Filler In Polypropylene Composites Research Articles

Bioinspired surface modification of mussel shells and their application as a biogenic filler in polypropylene composites

This study explores the potential of mussel shells (MS) as biogenic fillers in polymer composites. The chemical composition and crystal structures of MS were characterised. To improve MS filler dispersion and adhesion within a polypropylene (PP) matrix, three surface modification methods were evaluated: polydopamine (PDA) coating, maleic anhydride-grafted polypropylene (MAPP) modification, and PDA/MAPP co-modification. The PDA coating, inspired by the adhesive properties of mussel foot proteins, successfully functionalized the MS surface, as confirmed by X-ray photoelectron spectroscopy (XPS). Thermodynamic analysis, based on contact angle measurements, revealed that MAPP and PDA/MAPP modifications reduced surface energies and potential energy differences. These changes enhanced filler dispersion and interfacial bonding by increasing hydrophobicity and reducing agglomeration in the PP matrix. Consequently, PP composites with 20% PDA/MAPP-modified MS fillers exhibited a 2.9% increase in tensile strength and a 7.5% increase in flexural strength compared to neat PP. Scanning electron microscopy (SEM) also showed reduced filler-matrix debonding and fewer voids. The proposed mechanism attributes these macroscopic property enhancements to the ability of the PDA coating to facilitate chemical and hydrogen bonding between MS fillers and MAPP.

Feasibility Study of Chemical Treatments on Sorghum Fibres for Compatibility Enhancement in Polypropylene Composites

Polypropylene (PP) is one of the biggest petro-polymers, which is used in very wide application nowadays. The environment problem due to materials such as plastics having very long time degradability, and critical petroleum sources have promoted some studies to empowerment of natural resources such as natural fibres for substituting or at least modifying petro-polymers. Because of biodegradability obtained from natural source, sorghum fibers are interesting to be used as filler in PP composites, despite of weak compatibility between them. Surface modification on the sorghum fibers through alkalinization prior to acetylation was aimed to improve the fiber compatibility to PP. The treatments were expected to substitute hydroxyl group in the sorghum fibers, into acetic ester group in order to increase their hydrophobicity as the fillers. Moreover, the treatments were able to unbundle single fibers into micro-fibrillated cellulose (MFC) fibres with increase in crystallinity index. Usage of this MFC fiber as filler in PP leads to improvement of the composite performances such as thermal properties. In this study, Fourier Transformation Infra-Red (FTIR) Spectroscopy, X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscope (FE-SEM) were used to evaluate the performances of the Sorghum fibers after the treatments and as the filler in the Sorghum fibers/PP composites. The experimental results showed the MFC fibers as the smallest sizes in 5.0 microns and the highest crystallinity index up to 79.1 %, obtained from alkalinization with 2.5 M NaOH prior to acetylation with 17.4 M CH3COOH and the glacial (CH3CO2)2. Compatibility study of the treated Sorghum fibers on PP shows an improvement indicated by a strong interaction between the fibers and PP on morphology observation, increase in melting point of PP from 163.4°C (using virgin Shorgum fibers) into 163.6°C (using treated Sorghum fibers) in DSC measurements.

The Utilisability of Ground Hazelnut Shell as Filler in Polypropylene Composites

The Utilisability of Ground Hazelnut Shell as Filler in Polypropylene Composites

Study and evaluation of dispersion of polyhedral oligomeric silsesquioxane and silica filler in polypropylene composites

Various methods were used for evaluation of homogeneity of polypropylene (PP) matrix composites with octakis([n‐octyl]dimethylsiloxy)octasilsesquioxane, octakis([n‐octadecyl]dimethylsiloxy)octasilsesquioxane, and silica (SiO2) fillers. The filler dispersion was determined on the basis of the results from the wide‐angle X‐ray scattering (WAXS) analysis, from the tests of selected mechanical properties, from scanning electron microscopy (SEM) with energy dispersive X‐ray spectroscopy and from the decomposable entropic descriptor method. The use of different methods allowed to evaluate homogeneity of PP composites on various levels and with different precisions. The dispersion degree was found to be mostly depended on the kind and amount of the filler used. The presence of long n‐alkyl chain substituents in POSS molecules greatly improved the level of filler dispersion in the polymer matrix in comparison to silica which was visually assessed by SEM. The WAXS method revealed the formation of filler aggregates in the PP matrix which influenced the structural characteristic of PP composites and changed the mechanical properties of those materials. However, the decomposable entropic descriptor method provided the possibility of quantitative and the most objective estimation of homogeneity of the obtained composite materials. POLYM. COMPOS., 40:1354–1364, 2019. © 2018 Society of Plastics Engineers

A new approach for evaluating the sustainability of raw materials substitution based on embodied energy and the CO2 footprint

The aim of this paper is to propose a simplified method of quantifying the environmental sustainability of raw materials substitution. This method is based on the use of two parameters that account for the energies and emissions involved in the formation of a material. The embodied energy and CO2 footprint are used to define a SUB-RAW index, which is used to compare the environmental performances of selected materials. This method is applied to a real case of stabilized municipal solid waste incineration fly ash using COSMOS (acronym of COlloidal Silica Medium to Obtain Safe inert) technology. The collected COSMOS material can substitute for natural resources (e.g., calcite and talc) as filler in polypropylene composites. This recovered material shows a mean embodied energy of 0.82 MJ/kg and mean CO2 footprint of 0.02 kg/kg. The SUB-RAW index, which is very close to zero when comparing COSMOS and calcite, establishes two materials’ equivalence regarding the energies and emissions involved in their production.

Evaluation of Waste from Aluminum Industry as Filler in Polypropylene Composites

White aluminum (Al) dross is the waste or by-product generated from the smelting of Al. Improper disposal of this waste will affect the sustainability of the environment. This study was aimed at investigating the feasibility of Al dross as a thermoplastic filler. Various content of Al dross (10–40 wt.%) was blended with polypropylene (PP) using an extruder. An improvement in thermal and flame resistance properties was evident, which was associated with the presence of aluminum hydroxide elements in Al dross as revealed from x-ray diffraction analysis. It was shown that the higher Al dross content in PP did cause the composites to possess high stiffness and low crystallinity. An advantage in wear properties further showed that the Al dross can be used as a filler for thermoplastics.

Acacia bark residues as filler in polypropylene composites

Large amounts of acacia bark residues are produced each day after tannin extraction with hot water, being generally burned. This by-product was chemically characterized and used as filler in polypropylene (PP) composites, considering different particle sizes and concentrations. The materials produced by melt blending had their mechanical and thermal properties evaluated. It was verified that, even containing a significant amount of extractable compounds, the acacia bark particles can produce PP composites with higher impact properties, higher crystallization temperature and higher degradation temperature in comparison to the polymer matrix.

Effect of Process Parameters on Mechanical Properties of Rice Husk Polypropylene Composites

Abstract Low density, easy of availability, less abrasive and biodegradable nature of lignocellulosic materials emphasized their usage for development of thermoplastic composites based on Rice Husk and Polypropylene (RHPP). Mechanical properties of RHPP composites such as tensile, impact strength decreases by the addition of rice husk, preheating of rice husk and its proper size is essential for its effective use as filler in polypropylene composites. Improvement in tensile, impact, hardness and abrasion resistance is possible by adding compatibiliser and reduction of cooling time. Impact strength of the composite increase with temperature, optimum temperature for obtaining good tensile, hardness and abrasion is 200°C. RHPP Composites thus prepared have potential for applications in building and automobile industries.

Rice husk as reinforcing filler in polypropylene composites

Commodity plastics such as polypropylene can be reinforced with lignocellulosic materials such as rice husk, available in the environment in abundance. Bonding between the polymer and rice husk can be improved by proper selection of compatibilizer or coupling agents. Thermoplastic composites thus prepared have potential applications in automotive industries and as good building material.

Preliminary Study on Application of Bentonite as a Filler in Polypropylene Composites

The effect of filler loading on mechanical, thermal, water absorption, and morphological properties of bentonite-filled polypropylene has been studied. Polypropylene composites of different filler loading were compounded by using a Polydrive Thermo Haake with Rheomix R600. The temperature and the rotor speed used were 180°C and 50 rpm, respectively. The mixing torque recorded increases with increasing filler loading. It also was found that the value of the tensile strength, impact strength, and elongation at break decreases with increasing filler loading. Contrast increments in flexural and tensile modulus were observed as loading of bentonite increases. Morphological investigation by using scanning electron microscopy revealed that the reduction in tensile strength, impact strength, and elongation at break were due to agglomeration of bentonite particle, particularly for composite with high bentonite loading. The thermal properties were investigated by using thermogravimetric analysis. Thermogravimetric analysis showed decreasing degradation temperatures of composites with increasing bentonite loading. On the other hand, the percentage of water absorption showed an increase with increasing filler loading.