Characteristics of a silk fibre reinforced biodegradable plastic

Silk fibre is one kind of well recognized animal fibres for bio-medical engineering and surgical operation applications because of its biocompatible and bio-resorbable properties. Recently, the use of silk fibre as reinforcement for some bio-polymers to enhance the stiffnesses of scaffolds and bone fixators has been a hot research topic. However, their mechanical and biodegradable properties have not yet been fully understood by many researchers, scientists and bio-medical engineers although these properties would govern the usefulness of resultant products. In this paper, a study on the mechanical properties and bio-degradability of silk fibre reinforced Poly (lactic-acid) (PLA) composites is conducted. It has been found that the Young’s modulus and flexural modulus of the composites increased with the use of silk fibre reinforcement while their tensile and flexural strengths decreased. This phenomenon is attributed to the disruption of inter- and intra-molecular bonding on the silk fibre with PLA during the mixing process, and consequent reduction of the silk fibre strength. Moreover, bio-degradability tests showed that the hydrophilic properties of the silk may alter the biodegradation properties of the composites compared to that of a pristine PLA sample

Variable presentations of dengue fever with diagnostic dilemma: A case series

Dengue is a viral fever in humans which is caused by 4 serotypes of the flavivirus. It is spread by the bite of the infected Aedes mosquitoes. The acute febrile illness is often associated with multisystem involvement with complications. The case series presented here depicts atypical manifestations of dengue which may present with hypoplastic anemia, hepatitis, pancreatitis, and encephalopathy. The cases were diagnosed based on history of dengue with subsequent persistence of pancytopenia, presence of hepatitis, pancreatitis, and encephalopathy with serological evidence of dengue and after ruling out other possible etiologies supported by laboratory evidence of investigations. The bone marrow revealed pancytopenia with hypocellular marrow causing hypoplastic anemia, transaminitis and rise of lipase and amylase with symptoms diagnosed hepatitis, pancreatitis, and finally impairment of consciousness with electroencephalogram proved encephalopathy. The importance of the case series lies in the fact that atypical manifestations may occur in dengue patients challenging the physicians and early detection may avoid unnecessary treatment and complications

Disposal Options of Bamboo Fabric-Reinforced Poly(Lactic) Acid Composites for Sustainable Packaging: Biodegradability and Recyclability

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

Green Composites Made of Bamboo Fabric and Poly (Lactic) Acid for Packaging Applications—A Review

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

Green Composites Made of Bamboo Fabric and Poly (Lactic) Acid for Packaging Applications—A Review

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

Investigation on the competing effects of clay dispersion and matrix plasticisation for polypropylene/clay nanocomposites. Part I: morphology and mechanical properties

The key compatibiliser role of maleated polypropylene (MAPP) to improve the clay dispersability has been explicitly addressed in the fabrication process and material characterisation of polypropylene (PP)/clay nanocomposites. However, its matrix plasticiser role, which has been rarely mentioned, could adversely influence the excellent mechanical properties of such nanocomposites, resulting from the homogeneous clay dispersion. PP/clay nanocomposites in the presence of MAPP were prepared by twin screw extrusion and subsequently injection moulded with three typical material formulations in fixed parametric settings: (1) weight ratio (WR) of clay and MAPP, WR = 1:2; (2) MAPP content of 6 wt% and (3) clay content of 5 wt%. The morphological structures and mechanical properties of PP/clay nanocomposites were examined by using X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and universal mechanical testing. The further improvement of mechanical properties was evidently hindered with very inconsiderable alteration of morphological structures in terms of the clay dispersion level. This observation could be ascribed to the change of MAPP role from a compatibiliser to a plasticiser because of its excessive amount used above a certain saturation level, which was found in the range of 3–6 wt% in MAPP contents for the enhancements of tensile and flexural properties of PP/clay nanocomposites

Investigation on the competing effects of clay dispersion and matrix plasticisation for polypropylene/clay nanocomposites. Part II: Crystalline structure and thermo-mechanical behaviour

In view of the structure–property relationship, the mechanical property enhancement of polypropylene (PP)/clay nanocomposites can also be associated with the alterations of their crystalline structures and behaviour in addition to the general interpretation of intercalation/exfoliation level and uniform dispersion of more rigid clay platelets with higher aspect ratios in the PP matrix. Wide-angle X-ray diffraction (WAXD) was utilised to evaluate the effects of clay content, maleated PP (MAPP) content (MAPP as the compatibiliser) on PP crystalline structures of nanocomposites. Furthermore, the melting and crystallisation behaviour of PP/clay nanocomposites was also investigated by conducting differential scanning calorimetry (DSC). The thermo-mechanical properties were characterised via dynamic mechanical thermal analysis (DMTA). It is observed that enhancement of mechanical properties are mainly affected by the preferred orientation of PP crystals, the growth of α-PP phase and effective nucleating agent role of additional clay while the excessive amount of MAPP becomes detrimental to these crucial aspects, which is also evidently revealed in DMTA measurements

Mechanical properties of an injected silk fibre reinforced PLA composite

Chopped silkworm silk fibres and Poly-lactic acid (PLA) were mixed to form a fully biodegradable thermoplastic composite. Injection moulding process was used to mix these constituents together at a controlled temperature range. The mechanical properties of the composite were examined through tensile and flexural property and Izod impact tests. It was found that the Young's and flexural moduli of the composite increased while their strengths and impact resistance decreased during the tests as compared with a PLA sample. Early fibre fractures observed from micrographs explain the reasons of enhanced moduli and reduction of strengths

Wool fabrics decorated with carbon-based conductive ink for low-voltage heaters

Smart textiles have extensively progressed in recent years and have expanded the potential scope and market of textiles, especially in areas of sensing, energy storage and heating. A great opportunity still exists to develop heaters based on natural fibre-based fabrics that are soft, light weight, and biodegradable. In this study, a simple, environmentally friendly, and scalable process to prepare highly conductive wool fabrics (CWFs) is reported. This multi-step process consists of stir coating and dip coating techniques using highly conductive ink based on graphene nanoplatelets (GNPs) and carbon black (CB) particles, followed by the cold-pressing process. Time-dependent temperature profiles and heat distribution analysis of the CWFs showed superior electrothermal performance to the heaters reported in the literature, reaching a surface temperature of more than 230 °C with a low applied voltage of 4.5 V (or an equivalent input power of ∼7.2 W). To demonstrate their potential application, the concept of a sandwich-structured and large size heating device was designed and the device was fabricated using a 3 × 3 array of CWFs