Study and characterisation of the post processing ageing of sago pith waste biocomposites

This paper reports the post-processing ageing phenomena of thermoplastic sago starch (TPS) and plasticised sago pith waste (SPW), which were processed using twin-screw extrusion and compression moulding techniques. Wide angle X-ray diffraction (XRD) analyses showed that after processing, starch molecules rearranged into VH-type (which was formed rapidly right post processing and concluded within 4 days) and B-type (which was formed slowly over a period of months) crystallites. Evidence from Fourier transform infrared spectroscopy (FTIR) analyses corroborated the 2-stage crystallisation process, which observed changes in peak styles and peak intensities (at 1043 and 1026 cm-1) and band-narrowing. Thermogravimetric analysis (TGA) studies showed that the thermal stability of plasticised SPW declined continuously for 90 days before gradual increments ensued. For all formulations tested, post-processing ageing led to drastic changes in the tensile strength (increased) and elongation at break (decreased). Glycerol and fibres restrained the retrogradation of starch molecules in TPS and SPW

Thermal, dynamic mechanical analysis and mechanical properties of polybutylene terephthalate/polyethylene terephthalate blends

Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and mechanical tests were conducted to characterize the properties of polybutylene terephthalate/polyethylene terephthalate (PBT/PET) blends. PBT and PET were blended at different PBT/PET ratios (80/20, 60/40, 40/60, 20/80) via twin screw extruder prior to injection molding. DSC characterization showed a single glass transition temperature for all PBT/PET blends indicating that the miscibility occurred in the amorphous region. From DMA results, loss modulus and tan δ also showed a single peak for all PBT/PET blends, confirming the DSC results. At room temperature, PBT/PET 20/80 has the highest storage modulus followed by PBT/PET 80/20 blend. PET has higher tensile strength, flexural strength, Young’s and flexural modulus than PBT but lower in elongation at break and impact strength. PBT/PET 80/20 blend has the highest tensile strength, flexural strength, elongation at break, and impact strength compared to other PBT/PET blends. PBT/PET 80/20 blend can be suggested as an optimum formulation with balanced mechanical properties in terms of stiffness and toughness

Mechanical and water absorption properties of poly(vinyl alcohol)/sago pith waste biocomposites

A series of blends of sago pith waste (SPW) and poly(vinyl alcohol) (PVA) were prepared. Mechanical and water absorption properties of the composites have been investigated. In this study, variable amounts of plasticized SPW (pSPW) and PVA (pPVA) were processed in the presence of glycerol as plasticizers. Composites were compression molded and evaluated. The addition of pSPW reduced the tensile properties of the composites, lowering the elongation and increasing Young’s modulus. The reduction in mechanical strength with the addition of pSPW was a general phenomenon due to the poor interfacial adhesion between the pPVA and Pspw, which can be proved by the scanning electron microscope observations. The percentage of water absorbed of the pPVA/pSPW biocomposites was higher than either the pPVA or pSPW alone while pSPW showed better water resistance compared to pPVA because of the restricted mobility exerted by the cellulose fibers. The incorporation of SPW into PVA decreased both the mechanical and water absorption properties

Influence of compounding methods on poly(vinyl) alcohol/sago pith waste biocomposites: mechanical and water absorption properties

Several methods of incorporating sago pith waste (SPW) into polyvinyl alcohol) (PVA) had been conducted: (i) dry blending (PVA/SPW/G), (ii) blending of SPW and pre-plasticized PVA (pPVAISPWlG) and (iii) blending of pre-plasticized of both PVA and SPW (pPVA/pSPW). The effect of the compounding method on the mechanical and water absorption properties were investigated. The addition of SPW into PVA greatly reduced the tensile strength and elongation at break. The tensile strength and elongation at break of PVA/SPW composites with identical geometry during compounding stage (powder/ powder and pellet/pellet), which were PVA/SPW/G and pPVA/pSPW yielded the highest value. The percentage of water absorbed by PVA/SPW/G (without pre-plasticization) was the highest, followed by pPVA/pSPW and pPVA/SPW/G

Use of natural pozzolanic material as partial replacement Ordinary Portland Cement (OPC) in concrete

Fly ash is a powder material of burned coal from thermal power stations which produces cementitious and pozzolanic material. Commonly use of fly ash in concrete for building construction contributes conducive environmental and also reduces the effect of pollutant in site project. Therefore, this study was conducted to investigate the use of fly ash as partial replacement of cement in concrete as a mean of producing more environmental friendly concrete. The content of fly ash as partial replacement of ordinary portland cement(OPC) is investigated by weight accordingly in range 0%(without fly ash), 10%, 20% and 30% for grade 25. The chemical composition of fly ash was determine using X-ray Fluorescence (XRF). The scanning electron microscope (SEM) was used to determine particle size, shape and texture of fly ash. The mix proportion of concrete was determine using mix design method according to British Standard. The workability of the fresh concrete mixture was evaluated using slump test while compressive strength of cubes concrete was evaluated at 7, 14, 28 and 56 days. A total of 48 cubes concrete with size 100mmx100mmx100mm were made. The optimum compressive strength at all ages of testing was obtained at 10% replacement. Workability decreased with an increased in replacement percentage of fly ash. The results therefore show that fly ash as pozzolanic materials can be used to partially replace ordinary portland cement in production of concrete

A review on nanocellulose and its application in producing aerogels

The existence abundant of cellulose in nature has drawn much attention from both academia and industry in recent years due to its specific properties such as biodegradability, thermal and chemical stability. In the past few years, nanocellulose aerogel, which possesses extremely low density, large open pores, and a high specific surface area, has been discovered by researchers as new polymer materials. In this review, basic important information about nanocellulose aerogel will be introduced such as the properties of the nanocellulose and its application in producing nanocellulose aerogel based on the previous research studies

Mechanical and water absorption properties of poly(vinyl alcohol)/sago with waste biocomposites

A series of blends of sago pith waste (SPW) and poly(vinyl alcohol) (PVA) were prepared. Mechanical and water absorption properties of the composites have been investigated. In this study, variable amounts of plasticized SPW (pSPW) and PVA (pPVA) were processed in the presence of glycerol as plasticizers. Composites were compression molded and evaluated. The addition of pSPW reduced the tensile properties of the composites, lowering the elongation and increasing Young’s modulus. The reduction in mechanical strength with the addition of pSPW was a general phenomenon due to the poor interfacial adhesion between the pPVA and Pspw, which can be proved by the scanning electron microscope observations. The percentage of water absorbed of the pPVA/pSPW biocomposites was higher than either the pPVA or pSPW alone while pSPW showed better water resistance compared to pPVA because of the restricted mobility exerted by the cellulose fibers. The incorporation of SPW into PVA decreased both the mechanical and water absorption properties

Characterisation of sago pith waste and its composites

Sago pith waste (SPW), a fibrous residue resulted from the sago starch extraction process, was characterised in terms of moisture content (82%) and starch content (62%, dry weight basis). The dried and ground SPW was irregular in shape and has a CE diameter of 29.41μm, similar to that of pure sago starch (28.43μm). SEM micrograph showed that SPW is a mixture which consists of sago starch and fibre, verified by FTIR spectrum and XRD diffractogram observed from peaks which were attributed to sago starch and SPW fibre. With glycerol and water as plasticisers, SPW was then plasticised successfully to form a natural fibre filled thermoplastic starch composite using a twin screw extruder in the presence of various quantities of glycerol. No synthetic polymer binder was added. Plasticisation led to the disruption of the original C-type crystallinity of sago starch. However, VH and B type crystallinities were developed after processing as a result of the reorganisation of amylose, amylose-lipid complex (very fast) and amylopectin chains (slow)