. Results obtained in the research showed that NaOH
treatment with the 8% NaOH concentration improved the mechanical
properties of the LC fibre reinforced composites when compared with
other NaOH treatment concentration values.
Abstract: This paper illustrates the effect of nano Magnesium
Hydroxide (MH) loading on the thermal properties of Low Density
Polyethylene (LDPE)/Poly (ethylene-co vinyl acetate) (EVA) nano
composite. Thermal studies were conducted, as it understanding is
vital for preliminary development of new polymeric systems.
Thermal analysis of nanocomposite was conducted using thermo
gravimetric analysis (TGA), and differential scanning calorimetry
(DSC). Major finding of TGA indicated two main stages of
degradation process found at (350 ± 25oC) and (480 ± 25oC)
respectively. Nano metal filler expressed better fire resistance as it
stand over high degree of temperature. Furthermore, DSC analysis
provided a stable glass temperature around 51 (±1oC) and captured
double melting point at 84 (±2oC) and 108 (±2oC). This binary
melting point reflects the modification of nano filler to the polymer
matrix forming melting crystals of folded and extended chain. The
percent crystallinity of the samples grew vividly with increasing filler
content. Overall, increasing the filler loading improved the
degradation temperature and weight loss evidently and a better
process and phase stability was captured in DSC.
Abstract: Polymer-modified bitumen is used to combat different pavement distresses and to increase the life span of pavement. Unmodified bitumen cannot perform better with the range extreme minimum and maximum pavement temperatures. The polymers commonly used to modify the bitumen are ethylene vinyl acetate (EVA) styrene butadiene styrene (SBS). The aim this study to compare the performance of EVA modified bitumen with the bitumen modified by waste low density polyethylene (LDPE), polypropylene (PP) obtained from waste carry bags and waste tyre rubber (CR) to encourage the use of waste polymer whose disposal is big problem today, in place of costly virgin polymer. From the experimental study, it was found that waste polymers are also effective in improving the properties bitumen as that of virgin polymer.
Abstract: In this study, tapioca starch, which acts as natural polymer, was added in the blend in order to produce biodegradable product. Low density polyethylene (LDPE) and tapioca starch blends were prepared by extrusion and the test sample by injection moulding process. Ethylene vinyl acetate (EVA) acts as compatibilizer while glycerol as processing aid was added in the blend. The blends were characterized by using melt flow index (MFI), fourier transform infrared (FTIR) and the effects of water absorption to the sample. As the starch content increased, MFI of the blend was decreased. Tensile testing were conducted shows the tensile strength and elongation at break decreased while the modulus increased as the starch increased. For the biodegradation, soil burial test was conducted and the loss in weight was studied as the starch content increased. Morphology studies were conducted in order to show the distribution between LDPE and starch.
Abstract: Polybag and mulch film in agricultural field are used plastics which caused environmental problems after transplantation and planting processes due to the discarded wastes. Thus a degradable polybag was designed in this study to replace non degradable polybag with natural biodegradable resin that is widely available, namely sago starch (SS) and polyvinyl alcohol (PVA). Hybrid blend consists of SS, PVA and linear low density polyethylene (LLDPE) was compounded at different ratios. The thermal and mechanical properties of the blends were investigated. Hybrid films underwent landfill degradation tests for up to 2 months. The films showed gelation and melting transition existed for all three systems with significant melting peaks by LLDPE and PVA. All hybrid blends loses its LLDPE semi crystalline characteristics as PVA and SS systems had disrupted crystallinity and enhanced the amorphosity of the hybrid system. Generally, blending SS with PVA improves the mechanical properties of the SS based materials. Tensile strength of each film was also decreased with the increase of SS contents while its modulus had increased with SS content.
Abstract: In this study tree types of multilayer gas barrier plastic packaging films were compared using life cycle assessment as a tool for resource efficient and environmentally low-impact materials selection. The first type of multilayer packaging film (PET-AlOx/LDPE) consists of polyethylene terephthalate with barrier layer AlOx (PET-AlOx) and low density polyethylene (LDPE). The second type of polymer film (PET/PE-EVOH-PE) is made of polyethylene terephthalate (PET) and co-extrusion film PE-EVOH-PE as barrier layer. And the third one type of multilayer packaging film (PET-PVOH/LDPE) is formed from polyethylene terephthalate with barrier layer PVOH (PET-PVOH) and low density polyethylene (LDPE).
All of analyzed packaging has significant impact to resource depletion, because of raw materials extraction and energy use and production of different kind of plastics. Nevertheless the impact generated during life cycle of functional unit of II type of packaging (PET/PE-EVOH-PE) was about 25% lower than impact generated by I type (PET-AlOx/LDPE) and III type (PET-PVOH/LDPE) of packaging.
Result revealed that the contribution of different gas barrier type to the overall environmental problem of packaging is not significant. The impact are mostly generated by using energy and materials during raw material extraction and production of different plastic materials as plastic polymers material as PE, LDPE and PET, but not gas barrier materials as AlOx, PVOH and EVOH.
The LCA results could be useful in different decision-making processes, for selecting resource efficient and environmentally low-impact materials.
Abstract: Dehydration process was carried out for tomato slices of var. Avinash after giving different pre-treatments such as calcium chloride (CaCl2), potassium metabisulphite (KMS), calcium chloride and potassium metabisulphite (CaCl2 +KMS), and sodium chloride (NaCl). Untreated samples served as control. Solar drier and continuous conveyor (tunnel) drier were used for dehydration. Quality characteristics of tomato slices viz. moisture content, sugar, titratable acidity, lycopene content, dehydration ratio, rehydration ratio and non-enzymatic browning as affected by dehydration process were studied. Storage study was also carried out for a period of six months for tomato powder packed into different types of packaging materials viz. metalized polyester (MP) film and low density poly ethylene (LDPE). Changes in lycopene content and non-enzymatic browning (NEB) were estimated during storage at room temperature. Pretreatment of 5 mm thickness of tomato slices with calcium chloride in combination with potassium metabisulphite and drying using a tunnel drier with subsequent storage of product in metalized polyester bags was selected as the best process.
Abstract: Tomato powder has good potential as substitute of tomato paste and other tomato products. In order to protect physicochemical properties and nutritional quality of tomato during dehydration process, investigation was carried out using different drying methods and pretreatments. Solar drier and continuous conveyor (tunnel) drier were used for dehydration where as calcium chloride (CaCl2), potassium metabisulphite (KMS), calcium chloride and potassium metabisulphite (CaCl2 +KMS), and sodium chloride (NaCl) selected for treatment.. lycopene content, dehydration ratio, rehydration ratio and non-enzymatic browning in addition to moisture, sugar and titrable acidity were studied. Results show that pre-treatment with CaCl2 and NaCl increased water removal and moisture mobility in tomato slices during drying of tomatoes. Where CaCl2 used along with KMS the NEB was recorded the least compared to other treatments and the best results were obtained while using the two chemicals in combination form. Storage studies in LDPE polymeric and metalized polyesters films showed less changes in the products packed in metallized polyester pouches and even after 6 months lycopene content did not decrease more than 20% as compared to the control sample and provide extension of shelf life in acceptable condition for 6 months. In most of the quality characteristics tunnel drier samples presented better values in comparison to solar drier.
Abstract: This paper presents a part of research on the
rheological properties of bitumen modified by thermoplastic namely
linear low density polyethylene (LLDPE), high density polyethylene
(HDPE) and polypropylene (PP) and its interaction with 80 pen base
bitumen. As it is known that the modification of bitumen by the use
of polymers enhances its performance characteristics but at the same
time significantly alters its rheological properties. The rheological
study of polymer modified bitumen (PMB) was made through
penetration, ring & ball softening point and viscosity test. The results
were then related to the changes in the rheological properties of
polymer modified bitumen. It was observed that thermoplastic
copolymer shows profound effect on penetration rather than
softening point. The viscoelastic behavior of polymer modified
bitumen depend on the concentration of polymer, mixing
temperature, mixing technique, solvating power of base bitumen and
molecular structure of polymer used. PP offer better blend in
comparison to HDPE and LLDPE. The viscosity of base bitumen was
also enhanced with the addition of polymer. The pseudoplastic
behavior was more prominent for HDPE and LLDPE than PP. Best
results were obtained when polymer concentration was kept below
3%
Abstract: Tomato powder has good potential as substitute of tomato paste and other tomato products. In order to protect physicochemical properties and nutritional quality of tomato during dehydration process, investigation was carried out using different drying methods and pretreatments. Solar drier and continuous conveyor (tunnel) drier were used for dehydration where as calcium chloride (CaCl2), potassium metabisulphite (KMS), calcium chloride and potassium metabisulphite (CaCl2 +KMS), and sodium chloride (NaCl) selected for treatment.. lycopene content, dehydration ratio, rehydration ratio and non-enzymatic browning in addition to moisture, sugar and titrable acidity were studied. Results show that pre-treatment with CaCl2 and NaCl increased water removal and moisture mobility in tomato slices during drying of tomatoes. Where CaCl2 used along with KMS the NEB was recorded the least compared to other treatments and the best results were obtained while using the two chemicals in combination form. Storage studies in LDPE polymeric and metalized polyesters films showed less changes in the products packed in metallized polyester pouches and even after 6 months lycopene content did not decrease more than 20% as compared to the control sample and provide extension of shelf life in acceptable condition for 6 months. In most of the quality characteristics tunnel drier samples presented better values in comparison to solar drier.