Search

Reinforcement with natural fibres is a common method to improve impact properties of poly(lactic acid) (PLA). In this study, composites made from PLA and bamboo particles were melt-compounded in a twin-screw extruder and formed by compression moulding. Tensile, flexural, and impact tests were conducted. Particle size (A), particle loading (B), screw speed (C), and die temperature (D) were varied at three levels. Tensile strength and modulus, flexural strength and modulus, and impact strength were the response variables. The experiment design was based on Taguchi's (L9) orthogonal array. Through variance analysis, the particle loading was found to be the dominant factor influencing the mechanical properties, followed by die temperature. The optimum parameters were validated with a confirmation test. The results showed a noticeable improvement of impact properties compared to neat PLA by 55%, without compromising tensile and flexural properties. Flexural strength, flexural modulus, and tensile modulus of the composites were greater than that of pure PLA. However, only tensile strength was reduced by about 28% compared to pure PLA. Importantly, the DOE method with maximizing the desirability properties was found to be an effective systematic approach to identify an optimal parameter setting of the extrusion moulding process. [ABSTRACT FROM AUTHOR]

Rule of mixture models are usually used in the tensile properties prediction of polymer composites reinforced with synthetic fibres. They are less utilized for natural fibre/polymer composites due to natural fibres physical and mechanical properties variability which reduces rule of mixture model's prediction values accuracy compared to the experimental values. This had led to studies conducted by various researchers to improve the existing rule of mixture models to give a better reflection of the true natural fibres properties and enhance the rule of mixture models prediction accuracy. In this paper, rule of mixture model's utilization includes the existing rule of mixture models as well as proposed rule of mixture models which have one or more factors incorporated into existing rule of mixture models for natural fibre/polymer composites tensile properties prediction are reviewed. [ABSTRACT FROM AUTHOR]

The term hydrocolloid generally refers to substances that form gels or provide viscous dispersion in the presence of water. Alginate, agar, and carrageenan are three commercially valuable hydrocolloids derived from certain brown and red seaweed and each has their distinct physicochemical properties (i.e. functional and bioactive). Various applications of these seaweed hydrocolloids as thickeners, stabilizers, coagulants and salves (in the wound and burn dressings) and materials to produce bio-medical impressions in the food, pharmaceutical, and biotechnology industries are highlighted in this review. Although the existing industrial methods of extraction for these seaweed hydrocolloids are well-established, still growing demand has exposed certain limitations of those methods, notably efficiency and product consistency. In order to achieve targeted hydrocolloids for specific purposes and functionalities, some novel and green extraction methods have also been proposed and discussed. Microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), supercritical fluid extraction (SFE), pressurized solvent extractions (PSE), reactive extrusion and photobleaching process are selectively presented as highly promising candidates that can avoid the use of chemicals and provide novel means of access to seaweed hydrocolloids with both economic and environmental benefits. However, this review does not provide the 'best' method or procedure as many are still under development. Hence, the review gives 'food for thought'as to new processes which might be adopted industrially and concluded that further research is required in order to contribute additional new knowledge and refinement to this field of study. [ABSTRACT FROM AUTHOR]

Microcrystalline cellulose (MCC) isolated from cheap, fast-growing and abundant accessible Sacred Bali bamboo (Schizostachyum brachycladum) was utilized as reinforcement material in the seaweed-based composite film. Isolation of MCC was carried out by using a combination of pulping, bleaching and acid hydrolysis process. This study emphasized on the feasibility of MCC production from Sacred Bali bamboo by studying its properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The commercial-MCC (CMCC) was used as reference material. Results showed that the production yield, moisture content (MC) and fiber length of bamboo-MCC (BMCC) were 83.37±1.48%, 4.50±0.5%, and 0.47±0.02 mm, respectively. According to the chemical analysis by FTIR, both lignin and hemicellulose were completely removed from BMCC, and thus, improved the crystallinity (78%) and thermal stability (≈325 oC) of BMCC. This study also revealed that MCC produced from Sacred Bali bamboo demonstrated strong mechanical reinforcement effect in the seaweed-based film. Hence, Sacred Bali bamboo-MCC could be used as reinforcement material in the polymer. [ABSTRACT FROM AUTHOR]

Seaweed and cellulose are promising natural polymers. This article reviews the basic information and recent developments of both seaweed and cellulose biopolymer materials as well as analyses the feasible formation of seaweed/cellulose composite films. Seaweed and cellulose both exhibit interesting film-forming properties. Nevertheless, seaweed has poor water vapour barrier and mechanical properties, whereas cellulose is neither meltable nor soluble in water or common organic solvents due to its highly crystalline structure. Therefore, modification of these hydrocolloids has been done to exploit their useful properties. Blending of biopolymers is a must recommended approach to improve the desired characteristics. From the review, seaweed is well compatible with cellulose, which possesses excellent mechanical strength and water resistance properties. Moreover, seaweed/cellulose composite films can prolong a product's shelf life while maintaining its biodegradability. Additionally, the films show potential in contributing to the bioeconomy. In order to widen seaweed and cellulose in biocomposite application across various industries, some of the viewpoints are highlighted to be focused for future developments and applications. [ABSTRACT FROM AUTHOR]

In this study, nanocellulose whiskers (NCW) from oil palm empty fruit bunches (OPEFB) were used as reinforcement phase in polylactid acid (PLA). Two techniques were employed to isolate the NCW from OPEFB microcrystalline cellulose (OPEFB-MCC); chemical swelling with DMAc containing 0.5% LiCl to generate the NCW and acid hydrolysis with 64% H2SO4 to generate the NCW-S. The atomic force microscopy showed that the isolated NCW and NCW-S are in nanoscale dimension and displayed an individual rod-like structure. The fillers were then incorporated in PLA matrix at different loadings (1, 3, and 5 parts per hundred resin (phr)) to produce P-NCW and P-NCW-S nanocomposites via solution casting technique. The mechanical properties of the developed nanocomposites were investigated by means of tensile test. The results showed that the tensile strength of nanocomposites increased by 84% and 64% for the NCW and NCW-S reinforced PLA nanocomposites, respectively. The Young’s modulus of nanocomposites increased linearly with the fillers loading. Expectedly, the percent elongation at break was impacted negatively as it decreased with fillers loading. The thermogravimetric analysis showed that the decomposition temperatures (T10, T50 and Tmax) of P-NCW were higher than neat PLA. In the case of P-NCW-S however, the thermal stability decreased with the additional of NCW-S. [ABSTRACT FROM AUTHOR]

Acid hydrolysis method was used to isolate microcrystalline cellulose (MCC) from oil palm empty fruit bunches (OPEFB) total chlorine free bleached pulp. The derived MCC was incorporated into polylactic acid (PLA) using solution casting technique in order to produce PLA/MCC composites. The chemical structure of the cellulose fragments remains unaltered as demonstrated by Fourier transform infrared spectroscopy despite acid hydrolysis. X-ray diffraction showed that the MCC has a cellulose I polymorph with 87% crystallinity index. The addition of MCC into PLA enhanced not only the thermal stability but also the Young’s modulus of the PLA/MCC composites by approximately 30% at 5 phr MCC contents compared to pure PLA. However a decrease in tensile strength and elongation at break of the PLA/MCC composites were observed due to the poor dispersion of MCC in the PLA matrix. [ABSTRACT FROM AUTHOR]

Petroleum based thermoplastics are widely used in a range of applications, particularly in packaging. However, their usage has resulted in soaring pollutant emissions. Thus, researchers have been driven to seek environmentally friendly alternative packaging materials which are recyclable as well as biodegradable. Due to the excellent mechanical properties of natural fibres, they have been extensively used to reinforce biopolymers to produce biodegradable composites. A detailed understanding of the properties of such composite materials is vital for assessing their applicability to various products. The present review discusses several functional properties related to packaging applications in order to explore the potential of bamboo fibre fabric-poly (lactic) acid composites for packaging applications. Physical properties, heat deflection temperature, impact resistance, recyclability and biodegradability are important functional properties of packaging materials. In this review, we will also comprehensively discuss the chronological events and applications of natural fibre biopolymer composites. [ABSTRACT FROM AUTHOR]

The present study was conducted to determine the recyclability and biodegradability of bamboo fabric-reinforced poly(lactic) acid (BF-PLA) composites for sustainable packaging. BF-PLA composite was recycled through the granulation, extrusion, pelletization and injection processes. Subsequently, mechanical properties (tensile, flexural and impact strength), thermal stability and the morphological appearance of recycled BF-PLA composites were determined and compared to BF-PLA composite (initial materials) and virgin PLA. It was observed that the BF-PLA composites had the adequate mechanical rigidity and thermal stability to be recycled and reused. Moreover, the biodegradability of BF-PLA composite was evaluated in controlled and real composting conditions, and the rate of biodegradability of BF-PLA composites was compared to the virgin PLA. Morphological and thermal characteristics of the biodegradable BF-PLA and virgin PLA were obtained by using environment scanning electron microscopy (ESEM) and differential scanning calorimetry (DSC), respectively. The first order decay rate was found to be 0.0278 and 0.0151 day-1 in a controlled composting condition and 0.0008 and 0.0009 day-1 in real composting conditions for virgin PLA and BF-PLA composite, respectively. Results indicate that the reinforcement of bamboo fabric in PLA matrix minimizes the degradation rate of BF-PLA composite. Thus, BF-PLA composite has the potential to be used in product packaging for providing sustainable packaging. [ABSTRACT FROM AUTHOR]

gricultural wastes, oil palm trunk (OPT) veneer and oil palm empty fruit bunch (EFB) mat were used for the preparation of hybridized plywood using 250 and 450 g/m of urea formaldehyde (UF) as gluing agent. The mechanical (flexural strength, flexural modulus, screw withdrawal, shear strength), physical (density, water absorption, thickness swelling and delamination) and thermal (TGA) properties of the biocomposites were studied. Images taken with a scanning electron micrograph (SEM) indicated an improvement in the fiber-matrix bonding for the laminated panel glued with 450 g/m of UF. [ABSTRACT FROM AUTHOR]

In the present study, microcrystalline cellulose (MCC) was isolated from oil palm fronds (OPF) using chemo-mechanical process. Wherein, alkaline hydrogen peroxide (AHP) was utilized to extract OPF fibre at different AHP concentrations. The OPF pulp fibre was then bleached with acidified sodium chlorite solution followed by the acid hydrolysis using hydrochloric acid. Several analytical methods were conducted to determine the influence of AHP concentration on thermal properties, morphological properties, microscopic and crystalline behaviour of isolated MCC. Results showed that the MCC extracted from OPF fibres had fibre diameters of 7.55-9.11nm. X-ray diffraction (XRD) analyses revealed that the obtained microcrystalline fibre had both celluloses I and cellulose II polymorphs structure, depending on the AHP concentrations. The Fourier transmission infrared (FTIR) analyses showed that the AHP pre-hydrolysis was successfully removed hemicelluloses and lignin from the OPF fibre. The crystallinity of the MCC was increased with the AHP concentrations. The degradation temperature of MCC was about 300°C. The finding of the present study showed that pre-treatment process potentially influenced the quality of the isolation of MCC from oil palm fronds., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Considering its widespread usage in various fields, such as food, pharmaceutical, medical, cosmetic and polymer composites industries, microcrystalline cellulose (MCC) is becoming impellent due to increasing demand of alternatives to non-renewable and scarce fossil materials. Although it still suffers from some drawbacks, MCC has recently gained more interest owing to its renewability, non-toxicity, economic value, biodegradability, high mechanical properties, high surface area and biocompatibility. New sources, new isolation processes, and new treatments are currently under development to satisfy the increasing demand of producing new types of MCC-based materials on an industrial scale. Therefore, this review assembles the current knowledge on the isolation of MCC from different sources using various procedures, its characterization, and its application in bio-composites. Challenges and future opportunities of MCC-based composites are discussed as well as obstacles remaining for their extensive uses., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The present study sheds light on the physical and chemical characteristics of microcrystalline cellulose (MCC) isolated from oil palm fronds (OPF) pulps. It was found that the OPF MCC was identified as cellulose II polymorph, with higher crystallinity index than OPF α-cellulose (CrI OPFMCC : 71%>CrI OPFα-cellulose : 47%). This indicates that the acid hydrolysis allows the production of cellulose that is highly crystalline. BET surface area of OPF MCC was found to be higher than OPF α-cellulose (S BETOPFMCC : 5.64m 2 g -1 >S BETOPFα-cellulose :Q a 0 2.04m 2 g -1 ), which corroborates their potential as an adsorbent. In batch adsorption studies, it was observed that the experimental data fit well with Langmuir adsorption isotherm in comparison to Freundlich isotherm. The monolayer adsorption capacity (Q a 0 ) of OPF MCC was found to be around 51.811mgg -1 and the experimental data fitted well to pseudo-second-order kinetic model., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this work, polylactic acid (PLA) reinforced cellulose nanowhiskers (CNW) were prepared through solution casting technique. The CNW was first isolated from oil palm empty fruit bunch microcrystalline cellulose (OPEFB-MCC) by using 64% H2SO4 and was designated as CNW-S. The optical microscopy revealed that the large particle of OPEFB-MCC has been broken down by the hydrolysis treatment. The atomic force microscopy confirmed that the CNW-S obtained is in nanoscale dimension and appeared in individual rod-like character. The produced CNW-S was then incorporated with PLA at 1, 3, and 5 parts per hundred (phr) resins for the PLA-CNW-S nanocomposite production. The synthesized nanocomposites were then characterized by a mean of tensile properties and thermal stability. Interestingly to note that incorporating of 3 phr/CNW-S in PLA improved the tensile strength by 61%. Also, CNW-S loading showed a positive impact on the Young's modulus of PLA. The elongation at break (Eb) of nanocomposites, however, decreased with the addition of CNW-S. Field emission scanning electron microscopy and transmission electron microscopy revealed that the CNW-S dispersed well in PLA at lower filler loading before it started to agglomerate at higher CNW-S loading (5phr). The DSC analysis of the nanocomposites obtained showed that Tg,Tcc and Tm values of PLA were improved with CNW-S loading. The TGA analysis however, revealed that incopreated CNW-S in PLA effect the thermal stability (T10,T50 and Tmax) of nanocomposite, where it decrease linearly with CNW-S loading., (Copyright © 2016 Elsevier B.V. All rights reserved.)