scholarly journals Polyethylene-coffee husk eco-composites for production of value-added consumer products

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Leyla Y. Jaramillo ◽  
Mauricio Vásquez-Rendón ◽  
Sergio Upegui ◽  
Juan C. Posada ◽  
Manuel Romero-Sáez

AbstractThe annual worldwide production of coffee exceeds 10 million tons, and more than 90% of this production is waste, including the husk. On the other hand, plastic consumption increases every year, and sustainable alternatives are necessary to decrease it. This work arises to solve these two problems, and seeks to produce products at an industrial level from polyethylene/coffee husk eco-composites. Both Low Density Polyethylene and High Density Polyethylene were used, and the amounts of coffee husk added as filler were 20 and 40 wt%. The composites were characterized by different morphological, thermal and mechanical techniques. Scanning Electron Microscopy images showed husk particles embedded in the polymer matrix, but with some gaps between the polymer and the filler, because no compatibilizer agent was used. The addition of large amounts of natural filler negatively affected the tensile strength and elongation at break, but increases eco-composites crystallinity, and hence, their Young modulus and hardness. The industrial applicability of the eco-composites was verified through the production of five different consumer products by extrusion and injection processes, using mixtures with 40 wt% coffee husks. All products were obtained without significant defects. If only 3.25 wt% of the polyethylene products produced each year in Colombia did so with the eco-composites developed in this work, all the coffee husk produced in the country would be used, and the emission of about 5.390 million m3 of greenhouse gases would be avoided.

2008 ◽  
Vol 587-588 ◽  
pp. 520-524 ◽  
Author(s):  
Isabel Moura ◽  
Ana Vera Machado ◽  
Fernando M. Duarte ◽  
Gabriela Botelho ◽  
Regina Nogueira

This work aimed to prepare biodegradable polymeric materials based on blends of a synthetic high density polyethylene (HDPE) and biodegradable polymers such as polylactic acid (PCL) and poly(caprolactone) (PLA), in a co-rotating twin-screw extruder. A polyethylene modified with maleic anhydride was used as compatibiliser. The mechanical results showed that the addition of PLA improves the blends stiffness while the addition of PCL leads to materials with a greater elongation at break and a lower Young modulus. This feature is related with the mechanical properties of each material as well as the adhesion between them. Concerning the biodegradability tests, it was found that HDPE/PCL blend presents the highest degree of biodegradability.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 646
Author(s):  
Victor Gomes Lauriano Souza ◽  
Marta M. Alves ◽  
Catarina F. Santos ◽  
Isabel A. C. Ribeiro ◽  
Carolina Rodrigues ◽  
...  

This work aimed to produce bionanocomposites of chitosan incorporated with zinc oxide nanoparticles (ZnO NPs) synthesized using food industry by-products and to characterize them. Such nanoparticles are highlighted due to their low cost, antimicrobial activity, accessibility, and sustainability synthesis. Four different levels of ZnO NPs (0, 0.5, 1.0, and 2.0% w/w of chitosan) were tested, and the bionanocomposites were characterized in terms of their hydrophobicity, mechanical, optical, and barrier properties. Overall, the incorporation of ZnO NPs changed the composites from brittle to ductile, with enhanced elongation at break and reduced Young Modulus and tensile strength. Thus, ZnO NPs acted as plasticizer, turning the films more flexible, due to the presence of organic compounds on the NPs. This also favored permeability of oxygen and of water vapor, but the good barrier properties were maintained. Optical properties did not change statistically with the ZnO NPs incorporation. Thus, the characterization presented in this paper may contribute to support a decision on the choice of the material’s final application.


2020 ◽  
Vol 10 ◽  
pp. 48-55
Author(s):  
H. V. Allakhverdiyeva ◽  
◽  
N. T. Kakhramanov ◽  
I. I. Ismayilov ◽  
◽  
...  

The paper presents the results of a study of the effect of aluminum content on the physic-mechanical properties of composites based on high density polyethylene and low density polyethylene. The properties of metal-filled composites, such as ultimate tensile stress, elongation at break, elastic module, melt flow rate, and heat resistance, were studied. According to the data obtained, the loading of aluminum into the composition of low density polyethylene contributes to a monotonic increase in the ultimate tensile stress and the elastic module. When aluminum is loading into the composition of high density polyethylene, on the contrary, a natural decrease in the ultimate tensile stress and elongation at break of the composites is observed. It is shown that when using a compatibilizer, which is polyethylene modified with maleic anhydride, a significant increase in the ultimate tensile stress of high-density polyethylene composites is observed. A schematic representation of the structure of composites with an interpretation of the probable mechanism of hardening of the material in the presence of a compatibilizer is given. It is shown that the crystallinity of the initial polyethylene has a significant effect on the hardening effect of composites. Electron microscopic micrographs of the structure of a filled composite without and with compatibilizer are given. A comparative assessment shows that in the presence of a compatibilizer, aluminum particles are in the bulk of the polymer matrix, i.e. are not in an isolated state. It is assumed that HDPE macrochains free of maleic anhydride (MA) are involved in the formation of crystalline formations, and small sections of macrosegments containing polar groups of MA are concentrated mainly in amorphous regions and in defects in crystalline structures in the form of passage chains. The concentration of PEMA macrosegments containing MA in the narrow amorphous space of HDPE favorably affects the increase in the adhesive forces of interaction on the surface of aluminum particles, which affects the preservation of the ultimate tensile stress at a relatively high level over a wide range of aluminum concentrations.


2014 ◽  
Vol 27 (2) ◽  
pp. 77-82 ◽  
Author(s):  
H Ahmad ◽  
MA Islam ◽  
MF Uddin

Chopped jute fiber-epoxy composites with varying fiber length (2-12 mm) and mass fraction (0.05-0.35) had been prepared by a heat press unit. The cross-linked product was characterized in terms of specific gravity, thermal conductivity, tensile strength, Young modulus and elongation at break. The transverse thermal conductivities for randomly oriented fibers in the composite were investigated by Lees and Charlton’s method. The tensile strength, Young modulus and elongation at break were investigated by a Universal Tensile Tester. With an increase in the fiber content (irrespective of the fiber length), the thermal conductivity of the composite decreases; the decreasing rate being highest for the fiber length of 2 mm followed by that for the fiber length of 6 and 12 mm. The decreasing rate of the thermal conductivity of the jute-epoxy composite is comparatively higher to that reported in literature for acrylic polymer hemp fiber composite. The tensile strength also decreases with the increase of the fiber content in the composite. The fiber length does not show to have significant effect on the tensile strength of the composite; the variation in strength being masked within experimental error. The Young modulus increases with the increase of fiber content within elastic limit; showing the highest values for the fiber length of 6 mm followed by those for the fiber length of 2 mm and 12 mm. The elongation at break shows slightly increasing trend up to 15% fiber content, but beyond that it decreases drastically. The specific gravity decreases with the increase in the fiber content and thus the recalculated specific tensile strength is found to keep at a stable level of 36MPa up to the fiber content of 20%, and beyond that the specific tensile strength decreases with the increase in the fiber content. It is concluded that jute fiber-epoxy composite could be used as a good heat-insulating material. Further investigation is recommended on the improvement of the thermal insulation keeping the mechanical properties unchanged or even improved. The TGA study is also required to ascertain the field of application of the material. DOI: http://dx.doi.org/10.3329/jce.v27i2.17807 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 2, December 2012: 77-82


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3419 ◽  
Author(s):  
Beata Kaczmarek ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska

Collagen materials are widely used in biomedicine and in cosmetics. However, their properties require improvement for several reasons. In this work, collagen solution as well as collagen films were modified by the addition of ferulic acid (FA). Thin collagen films containing FA were obtained by solvent evaporation. The properties of collagen solution have been studied by steady shear tests. The structure and surface properties of collagen thin films were studied. It was found that for collagen solution with 5% addition of FA, the apparent viscosity was the highest, whereas the collagen solutions with other additions of FA (1%, 2%, and 10%), no significant difference in the apparent viscosity was observed. Thin films prepared from collagen with 1 and 2% FA addition were homogeneous, whereas films with 5% and 10% FA showed irregularity in the surface properties. Mechanical properties, such as maximum tensile strength and elongation at break, were significantly higher for films with 10% FA than for films with smaller amount of FA. Young modulus was similar for films with 1% and 10% FA addition, but bigger than for 2% and 5% of FA in collagen films. The cross-linking of collagen with ferulic acid meant that prepared thin films were elastic with better mechanical properties than collagen films.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6034
Author(s):  
Carlos A. Diaz ◽  
Rahul Ketan Shah ◽  
Tyler Evans ◽  
Thomas A. Trabold ◽  
Kathleen Draper

Biodegradable containers support zero-waste initiatives when alternative end-of-life scenarios are available (e.g., composting, bio digestion). Thermoplastic starch (TPS) has emerged as a readily biodegradable and inexpensive biomaterial that can replace traditional plastics in applications such as food service ware and packaging. This study has two aims. First, demonstrate the thermoformability of starch/polycaprolactone (PCL) as a thermoplastic material with varying starch loadings. Second, incorporate biochar as a sustainable filler that can potentially lower the cost and enhance compostability. Biochar is a stable form of carbon produced by thermochemical conversion of organic biomass, such as food waste, and its incorporation into consumer products could promote a circular economy. Thermoformed samples were successfully made with starch contents from 40 to 60 wt.% without biochar. Increasing the amount of starch increased the viscosity of the material, which in turn affected the compression molding (sheet manufacturing) and thermoforming conditions. PCL content reduced the extent of biodegradation in soil burial experiments and increased the strength and elongation at break of the material. A blend of 50:50 starch:PCL was selected for incorporating biochar. Thermoformed containers were manufactured with 10, 20, and 30 wt.% biochar derived from waste coffee grounds. The addition of biochar decreased the elongation at break but did not significantly affect the modulus of elasticity or tensile strength. The results demonstrate the feasibility of using starch and biochar for the manufacturing of thermoformed containers.


2017 ◽  
Vol 26 (5) ◽  
pp. 096369351702600 ◽  
Author(s):  
Wenjing Xia ◽  
Nianqing Zhu ◽  
Zhongbin Ni ◽  
Mingqing Chen

Biodegradable composites from poly (butylene succinate-co-butylene adipate) (PBSA) and Taihu Lake (Wuxi, China) blue algae were prepared by melt blending. The property and structure of biocomposites were investigated. By adding extra amount of water to blue algae, the formulated blue algae acted as a plastic in the composites during blending, and exhibited a reinforcing effect on the PBSA matrix. With increasing blue algae content, the thermal stability of the composites decreased; the tensile strength at break and elongation at break of the composites reduced, but the Young's modulus of the composites increased. However, the composite with 30% blue algae loading still exhibited good mechanical performance (tensile strength at break of 21.3 MPa, elongation at break of 180%). The fabrication of value-added PBSA/algae composites appeared as an effective approach to reduce the secondary environmental pollution of Taihu blue algae.


2013 ◽  
Vol 795 ◽  
pp. 582-586 ◽  
Author(s):  
M.I.M. Yazid ◽  
A.G. Supri ◽  
Z. Firuz ◽  
Luqman Musa

The effects of benzyl urea into RHDPE/NR/CFF composites with different fibers loading were studied. The composites were prepared using BrabenderPlasticorder at 160 °C with rotor speed of 50rpm. The composites were characterized in respect of their tensile properties and morphology. The results indicated that RHDPE/NR/CFF with benzyl urea composites show higher values of tensile strength, Youngs modulus, but lower elongation at break than RHDPE/NR/CFF composites. RHDPE/NR/CFF with benzyl urea composites gave a better interfacial adhesion between the matrix and the fiber than RHDPE/NR/CFF composites as evidence using SEM.


2015 ◽  
Vol 799-800 ◽  
pp. 57-61
Author(s):  
Anika Zafiah Mohd Rus ◽  
Nurul Syamimi M. Salim ◽  
M.F. Idaris

Among different natural oils, recycling of waste vegetable oils from palm oil is widely explored for polyol synthesis to prevent pollution of waterways and clogging private and municipal drain systems, restaurants and other food preparation. The polyol is solidifying using cross linker and known as Sustainable Polymer (SP). SP is compounded with High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE) by melt-mixing using an injection molding machine. The effect of polymer compounding ratio on the mechanical properties was studied by tensile test. The result indicated that increasing the SP content in LDPE or HDPE was responsible to the reduction of tensile strength and elongation at break of the samples, if compared to pure thermoplastic LDPE and HDPE. This can be verified by increased in SP amount which gave a significant increase in density of the polymer compounds. Morphological of tensile specimens’ surface fracture is revealed the homogenous characteristic with high compatibility properties of sustainable polymer with its compounded polymers.


2015 ◽  
Vol 754-755 ◽  
pp. 201-204
Author(s):  
Ragunathan Santiagoo ◽  
Sam Sung Ting ◽  
Azlinda Abdul Ghani ◽  
Hanafi Ismail ◽  
Awiezan Mislan

The compatibilizer effect of ENR-50 on the tensile properties of high density polyethylene (HDPE)/recycled acrylonitrile butadiene rubber (NBRr)/banana skin powder (BSP)/ composites has been studies. HDPE/NBRr/BSP composites were prepared by melt mixing technique using twin-screw at 180 °C for 9 minutes at rotor speed 50 rpm. The six different composites studied were 100/0/5, 80/20/5, 70/30/5, 60/40/5, 50/50/5, and 40/60/5. As for compatibilized composite a fix 5 wt% of ENR-50 was evaluated. The specimens were analysed for tensile strength and elongation at break (Eb). The results showed that tensile strength and the elongation at break were decreases with the increasing of NBRr loading. However for ENR-50 compatibilized composites, higher tensile strength and elongation at break was recorded. The ENR-50 was found to be an excellent compatibilizer for HDPE/NBRr/BSP composites.


Sign in / Sign up

Export Citation Format

Share Document