Study of The Biodegradation of Poly (3- Hydroxybutyrate) (PHB) and High-Density Polyethylene (HDPE) by Microorganisms from the Sea waters of the Atlantic Coast of Brazil

Abstract The objective of this study was to evaluate the biodegradation of Poly (hydroxybutyrate) (PHB) and high-density polyethylene (HDPE) in static systems, using as fluid the seawater of the Coastal Region of the State of Pernambuco (Brazil). The physical and chemical modifications of the polymers, as a function of biodegradation, were evaluated by Fourier transform infrared spectroscopy (FTIR), mechanical tensile assay, differential scanning calorimetry (DSC), gravimetric test, and microbiological analysis. Through the FTIR, it was possible to observe in the PHB a decrease of 23.22% in the carbonyl index for the crystalline phase and 32.30% in the amorphous phase after 180 days, which evidences the effect of the biodegradation present. The mechanical properties of PHB were altered with biodegradation, but the thermal properties remained. During the gravimetric tests, there was a reduction in mass and consequently higher degradation rates for PHB, which is corroborated by the microbiological tests of the system. All characterizations demonstrated that the surface of the HDPE is less susceptible to biofilm formation and, consequently, to the enzymatic action of microorganisms. After 180 days of immersion, no significant microbiological degradation was observed in the HDPE, except for some abiotic alterations.

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Tuning the Mechanical Properties of High-Density Polyethylene by ECAE Process

Volume 1: Processing ◽

10.1115/msec2015-9236 ◽

2015 ◽

Author(s):

Catalin Fetecau ◽

Felicia Stan ◽

Laurentiu Sandu ◽

Florin Susac

Keyword(s):

Mechanical Properties ◽

High Density Polyethylene ◽

Equal Channel Angular Extrusion ◽

Morphological Changes ◽

Longitudinal Axis ◽

High Density ◽

Scanning Calorimetry ◽

Plastic Deformations ◽

The Third ◽

Indentation Tests

This paper investigates the ability of the equal channel angular extrusion (ECAE) process to induce morphological changes and hence tune the mechanical properties of high-density polyethylene (HDPE). In this study, differential scanning calorimetry (DSC), compression and cylindrical macro-indentation tests have been used to investigate the evolution of the mechanical properties of HDPE processed by ECAE up to four passes via route BC, i.e. counter clockwise 90° billet rotation about its longitudinal axis. It was found that the ECAE process induces significant plastic deformations with changes in the crystalline structure. The ECAE process increased the HDPE crystallinity by 10 to 15%. The number of ECAE passes has a significant effect on the magnitude of the mechanical properties especially on the elastic modulus and yield stress. Young’s modulus and yield strength decreased with increasing the number of ECAE passes and reached a stationary state after the third pass.

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Tensile and flammability characterizations of corn straw slagging/high-density polyethylene composites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719830459 ◽

2019 ◽

Vol 33 (11) ◽

pp. 1466-1477

Author(s):

Qingfa Zhang ◽

Wenyu Lu ◽

Liang Zhou ◽

Donghong Zhang ◽

Hongzhen Cai ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Tensile Strength ◽

Flame Retardant ◽

High Density Polyethylene ◽

Oxygen Index ◽

High Density ◽

Corn Straw ◽

Scanning Calorimetry ◽

Scanning Electron

Biocomposites were prepared with corn straw slagging (CSS) and high-density polyethylene (HDPE) at four loading levels (10, 20, 30, and 40 wt%) by extrusion method. CSS/HDPE composites were tested by tension, oxygen index meter, differential scanning calorimetry, X-ray diffraction, and the scanning electron microscopy. The scanning electron microscopy showed that CSS was dispersed uniformly in the HDPE matrix and strong interfacial interaction was achieved, which had an important influence on the tensile strength of the composites. The tensile strength of the composites could be improved with proper increase of CSS and reached maximum value at 30 wt% content. Furthermore, the addition of CSS played an important role in improving the flame-retardant ability of CSS/HDPE composites, and the limited oxygen index was 31.26% at 40 wt% content, good flame-retardant effect achieved.

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Sepiolite as a nanofiller to improve mechanical and thermal behavior of recycled high-density polyethylene

Progress in Rubber Plastics and Recycling Technology ◽

10.1177/1477760620918596 ◽

2020 ◽

Vol 36 (3) ◽

pp. 185-195 ◽

Cited By ~ 1

Author(s):

Negin Farshchi ◽

Yalda K Ostad

Keyword(s):

Thermal Behavior ◽

High Density Polyethylene ◽

Low Cost ◽

Process Condition ◽

Softening Temperature ◽

High Density ◽

Plastic Pollution ◽

Scanning Calorimetry ◽

Melt Flow Rate ◽

Recycled Hdpe

Regarding the current demand for controlling plastic pollution, recycling of polymer sounds a promising solution. However, recycling causes mechanical and thermal shortcomings in polymers. Addition of nanoparticles to recycled materials may overcome these shortcomings. Nanocomposites can be achieved either by blending or through polymerization. Sepiolite as a nanoparticle enhances the thermal properties of polymers. In this study, the effect of sepiolite as a nanoparticle has been investigated on the thermal and mechanical behavior of recycled high-density polyethylene (HDPE). Hardness, density, Vicat softening temperature, melt flow rate (MFR), and differential scanning calorimetry has been investigated on recycled HDPE containing different amount of sepiolite. Results showed that both the amount of recycled HDPE and the sepiolite content affect the mechanical and thermal behavior of samples. Increasing the amount of recycled component resulted in increasing of MFR, a slight increase in density, and decrease in Vicat softening point, hardness, melting temperature, and degree of crystallization. As an opposite effect of these to factors on crystallinity of HDPE, sepiolite content has better effects to be considered separately for each recycle content. Sepiolite can be introduced as a low-cost reinforcement filler in recycling industry for tuning new compositions based on process condition, or vice versa.

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Stress-Induced Crystal-to-Crystal Transformations in High-Density Polyethylene-Layered Silicate Nanocomposites: A Spectroscopic Study

Applied Spectroscopy ◽

10.1366/0003702055012519 ◽

2005 ◽

Vol 59 (9) ◽

pp. 1148-1154 ◽

Cited By ~ 6

Author(s):

Spiros Tzavalas ◽

Vasilis G. Gregoriou

Keyword(s):

High Density Polyethylene ◽

Mechanical Strain ◽

Layered Silicate ◽

High Density ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Polyethylene Matrix ◽

Dsc Measurements ◽

Infrared Measurements ◽

Ft Ir

High-density polyethylene (HDPE)–clay nanocomposites have been prepared using the melt intercalation technique. Organically modified montmorillonite at various loadings (0.5–7%) was used as a nanoadditive. Fourier transform infrared spectroscopy (FT-IR) was utilized for the first time to monitor the stress-induced crystal-to-crystal transformations of the polyethylene matrix with respect to the clay loading as well as to the degree of mechanical strain. In addition, polarized infrared measurements revealed information on both the orientation and the stress-induced distortion of the crystals. It was concluded that the crystal-to-crystal transformations are hindered by the presence of the clay, which also prevented the crystals from orienting even at low clay loadings (1%). Finally, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements confirmed the presence of the stress-induced crystalline structures in agreement with the infrared measurements.

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Investigations into the mechanical, morphological and thermal analyses of friction stir processing of high-density polyethylene composites

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405416666892 ◽

2016 ◽

Vol 232 (7) ◽

pp. 1193-1200 ◽

Cited By ~ 1

Author(s):

Jicheng Gao ◽

Chao Li ◽

Yifu Shen

Keyword(s):

Tensile Strength ◽

Friction Stir Processing ◽

High Density Polyethylene ◽

Thermal Analyses ◽

Experimental Tests ◽

Traverse Speed ◽

High Density ◽

Scanning Calorimetry ◽

Friction Stir ◽

Polyethylene Composites

The aim of this work is to fabricate the high-density polyethylene–copper composites by submerged friction stir processing at different traverse speeds. The scanning electron microscopy is used to analyze the distribution of microstructure and particles. The experimental results indicated that the macrostructure morphology, microstructure and tensile strength vary depending on the traverse speed. Compared with the pure high-density polyethylene, Cu-filled polymer composites showed lower tensile strength and higher microhardness. The maximal values of the tensile strength and microhardness were achieved at traverse speeds of 30 and 15 mm/min, respectively. The thermal properties of Cu-filled high-density polyethylene composites were studied by differential scanning calorimetry. The crystalline content of the composites was decreased due to the addition of copper. From the experimental tests, it can be concluded that submerged fiction stir processing has a great potential for producing polymer–metal composites.

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Graphene Nanoplatelet-Reinforced Poly(vinylidene fluoride)/High Density Polyethylene Blend-Based Nanocomposites with Enhanced Thermal and Electrical Properties

Nanomaterials ◽

10.3390/nano9030361 ◽

2019 ◽

Vol 9 (3) ◽

pp. 361 ◽

Cited By ~ 12

Author(s):

Kartik Behera ◽

Mithilesh Yadav ◽

Fang-Chyou Chiu ◽

Kyong Rhee

Keyword(s):

Isothermal Crystallization ◽

High Density Polyethylene ◽

Vinylidene Fluoride ◽

High Density ◽

Scanning Calorimetry ◽

Melt Mixing ◽

Graphene Nanoplatelet ◽

Polyethylene Blend ◽

Poly Vinylidene Fluoride ◽

Mixing Method

In this study, a graphene nanoplatelet (GNP) was used as a reinforcing filler to prepare poly(vinylidene fluoride) (PVDF)/high density polyethylene (HDPE) blend-based nanocomposites through a melt mixing method. Scanning electron microscopy confirmed that the GNP was mainly distributed within the PVDF matrix phase. X-ray diffraction analysis showed that PVDF and HDPE retained their crystal structure in the blend and composites. Thermogravimetric analysis showed that the addition of GNP enhanced the thermal stability of the blend, which was more evident in a nitrogen environment than in an air environment. Differential scanning calorimetry results showed that GNP facilitated the nucleation of PVDF and HDPE in the composites upon crystallization. The activation energy for non-isothermal crystallization of PVDF increased with increasing GNP loading in the composites. The Avrami n values ranged from 1.9–3.8 for isothermal crystallization of PVDF in different samples. The Young’s and flexural moduli of the blend improved by more than 20% at 2 phr GNP loading in the composites. The measured rheological properties confirmed the formation of a pseudo-network structure of GNP-PVDF in the composites. The electrical resistivity of the blend reduced by three orders at a 3-phr GNP loading. The PVDF/HDPE blend and composites showed interesting application prospects for electromechanical devices and capacitors.

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Mechanical Properties, Wettability and Thermal Degradation of HDPE/Birch Fiber Composite

Polymers ◽

10.3390/polym13091459 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1459

Author(s):

Agbelenko Koffi ◽

Fayçal Mijiyawa ◽

Demagna Koffi ◽

Fouad Erchiqui ◽

Lotfi Toubal

Keyword(s):

Mechanical Properties ◽

Differential Scanning Calorimetry ◽

Thermal Degradation ◽

Coupling Agent ◽

High Density Polyethylene ◽

Fiber Composite ◽

Flexural Modulus ◽

High Density ◽

Wood Fibers ◽

Scanning Calorimetry

Wood–plastic composites have emerged and represent an alternative to conventional composites reinforced with synthetic carbon fiber or glass fiber–polymer. A wide variety of wood fibers are used in WPCs including birch fiber. Birch is a common hardwood tree that grows in cool areas such as the province of Quebec, Canada. The effect of the filler proportion on the mechanical properties, wettability, and thermal degradation of high-density polyethylene/birch fiber composite was studied. High-density polyethylene, birch fiber and maleic anhydride polyethylene as coupling agent were mixed and pressed to obtain test specimens. Tensile and flexural tests, scanning electron microscopy, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetry analysis and surface energy measurement were carried out. The tensile elastic modulus increased by 210% as the fiber content reached 50% by weight while the flexural modulus increased by 236%. The water droplet contact angle always exceeded 90°, meaning that the material remained hydrophobic. The thermal decomposition mass loss increased proportional with the percentage of fiber, which degraded at a lower temperature than the HDPE did. Both the storage modulus and the loss modulus increased with the proportion of fiber. Based on differential scanning calorimetry, neither the fiber proportion nor the coupling agent proportion affected the material melting temperature.

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Exploration on compatibilizing effect of nonionic, anionic, and cationic surfactants on mechanical, morphological, and chemical properties of high-density polyethylene/low-density polyethylene/cellulose biocomposites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705715614064 ◽

2015 ◽

Vol 30 (6) ◽

pp. 855-884 ◽

Cited By ~ 5

Author(s):

AK Sudari ◽

AA Shamsuri ◽

ES Zainudin ◽

PM Tahir

Keyword(s):

Mechanical Properties ◽

High Density Polyethylene ◽

Sodium Stearate ◽

High Density ◽

Low Density Polyethylene ◽

Hexadecyltrimethylammonium Bromide ◽

Low Density ◽

Scanning Calorimetry ◽

Melt Mixing ◽

Compatibilizing Effect

Three types of surfactants, specifically cationic, anionic, and nonionic, at different weight percentages were added into high-density polyethylene/low-density polyethylene/cellulose (HDPE/LDPE/cellulose) biocomposites via melt mixing. The cationic and anionic surfactants which are hexadecyltrimethylammonium bromide (HTAB) and sodium stearate (SS), respectively, were added from 4 to 20 wt%, whereas the nonionic surfactant which is sorbitan monostearate (SM) was added from 1 to 5 wt%. The mechanical testing results exhibited that the addition of HTAB increased tensile strength and tensile modulus, while SS deteriorated mechanical properties, while SM increased impact strength and tensile extension of the biocomposites. Based on the mechanical properties results, optimum weight percentages of HTAB and SM were 12 wt% and 4 wt%, respectively. The scanning electron microscopic micrographs displayed that the amount of cellulose fillers pullout decreased with the addition of HTAB, followed by SM, but it increased with SS. Fourier transform infrared spectra, X-ray diffractometer patterns, thermogravimetric analysis results, and differential scanning calorimetry thermograms have confirmed the presence of physical interactions only with the addition of HTAB and SM. Based on the results, compatibilizing effect was found in HTAB, whereas SM has not showed compatibilizing effect but instead plasticizing effect. However, neither compatibilizing nor plasticizing effect was exhibited by SS.

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Performance characteristics of polyethylene/old corrugated container composites reinforced with carbon nanotubes

Journal of Composite Materials ◽

10.1177/0021998316673224 ◽

2016 ◽

Vol 51 (18) ◽

pp. 2665-2673 ◽

Cited By ~ 2

Author(s):

Behzad Kord ◽

Mehdi Roohani

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

High Density Polyethylene ◽

Analysis Data ◽

High Density ◽

Scanning Calorimetry ◽

Polyethylene Matrix ◽

Melt Compounding ◽

The Impact ◽

Thermal Stability Of

The physical, mechanical, thermal, and flammability properties of high-density polyethylene/old corrugated container composites reinforced with carbon nanotubes are presented in this study. High-density polyethylene/old corrugated container composites with different loadings of carbon nanotube (0, 1, 3, and 5 phc) were prepared by melt compounding followed by injection molding. Results indicated that the incorporation of carbon nanotube into high-density polyethylene, significantly improved the mechanical properties of the composites. The tensile and flexural properties achieved the maximum values when 3 phc carbon nanotube was added. Meanwhile, the impact strength of the composites progressively decreased with increasing carbon nanotube content. Furthermore, the water absorption and thickness swelling of the samples remarkably reduced with the addition of carbon nanotube. From thermogravimetric analysis data, the presence of carbon nanotube could enhance the thermal stability of the composites, especially the maximum weight loss rate temperature and also the better char residual was obtained at high loading level of carbon nanotube. Simultaneous differential scanning calorimetry thermograms revealed that the thermal degradation temperatures for the samples with carbon nanotube were much higher than those made without carbon nanotube. Moreover, it was found that the addition of carbon nanotube results in a significant enhancement in flame retardancy of the composites. Morphological observations showed that the nanoparticles were predominantly dispersed uniformly within the high-density polyethylene matrix.

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Mechanical and morphological properties of high density polyethylene and polylactide blends

Journal of Polymer Engineering ◽

10.1515/polyeng-2013-0174 ◽

2014 ◽

Vol 34 (9) ◽

pp. 813-821 ◽

Cited By ~ 8

Author(s):

Gaurav Madhu ◽

Haripada Bhunia ◽

Pramod K. Bajpai ◽

Veena Chaudhary

Keyword(s):

High Density Polyethylene ◽

High Density ◽

Morphological Properties ◽

Heat Of Fusion ◽

Melt Blending ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Blown Film ◽

Blending Method ◽

Spectroscopy Studies

Abstract Polyblend films were prepared from high-density polyethylene (HDPE) and poly(l-lactic acid) (PLLA) up to 20% PLLA by the melt blending method in an extrusion mixer with post-extrusion blown film attachment. The 80/20 (HDPE/PLLA) blend was compatibilized with maleic anhydride grafted polyethylene (PE-g-MA) in varying ratios [up to 8 parts per hundred of resin (phr)]. Tensile properties of the films were evaluated to obtain optimized composition for packaging applications of both non-compatibilized and compatibilized blends. The compositions HDPE80 (80% HDPE and 20% PLLA) and HD80C4 (80% HDPE, 20% PLLA and 4 phr compatibilizer) were found to be optimum for packaging applications. However, better tensile strength (at yield) and elongation (at break) of 80/20 (HDPE/PLLA) blend were noticed in the presence of PE-g-MA. Further, thermal properties and morphologies of these blends were evaluated. Differential scanning calorimetry (DSC) study revealed that blending does not much affect the crystalline melting point of HDPE and PLLA, but heat of fusion of 80/20 (HDPE/PLLA) blend was decreased as compared to that of neat HDPE. Spectroscopy studies showed evidence of the introduction of some new groups in the blends and gaining compatibility in the presence of PE-g-MA. The compatibilizer influenced the morphology of the blends, as apparent from scanning electron microscopy (SEM) and supported by Fourier transform infrared (FTIR).

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