scholarly journals Transforming Marble Waste into High-Performance, Water-Resistant, and Thermally Insulative Hybrid Polymer Composites for Environmental Sustainability

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1781 ◽  
Author(s):  
Payal Bakshi ◽  
Asokan Pappu ◽  
Ravi Patidar ◽  
Manoj Kumar Gupta ◽  
Vijay Kumar Thakur

Marble waste is generated by marble processing units in large quantities and dumped onto open land areas. This creates environmental problems by contaminating soil, water, and air with adverse health effects on all the living organisms. In this work, we report on understanding the use of calcium-rich marble waste particulates (MPs) as economic reinforcement in recyclable polypropylene (PP) to prepare sustainable composites via the injection molding method. The process was optimized to make lightweight and high-strength thermally insulated sustainable composites. Physicochemical, mineralogical, and microscopic characterization of the processed marble waste particulates were carried out in detail. Composite samples were subsequently prepared via the injection molding technique with different filler concentrations (0%, 20%, 40%, 60%, and 80%) on weight fraction at temperatures of 160, 180, and 200 °C. Detailed analysis of the mechanical and thermal properties of the fabricated composites was carried out. The composites showed a density varying from 0.96 to 1.27 g/cm3, while the water absorption capacity was very low at 0.006%–0.034%. Marble waste particulates were found to considerably increase the tensile, as well as flexural, strength of the sustainable composites, which varied from 22.06 to 30.65 MPa and 43.27 to 58.11MPa, respectively, for the molding temperature of 160 °C. The impact strength of the sustainable composites was found to surge with the increment in filler concentration, and the maximum impact strength was recorded as 1.66 kJ/m2with 20% particulates reinforcement at a molding temperature of 200 °C. The thermal conductivity of the particulates-reinforced sustainable composites was as low as 0.23 Wm−1K−1 at a 200 °C molding temperature with 20% and 40% filler concentrations, and the maximum thermal conductivity was 0.48 Wm−1K−1 at a 160 °C molding temperature with 80% filler concentration. Our findings have shown a technically feasible option for manufacturing a lightweight composite with better mechanical and thermal properties using marble waste particulates as a potential civil infrastructural material.

2018 ◽  
Vol 22 ◽  
pp. 23-33 ◽  
Author(s):  
Seenaa I. Hussein

In this research, we have prepared epoxy/graphene nanocomposites (graphene content: 1, 3, 5, 7, and 9 wt%) to investigate some mechanical (impact strength, hardness, and Brazilian tests) and thermal properties (thermal conductivity and thermogravimetric analysis). Our results show that the impact strength, hardness, and compression strength values increased to 5.04 kJ/m2, 79.8, and 27.85 MPa, respectively, as increasing graphene content up to 5 wt% and then decreased for further increasing of the graphene content. The observed reduction in the hardness could be attributed to the samples brittleness. On the other hand, the thermal conductivity increased with increasing the graphene content because of the high thermal conductivity of graphene and thus the efficiency increase with increasing of graphene content. In addition, the thermal stability of epoxy/graphene composite increase compared with pure epoxy resin, while the activation energy for samples consists of 9 wt% graphene greater than those containing 1 wt% graphene.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3047 ◽  
Author(s):  
Young Shin Kim ◽  
Jae Kyung Kim ◽  
Euy Sik Jeon

Among the composite manufacturing methods, injection molding has higher time efficiency and improved processability. The production of composites via injection molding requires a pre-process to mix and pelletize the matrix polymer and reinforcement material. Herein, we studied the effect of extrusion process conditions for making pellets on the mechanical and thermal properties provided by injection molding. Polyamide 6 (PA6) was used as the base, and composites were produced by blending carbon fibers and Al2O3 as the filler. To determine the optimum blending ratio, the mechanical properties, thermal conductivity, and melt flow index (MI) were measured at various blending ratios. With this optimum blending ratio, pellets were produced by changing the temperature and RPM conditions, which are major process variables during compounding. Samples were fabricated by applying the same injection conditions, and the mechanical strength, MI values, and thermal properties were measured. The mechanical strength increased slightly as the temperature and RPM increased, and the MI and thermal conductivity also increased. The results of this study can be used as a basis for specifying the conditions of the mixing and compounding process such that the desired mechanical and thermal properties are obtained.


Author(s):  
Youssef El Moussi ◽  
Laurent Clerc ◽  
Jean-Charles Benezet

The use of bio-based concretes performed with lignocellulosic aggregates constitute an interesting solution for reducing the energy consumption, greenhouse gas emissions and CO2 generated by the building sector. Indeed, bio-based materials could be used as an alternative of traditional materials such as expended polystyrene and mineral resources (e.g. glass and rock wools) for insulation. Furthermore, these bio-based concretes are known for their interesting insulation properties, indeed they allow to enhance thermal properties of buildings and enables moisture management which lead to design efficient building materials. For this purpose, bio-based concrete using rice straw as aggregate are studied in this present work. The impact of the characteristics of rice straw particle (particle size distribution, bulk density, and water absorption capacity, etc.) on both the mechanical and thermal properties of the bio-based concrete are investigated. Five formulations of rice straw concrete are examined, compared and then classified in terms of insulation properties and mechanical properties. The assessments are based on the measurement of density and thermal conductivity. The variation of compressive strength in function of the characteristics (mean particle length) of rice straw particle are assessed and discussed. The investigation covers also the porosity and density. Tests are also carried out on agricultural by-products with a view to highlight their chemical, physical and structural proprieties. The results show that the use of large particles with low water absorption capacity induce lighter concretes with the density between 339 and 505 kg/m3 and lead to a high compressive strength with a high mechanical deformability. Furthermore, it appears that an increase in the average length of rice straw particle lead to decrease of thermal conductivity of bio-based concretes. It varies from 0.062 to 0.085 W/(m.K).


2012 ◽  
Vol 535-537 ◽  
pp. 103-109 ◽  
Author(s):  
Xiang Min Xu ◽  
Li Ping Guo ◽  
Yu Dong Zhang ◽  
Zhi Jun Zhang

The polyoxymethylene-based composites containing reactable nano-SiO2were prepared in a twin-screw extruder by melt compounding, and mechanical and thermal properties of pure polyoxymethylene (POM) and composites were investigated. The results showed that reactable nano-SiO2could reinforce the tensile strength and Young’s modulus of composites. To the impact strength of composites, there was obvious improvement when a small amount of silica was added into POM. With the increase of silica content, the impact strength of composites showed a gradually decrease trend. It was worthy to note that reactable nano-SiO2could significantly increase the decomposition temperature of POM. When the content of reactaSubscript textble nano-SiO2was up to 5 wt%, the degradation temperature of composites could increase about 38.3°C under nSubscript textitrogen atmosphere and 43.8°C under air atmosphere, respectively, compared with pure POM. Furthermore, the differential scanning calorimetry (DSC) analysis showed that reactable nano-SiO2had a good heterogeneous nucleation capability in POM, and could increase crystallization temperature of POM, but surface structure of reactable nano-SiO2was not propitious to the growth of POM crystals, accordingly leading to the decreasing crystallinity of composites.


2012 ◽  
Vol 472-475 ◽  
pp. 1937-1940
Author(s):  
Dong Yan Ren ◽  
Xiao Hong Li ◽  
Zhi Hua Li

Polyurethane-modified epoxy resin was prepared with Polyurethane prepolymer(PUP). The effects of the PUP content and epoxy resin type on mechanical and thermal properties of materials were discussed. The results indicate that the tensile strength and impact strength of the material increase to maximum successively, and then decrease with the increasing addition of PUP. When the mass fraction of PUP was 15%, the tensile strength and the impact strength of materials were all the best. There were significant differences in mechanical and thermal properties of material for different epoxy, and the best results were cured epoxy TDE-85.


2010 ◽  
Vol 150-151 ◽  
pp. 406-409
Author(s):  
Wen Lei ◽  
Xiao Yan Ding ◽  
Chi Xu

Polypropylene and wood flour were used as raw materials,maleic anhydride grafted polypropylene(MAPP) as compatibilizing agent, wood-plastic composite(WPC) was prepared by compression molding process. The effects of the content of MAPP on the mechanical and thermal properties of WPC were investigated. The results show that, with the increase of the content of MAPP, both the tensile and flexural strengths of WPC will increase, and the impact strength of WPC increases first, then decreases, and the impact strength reaches the maximum of 1.18kJ/m2 when the content of MAPP is 4%,which is 76.7% increased from that of the composite without MAPP. Each composite has an obvious heat-absorption peak when melted during 140-170 and the melting enthalpy of WPC increases with the content of MAPP, the melting procedures of all the composites are quite similar with one another. Application of MAPP can improve the thermal stability of WPC


Author(s):  
Mayank Agarwal

Abstract: This work investigates the mechanical properties (Tensile Strength & Impact Strength) and thermal properties (Thermal conductivity & diffusivity) of a natural fiber composite that includes banana fiber as reinforcement in epoxy (LY 556) matrix as the base material with the addition of silicon carbide particles by 5% and 10% by weight. This Banana Fiber Reinforced Epoxy Composite (BFREC) prepared by hand lay-up technique. After curing for a sufficient period, samples taken out and tested. The results suggest that on increasing SiC wt% in the matrix, there is enhancement of its tensile strength, impact strength, and thermal conductivity. Bulk density also increases while thermal diffusivity decreases. Due to low density as compared to metals, improved tensile and impact strength and low elongation at break of banana fibers, BFREC composite with SiC have very good potential use in the various sectors. Keywords: Banana fiber, SiC, hand layup technique, mechanical characterization, thermal conductivity, thermal diffusivity


2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.


2011 ◽  
Vol 45 (26) ◽  
pp. 2811-2816 ◽  
Author(s):  
Yihe Zhang ◽  
Anzhen Zhang ◽  
Zhichao Zhen ◽  
Fengzhu Lv ◽  
Paul K. Chu ◽  
...  

Polypropylene (PP) based composites containing 0, 5, 10, 15, 20, 30, and 50 wt% red mud are granulated by twin-screw extrusion and injection molding. Their mechanical properties such as tensile strength, flexural strength and modulus, impact strength, and thermal properties are determined. After filling with red mud, the flexural strength and modulus, thermal deformation temperature, and Vicat softening temperature increase, whereas the impact strength decreases with increasing red mud contents. The maximum tensile strength is observed from the PP doped with 15 wt% red mud. Scanning electron microscopy (SEM) is used to investigate the dispersion of red mud in the PP matrix.


2021 ◽  
Author(s):  
Tianran Chen

In this work, TLCP and GF reinforced PP have been recycled and TLCP/PP demonstrates superior recyclability over GF/PP due to the generation of fibrils during mold filling steps. The fiber shortening has a major impact on mechanical properties of GF/PP, which is induced by repeated injection molding and grinding. The thermal properties of TLCP/PP and GF/PP have been analyzed by DSC. The results show that injection molding and grinding does not impact the glass transition temperature, melting temperature and crystallinity of recycled composites.In continuation of this work, the influence of mechanical recycling on rheological, thermal stability and thermo-mechanical properties will be analyzed in order to gain full understanding about the impact of recycling on the various properties of TLCP and GF composites.


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