High Density Poly Research Articles

Development of Wood Apple Jujube Jellies: Physicochemical, Sensorial and Stability Properties

Jujube looks like jelly and is prepared by addition of fruit,sugar ,Gelatin and water. In India production of fruit is second highest and wood apple is seasonal and underutilised fruit so to popularise this underutilised fruit and supply throughout the year, value added product jujube was developed. underutilised fruit so to popularise this underutilised fruit and supply throughout the year, value added product jujube was developed Limonia acidissima is widely recognized for its medicinal properties renowned for its therapeutic benefits and boosts numerous documented medicinal applications. The aim of this study is to develop value added wood apple jujube soft candy product and to evaluate physico-chemical, nutrient, sensory and storage studies of the developed product. The control group (which was made with the addition of 10g of citric acid) achieved the highest over all sensory score of 8.59 followed by wood apple jujube -1(which was made with the addition of 45g of wood apple pulp), recording scores of 7.55. Jujubes exhibited a protein content of 18.25g/100g, a notable moisture level of 47.55g/100g, followed by 32.20g/100g carbohydrates, with the lowest attributed to fat at 0.2g/100g. The amount of crude fiber was measured at 1g/100 g, alongside its calorific value. The jujubes, Wood apple jujube-1 (which comprises 45 g of wood apple and 30 g of sugar), were packed in High density poly ethylene and kept under normal and Refrigerated conditions. A decline in mean scores was observed for appearance (4.65), texture (5.4), color (5.5), aroma (5.75), flavor (5.2), and overall acceptability (4.6) when stored at ambient temperature over a nine-day span compared to the starting values.

Electro-mechanical analysis of nanostructured polymer matrix composite materials for 3D printing using machine learning

Recently, additive manufacturing (AM) techniques like 3D printing have emerged as a potentially game-changing example of digital manufacturing. However, high entry barriers of a tiny material library, different processing defects, and unpredictable product quality are still holding back its widespread use in the industry. Due to its remarkable success in data tasks like classification, regression, and clustering, machine learning (ML) has recently gained a great deal of interest in the subject of the material library. This paper examines the current state of ML applications in several key areas of AM, including polymer matrix composite materials and machine parameter optimization. Composite filaments have been extruded using Polylactic Acid (PLA) as it is a biodegradable material and shows how High-Density Poly Ethylene (HDPE) enhances physical strength. All the parameters for the filament extruder have been designed by machine learning. Thermal stability is a significant concern for polymers that have been overcome by introducing Titanium Dioxide nanoparticles. The microstructure, surface texture, electro-mechanical behavior, and other general features of extruded filaments made from recycled plastics have been investigated. The extrusion temperature, approximated using ML, is in excellent agreement with the surface texture and microstructure of the polymers, as confirmed by FESEM, EDX, and Particle analysis. Extruded filaments experienced 2500 Vs and confirmed their non-conductivity up to 77.7GΩ. Tensile strength and elongation at break, two measures of mechanical properties, have been examined. Incorporation of Titanium Dioxide Nanoparticles improved mechanical properties significantly. When it comes to 3D printing, the physical properties and potential uses of each composite material are different.

Investigate the Processability of Biobased Thermoplastics Used in Nonwoven Fabrics.

The Covid-19 pandemic increased enormously the manufacturing and usage of face masks and other personal protective equipment (PPE), resulting in accumulation of plastic waste and, thus, causing universal environmental concerns. In addressing the issue of waste reduction and finding alternatives for fossil-based products, investigation of different biobased and biodegradable polymers plays a crucial role. This study examines the processability characteristics of three commonly used biobased polymers available in the market: biobased poly(lactic acid) (PLA), partly biobased and biodegradable poly(butylene succinate) (PBS), and biobased high-density poly(ethylene) (BioHDPE). The investigation combines substantial polymer analysis with subsequent processability trials in two different spunmelt processes, namely, meltblow (MB) and the Nanoval technology, aiming to reveal the differences and difficulties in the processing behavior and pointing out advantages and/or disadvantages of the respective polymer/technology combination. In general, the observed processability behavior and outcomes indicate that within the used processes PLA exhibits superior processability compared to PBS and BioHDPE. Both the meltblow and Nanoval processing of PLA demonstrated a consistent production of fibers and efficient uptake without any compromise on the throughput. In contrast, the processing of PBS using Nanoval required the utilization of significantly elevated temperatures, as indicated by a rheological study. Furthermore, the rheological evaluation revealed that the viscosity of BioHDPE was excessively elevated, rendering it unsuitable for effective processing by the Nanoval method. The microfibers in the PLA-based meltblown fabric had a higher surface area, explaining why the PLA fibers were able to function as a barrier and, thus, contribute to the mitigation of air permeability adjustable between 500 and 1000 l·s-1·m-2 and thus competitive or even superior to PP nonwovens of the same fiber diameter and base weight (1480 l·s-1·m-2). Overall, these results showed that PLA can be an alternative raw material for fossil-based nonwovens of PPE applying, especially, the meltblown technique.

Chemical compatibility between poly(ethylene) and cellulose nanofibers from kraft pulps containing varying amounts of lignin: An aqueous acetylation strategy and its effect on biocomposite properties

Previous efforts to acetylate fibers and cellulose nanofibers (CNFs) are methodologically demanding and usually based on organic solvents catalyzed by acids. Hence, the purpose of this study was to introduce an improved method to acetylate unbleached (2 % and 5 % lignin) and bleached fibers (<1% lignin), and the corresponding CNFs, using a one-pot strategy in an aqueous alkaline medium. The lignin content in the pulp fibers (5 %) influenced the morphology of the corresponding fibrillated materials, i.e., increased secondary fines (92 %) and mean fibril area (36 %). Additionally, the pulps and CNFs (0 % and 5 % lignin content) were acetylated and compounded with high-density poly(ethylene) (HDPE). Acetylation improved the mechanical strength from 19 MPa (HDPE) to 30–40 MPa (when including acetylated fibers or CNFs). Finally, acetylation revealed a positive effect on melt-flow-index and elongation at break, and the water absorption of injection molded specimens was reduced to roughly 0.6 % after 10 days of testing.

Characterisation of formulated high-density poly(ethylene) by magic angle spinning nuclear magnetic resonance.

High-density poly(ethylene) (HDPE) is an important class of polymer used extensively in plastic packaging as well as numerous other applications. HDPE has a structure that consists of crystalline (monoclinic and orthorhombic) and amorphous domains. Here, we exploit a range of approaches focusing on magic angle spinning (MAS) nuclear magnetic resonance (NMR) aimed at comparing the effect of the HDPE sample formulation (cutting, shaving and cryomilling), from the commercially available manufactured pellets, into these domains and their quantification. 13C cross polarisation (CP) experiments reveal that these formulated HDPEs are qualitatively different and 13C CP build-up curves and 13C direct excitation experiments enable the content of each domain to be obtained, pointing to an increase of monoclinic domain at the expense of the orthorhombic one upon increased processing. The crystallinity contents obtained compared, in some cases, favourably with those obtained by differential scanning calorimetry (DSC) data. These results provide evidence that the manner of preparation of HDPE pellets modifies the concentration of the various domains and suggest that care should be taken during processing.

Design, Development, and Performance Evaluation of Plastic-based Radial-flow Settling Unit for NFT Aquaponics

Highlights Inclusion of the designed radial flow settler to the aquaponic system helps to remove more than 80% TSS, which is on par with or better in comparison to the TSS removal efficiency of the existing models. Removing excess suspended solids in traditional aquaponic setups could help prevent biofilter choking and hence, water contamination further down the line. The developed radial flow is simple in design, cost-effective, and yet, efficient. Abstract. One cylindrical settler of capacity 200 L (Ø 0.6×0.7 m) with a center-bottom inlet has been designed and developed in High-Density Poly Ethylene (HDPE) under the All-India Co-ordinated Research Project on Plastic Engineering in Agriculture Structures &amp;amp; Environment Management (AICRP on PEASEM) center at ICAR-CIFA, Bhubaneswar for fitting to the developed Nutrient Film Technique (NFT) aquaponics system. The water flow into the settling unit comes from a single-drain fish culture tank with the outlet at the bottom-center with a downward slope of 1:22. The experiment was carried out for the evaluation of the efficiency of Total Suspended Solid (TSS) removal in the developed radial-flow settling unit. The performance is assessed in terms of capturing the suspended solids from the water of aquaculture operation with varying specific gravity (1=SG&amp;gt;2) as well as the skimming of the floating organic surfactants before entering into the biofilter. During the 90 days of study, a total of 60 water samples were collected from the outlet of the fish culture tank and the overflow of the settler, which were filtered through the standard 11 µm pore paper filter for further processing in the laboratory. The average TSS concentration removed was calculated to be 128.55 mg/L on dry weight basis and a mean efficiency of 80.06 ± 9.36% was observed in the experiment with a surface loading rate of 0.00103 m3/min-m2 of the radial flow settler. The right-angle submerged overflow of the settler helped in complete surfactant removal. Keywords: Aquaponics, NFT, Radial-flow, Specific gravity, Suspended solid.

Nano Boron Oxide and Zinc Oxide Doped Lignin Containing Cellulose Nanocrystals Improve the Thermal, Mechanical and Flammability Properties of High-Density Poly(ethylene).

The widely used high-density polyethylene (HDPE) polymer has inadequate mechanical and thermal properties for structural applications. To overcome this challenge, nano zinc oxide (ZnO) and nano boron oxide (B2O3) doped lignin-containing cellulose nanocrystals (L-CNC) were blended in the polymer matrix. The working hypothesis is that lignin will prevent CNC aggregation, and metal oxides will reduce the flammability of polymers by modifying their degradation pathways. This research prepared and incorporated safe, effective, and eco-friendly hybrid systems of nano ZnO/L-CNC and nano B2O3/L-CNC into the HDPE matrix to improve their physio-mechanical and fire-retardant properties. The composites were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, thermo-gravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, horizontal burning test, and microcalorimetry test. The results demonstrated a substantial increase in mechanical properties and a reduction in flammability. The scanning electron microscope (SEM) images showed some agglomeration and irregular distribution of the inorganic oxides.

Morpho-physiological changes in oil palm (Elaeis guineensis Jacq.) tenera hybrid seedlings raised under different shade levels

Climatic conditions prevailing in oil palm growing states of India indicate the need for shade during primary stage of oil palm nursery for optimum growth and vigour of seedlings. Experiments were conducted to standardize the shade requirement based on growth/quality of oil palm seedlings in summer, rainy and winter seasons by providing 25%, 50% and 75% ultra violet stabilized high density poly ethylene (HDPE) shade nets. Results were found significant among the treatments for most of the growth parameters studied over the seasons. Highergrowth for key characters like seedling height, leaf area, collar girth and dry matter production were recorded at 75% shade level. Similarly, higher chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and inter cellular CO2 concentration were observed at 75% shade. Among the season, seedling growth was vigorous in rainy season followed by summer and winter seasons. Hence, provision of 75% shade found to be ideal for raising seedlings during primary stage of nursery in oil palm.

Thermal analysis of sustainable and micro-filler Basalt reinforced polymer biocomposites for lightweight applications

For the past ten years, there has been a trend toward strengthening polymer composites with the help of natural fibers derived from plant and animal sources, which has led to ecological imbalance. Hence, to maintain the ecological balancing factors, the researchers and industrial experts are concentrating on the reinforcement of naturally available mineral materials in polymer products to minimize the polymer percentage and boost the economic feasibility of products with lightweight properties. In fact, incorporating basalt mineral into different polymer matrices is a highly creative notion that might open up some very interesting, uncharted territory. Basalt helps to create a pollution-free environment and balance ecological challenges by reducing the polymer ratio in the objects without many changes in their core properties. Basalt is desirable because of its outstanding thermal and mechanical characteristics, simplicity of processing, affordability, and lack of toxicity. Concerning these points, the current study aims to fabricate mineral particles (basalt)-reinforced (30 wt%) different polymers (synthetic epoxy, bio-epoxy, polyester, vinyl ester, polylactic acid, polypropylene, and high-density polyethylene) composite for lightweight thermal applications. The casting technique was used for the fabrication of thermoset polymer composites, whereas compression molding was employed to fabricate thermoplastic composites after an internal mixing process. The fabricated composites are subjected to thermogravimetric, thermomechanical, and dynamic mechanical analysis to analyze the thermal stability of the resultant composites. The Thermogravimetric analysis revealed that most of the samples exhibited good thermal stability with the addition of 30 wt% basalt fillers. As a result of moisture content as well as certain volatile compounds, if any, only a minimal weight loss in the range of 30 °C to 130 °C was seen at the early phase of heating for all neat and composite samples. The Thermomechanical analysis findings showed that basalt reinforcement at 30 wt% in synthetic epoxy, Polylactic acid, Polypropylene, and High Density Poly Ethylene polymers causes a reduction in dimensional variations up to 70 °C. This is because the basalt particles, particularly in the hard glassy area, limit the passage of molecules at lower temperatures. The higher stiffness of the basalt particles has significantly contributed to the viscoelastic properties of all the thermoset and thermoplastic composites. Because of the extreme closeness and thick packing of the components, which are in a dormant condition, the glassy areas in particular have a greater storage modulus. Based on these outcomes, these basalt-reinforced composites can be employed for lightweight thermal applications, which have the advantage of economic and eco-friendly features.

High Density Poly(ionic liquid)s with Spatial Structure Regulation for Efficient Carbon Dioxide Cycloaddition

AbstractThe synthesis of cyclic carbonate from CO2 and epoxide is one of the valid routes in line with atomic economy to achieve CO2 conversion. Combining the advantages of high activity and easy separation for heterogeneous catalytic reaction system, a series of heterogeneous catalysts poly(ionic liquid)s with high ionic density (HDPILs) were designed and synthesized. Looser structures and high ionic density were obtained by using muti‐center ionic liquids with different number of substituents as cross‐linking agents. Ply[PhSVIM]Br, the copolymerized HDPILs with six substituents on the benzene ring was optimal. The catalyst exhibited excellent catalytic performance for CO2 cycloaddition with 98 % conversion and 99 % selectivity under optimal conditions. These HDPILs have comparable catalytic activity to homogeneous catalysts and convenient product separability. Particularly, combining XPS and DFT, a structural performance relationship was revealed, the multi‐center ionic liquids used instead of the traditional crosslinking agent as the polymeric backbone can contribute to the reduction of the anion and cation binding energy (BE) and freeing of Br−, which leads to efficient catalytic activity. This study provides a novel strategy for developing a highly efficient catalysts for CO2 conversion to high value products.

Characterization of microplastic, metals associated and ecological risk assessment in the topsoil of shiraz metropolis, south west of Iran

This research studied the occurrence, risk assessment and metals associated with microplastic (MPs) in soil of different land-use types in the south west of Iran. One hundred samples were collected from topsoil and MPs were extracted using the floatation method. In total, 9258 MPs particles with mean of 92.85 ± 119.24 particles kg−1 were counted. The mean MPs abundance in urban soils was 2.8 and 3.2 times higher than in industrial and agricultural soils, respectively. Fragment (43%) and small MPs (100–250 μm; 41%), were the dominant shape and size, respectively. Four main polymer types including Poly Ethylene (High Density Poly Ethylene and Low Density Poly Ethylene), Nylon (PA), Poly Propylene (PP), and Poly Styrene (PS) were identified. Nylon (29%) and PE (29%) were dominant polymer types. MPs particles in soil contained different levels of metals such as Cd, Cr, Cu, Fe, Hg, Pb, Zn, and Y, except La and Yb. The mean concentrations of metals were higher in MPs than in soil. The indices of MPs-induced risk (Hstudyarea=16.8) showed a hazard level (III) in the study area. Pollution load index (PLILandusetype) showed hazard level (II) for urban soils and hazard level (I) for industrial and agriculture soils, respectively. Overall, risk index indicated high to extreme danger for MPs pollution in the study area. This is the comprehensive study on the occurrence of soil MPs and associated metals, which provides basic information for a further study concerning ecosystem health in Shiraz.

Evolving Promising Redgram (Cajanas cajan L.) Transplanting Techniques for Better Crop Establishment under Resource Constraint Dryland Areas of Southern India

Background: Redgram a predominant dryland crop is vulnerable to the whims of rainfall at initial stages of crop growth. Moreover, the wider spacing promotes transplanting over conventional method but, appropriate nursery technique is yet to be standardised to prevent root coiling which leads to poor plant stand under main field conditions. Methods: A field experiment was conducted during 2020-21 at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai to identify suitable nursery techniques for raising redgram seedlings. Redgram was raised in poly bag, 98 cone protray, 50 cone protray and high density poly ethylene (HDPE) woven fabric mat for 20 and 30 days before transplanting. The experiment was laid out in randomized block design replicated thrice. Result: The results revealed that, raising redgram seedlings in HDPE woven fabric mat and transplanting at 20 DAS resulted in lesser root length, root volume but with lesser root coiling coefficient which is highly favourable. Moreover, after being transplanted the seedlings recorded higher plant height, leaf area index with increased photosynthetic activity, respiration andchlorophyll content. Similarly, higher yield and benefit cost ratio was attained over the conventional line sowing. Therefore, raising red gram seedlings in HDPE woven fabric mat can be considered as a cost-effective technology to attain higher yields and with the possibility to gap fill under poor seedling establishment without differential harvest maturity under the dry land tracts of southern Tamil Nadu, India.

Identification of Microplastics Using a Custom Built Micro-Raman Spectrometer

Microplastics are plastic particles less than 5 mm in size but larger than 0.1 µm. Widespread microplastic pollution in aquatic and terrestrial environment is raising serious concern globally due to its detrimental impacts on living beings. This urge for the necessity of a sensitive analytical tool, which can facilitate reliable identification of microplastics. Micro-Raman spectroscopy enables molecular level structural details of samples and thus highly preferable for the identification of microplastics in water. Besides being a non-destructive technique enabling fast analysis, this technique requires minimal/no sample preparation. The present work demonstrates the performance of a custom built Micro-Raman spectrometer for the discrimination of various microplastics in water based samples. Micro- Raman analysis have been found quite successful in the identification of Polystyrene (PS), Polyethylene terephthalate (PET), High Density Poly ethylene (HDPE), Low Density Poly ethylene (LDPE) etc. The Micro-Raman spectral data have been capable enough for the discrimination of high-density polyethylene (HDPE,> 0.940 g/cm3) and low-density polyethylene (LDPE,< 0.930 g/cm3) microplastics, especially due to the variations in the C-H stretching vibrations (2825-2970 cm−1). The ratio of intensities of asymmetric CH2 stretching mode (2879 cm−1) and the symmetric CH2 stretching mode (2847 cm−1) are found to be higher for HDPE with respect to LDPE. Moreover, intensity variations were also observed for the antisymmetric and symmetric C-C stretching bands present at 1059 cm−1 and 1126 cm−1 respectively. The band at 1167 cm−1 arising from CH vibration have also shown an intensity enhancement in HDPE samples.

A bio‐based compatibilizer for improved interfacial compatibility in thermally conductive and electrically insulating graphite/high density poly(ethylene) composites

AbstractGraphite is a thermally conductive filler. However, when dispersed into high density poly(ethylene) (HDPE) resin, graphite particles tend to agglomerate and requires a compatibilizer to achieve desired thermal/physical properties. In this study, oleic acid (OA), a bio‐based additive and polyethylene‐polyamines (PEPA) were used to synthesize a new compatibilizer, PEPA‐g‐OA, containing numerous NR2 groups. The experimental results showed that PEPA‐g‐OA can significantly improve the compatibility between graphite particles and the HDPE matrix due to uniform dispersion of graphite in the HDPE matrix. When the graphite content was 25 wt%, the thermal conductivity of the composite recorded 1.2 W m−1 K−1 (three times that of neat HDPE) and the volume resistivity was 1.8 × 109 Ω cm, indicating excellent electrical insulation. Compared to the composites with no graphite content, the properties of the composites with 25 wt% graphite content exhibited narrower melting and crystallization peaks, more stable mechanical properties, and higher ultraviolet aging resistance. Synthesized new bio‐based compatibilizer and thermally conductive and electrically insulating composites developed in this study can be useful in different industrial fields for the preparation of the next generation composites.

Buildup factor calculation for high density poly ethylene, and high density poly ethylene with lead

The buildup factor of cylindrical samples (shields) for High Density Poly Ethylene, High Density Poly Ethylene with lead (HDPE+ Pb) was studied, where the buildup factor calculated using thickness between (0-3) m.f.p. Cs137 sources (Eγ=0.662 MeV) have been used together with scintillation detector NaI(Tℓ) (2.5 x 2.5).These calculations show that the results of (HDPE +Pb) give buildup factor lower than that of (HDPE) as expected due to the addition of lead.

Molecular thermodynamic modeling of surface tension: Extension to molten polymers

A combined molecular thermodynamic model with an equation of state was successfully extended for correlating the surface tension of 7 molten polymers. The model was coming from the combination of a statistical mechanical expression according to Fowler-Kirkwood-Buff approximation with the perturbed hard-sphere-chain equation of statistical association fluid theory by an attractive term of Yukawa tail. The systems under study were of homopolymers type including Poly(ethylene oxide), High-Density Poly(ethylene), Poly(dimethyl siloxane), Poly(vinyl methyl ether), Poly(ethylene glycol), Atactic-Poly(propylene glycol), and Isotactic-Poly(propylene glycol). The model also used the dipole moment of the monomer molecule of those systems as an adjustable coefficient. The model was able to correlate 65 surface tension data points of the above-mentioned polymers in 297–532.2 K range with the average absolute relative deviation (AARD) of 2.00%. In addition, a single layer neural network comprising two input parameters (temperature and soft-core diameter of Lennard-Jones fluid) and 11 neurons was applied to complete the research, achieving more than satisfactory results with the AARD of 0.88%.

Conversion Of GeNose C-19 Plastic Waste And HDPE (High Density Poly Ethylene) Into Alternative Energy Bio-Oil Using The Co-Pyrolysis Method

Background: Covid-19 has spread to various countries in the world, one of which is Indonesia. The positive cases until March 29, 2021, have reached one and a half million cases and still increasing. GeNose is the latest Covid-19 testing tool that is able to detect the presence of Covid-19 with a sensitivity level of 89-92% and a specification of 95-96%. The ease of using GeNose C-19 has increased so that GeNose C-19 plastic waste also increases. If this is not considered, it will cause a new problem, such as the accumulation of plastic waste caused by the use of the GeNose C-19 tool. Method: As solution to handling that problem, we utilize GeNose plastic waste with addition of HDPE (High Density Poly Ethylene) plastic to produce alternative bio-oil energy products. The methods used in this research are quantitative and qualitative methods with literature studies and research, where we collect data from various scientific journal including Garuda Ristekdikti, SINTA, and Google Scholar using the keywords GeNose waste, Pyrolysis, Plastic waste. In addition, we use the research process using a pyrolysis reactor. Result: The resulting liquid from pyrolysis method is in the form of bio oil which can be used as an alternative energy material. However, the bio oil produced from the pyrolysis process does not produce high quantitative results. So, we combine with HDPE plastic with a ratio of 1:1 (Co-Pyrolysis) to get better results quantitative or qualitative and also have a better indication. Conclusion: GeNose plastic waste treatment with the pyrolysis method with the addition of HDPE raw materials produces bio-oil products in larger quantities. In addition, the pyrolysis of GeNose plastic waste with the addition of HDPE, has a better and longer fuel power than bio oil from the pyrolysis of pure GeNose plastic waste. Keywords: Covid, GeNose, HDPE, Pyrolysis.

Learned iterative shrinkage and thresholding algorithm for terahertz sparse deconvolution.

Terahertz sparse deconvolution based on an iterative shrinkage and thresholding algorithm (ISTA) has been used to characterize multilayered structures with resolution equivalent to or finer than the sampling period of the measurement. However, this method was only studied on thin samples to separate the overlapped echos that can't be distinguished by other deconvolution algorithms. Besides, ISTA heavily depends on the convolution matrix consisting of delayed incident pulse, which is difficult to precisely extricate from the reference signal, and thereby fluctuations caused by noise are occasionally treated as echos. In this work, a terahertz sparse deconvolution based on a learned iterative shrinkage and thresholding algorithm (LISTA) is proposed. The method enclosed the matrix multiplication and soft thresholding in a block and cascaded multiple blocks together to form a deep network. The convolution matrices of the network were updated by stochastic gradient descent to minimize the distance between the output sparse vector and the optimal sparse representation of the signal, and subsequently the trained network made more precise estimation of the echos than ISTA. Additionally, LISTA is notably faster than ISTA, which is important for real-time tomographic-image processing. The algorithm was evaluated on terahertz tomographic imaging of a high-density poly ethylene (HDPE) sample, revealing obvious improvements in detecting defects of different sizes and depths. This technique has potential usage in nondestructive testings of thick samples, where echos reflected by minor defects are not discernible by existed deconvolution algorithms.

Selection of recycled waste plastic for incorporation in sustainable asphalt pavements: A novel multi-criteria screening tool based on 31 sources of plastic

This study investigated the suitability of 31 recycled waste plastic samples obtained from 15 major recycling companies across Australia and New Zealand to be used as bitumen/asphalt modifiers. The plastics have been selected to be representative of recycled waste plastic around Australia and New Zealand. The recycled waste plastics belonged to either the post-industrial or post-consumer collection scheme. A new classification scheme was developed to rank each recycled waste plastic based on their chemical and physical properties against those of bitumen/asphalt. Specifically, density, polarity, melting point, solubility and melt flow index of the samples as well as the presence of contaminants, fillers and additives were analyzed for each recycled waste plastic material and their virgin counterpart. These 8 properties were used to rank various sources of recycled low-density poly(ethylene), linear low-density poly(ethylene), high density poly(ethylene) and poly(propylene) in addition to commingled plastics based on their suitability for bitumen modification (wet method). The modification of asphalt via replacement of virgin quarry aggregate with plastic aggregate (dry method) by recycled acrylonitrile butadiene styrene and poly(ethylene terephthalate) was also assessed by considering four criteria of purity, polarity, recycling contamination and hazardous additives. This new multi-criterion ranking approach revealed that low-density and linear low-density poly(ethylene) and acrylonitrile butadiene styrene and poly(ethylene terephthalate) should be preferentially used as bitumen/asphalt modifiers. This tool has been developed for recycling companies and bitumen/asphalt contractors to determine the suitability of recycled waste plastics within asphalt roads by a series of experimental techniques.

Application of Nitrogen Piezoelectric Direct Discharge for Increase in Surface Free Energy of Polymers

The subject of this study is the application of the piezoelectric direct discharge (PDD) operated with nitrogen to control the surface free energy (SFE) of polymers. The activation area, defined as the area of the zone reaching the SFE of 58 mN/m for high-density polyethylene (HDPE) and poly (methyl methacrylate) (PMMA), is characterized. For HDPE, the activation area was characterized as a function of the distance from 1 to 16 mm, the nitrogen flow from 5 to 20 SLM, and the treatment time from 1 to 32 s. For larger distances, where SFE does not exceed 58 mN/m, the water contact angle is evaluated. The activation area for nitrogen PDD is typically a factor of 3 higher than for air with all other conditions the same. A maximum static activation area of 15 cm2 is reached. The plasma treatment of lens panels made of PMMA is presented as application example.