Investigation of the Mechanical and Liquid Absorption Properties of a Rice Straw-Based Composite for Ayurvedic Treatment Tables

Managing rice crop stubble is one of the major challenges witnessed in the agricultural sector. This work attempts to investigate the physical, mechanical, and liquid absorption properties of rice straw (RS)-reinforced polymer composite for assessing its suitability to use as an ayurvedic treatment table. This material is expected to be an alternative for wooden-based ayurvedic treatment tables. The results showed that the addition of rice straw particles (RSp) up to 60% volume in epoxy reduced the density of the composite material by 46.20% and the hardness by 15.69%. The maximum tensile and flexural strength of the RSp composite was 17.53 MPa and 43.23 MPa, respectively. The scanning electron microscopy (SEM) analysis showed deposits of silica in the form of phytoliths in various size and shapes on the outer surface of RS. The study also revealed that the water absorption rate (WA) was less than 7.8% for the test samples with 45% volume of RSp. Interestingly the test samples showed greater resistance to the absorption of Kottakal Dhanvantaram Thailam (<2%). In addition, the developed samples showed resistance towards bacterial and fungal growth under the exposure of treatment oils and water.

Tensile and Liquid Absorption Properties of Polyester-based Composites as Alternative Marble Materials

Three polyester-based composite materials were prepared with different volume fractions of three types of fillers (i.e. cement, gypsum and limestone) with the aim of improving the tensile and liquid absorption properties of the former for the synthetic marble industry. The tensile strength, modulus of elasticity, toughness, ductility and liquid absorption percentage of the composites were characterized. Results revealed an increase in the modulus of elasticity, tensile strength and toughness of all prepared composites, as well as a decrease in their ductility, with increasing filler amount. The liquid absorption values of all composites increased with increasing filler content. The composites were able to absorb water extensively but absorbed benzene, kerosene and gasoil minimally.

Transfer and Friction Characteristics of Sports Socks Fabrics Made of Synthetic Fibres in Different Structures

Sports socks fabrics produced from polyester, polypropylene, their modified forms Thermocool®, Polycolon®, in three different structures (single jersey, piquet, terry) were investigated for their skin-fabric friction, permeability (air and water vapour), liquid absorption and transfer (absorbency, immersion, absorption capacity, wetback and drying) properties. According to the results, the effect of structure is dominant for frictional characteristics but focusing on the material, polypropylene created a bulkier and lighter structure with lower friction coeffi¬cients, an advantage for sports socks. The effect of structure is greater than the material also for some thermal comfort parameters, e.g. air permeability and absorbency. Focusing on materials, besides their better liquid transfer characteristics, modified forms of both fibres had worse performances for air permeability and absor¬bency compared to their standard forms. Absorption capacity, wetback and drying performances were related to fabric density besides the polyester’s higher regain capacity. While Polycolon® had superiority for wetback performance against standard polypropylene, this was not the case for Thermocool®; however, both modified materials showed apparent superiority for drying periods. Piquet structures were advantageous for absorption capacity and wetback performances for polypropylene. For sports socks parts, specific needs can be met by changing the fabric structure. Considering the materials, polypropylene and Polycolon® can be recommended for both thermal and tactile aspects.

Preparation of Electrospun Polyvinyl Alcohol/Nanocellulose Composite Film and Evaluation of Its Biomedical Performance

Using polyvinyl alcohol (PVA) and nanocellulose (NC) as raw materials, PVA/NC nanofiber membranes were prepared by electrospinning. The hydrogen bonding, crystalline properties and microscopic appearance of PVA/NC membranes with different NC contents were characterized. The mechanical properties, liquid absorption and cytotoxicity of the nanofiber membrane were evaluated. The results show that the free hydroxyl group of the PVA/NC nanofiber membranes have a maximum value of 9% at a mass fraction of 6% NC. The crystallinity of the PVA/NC nanofiber membranes and the average diameter of the nanofibers decreased and then increased as the NC content increased, with a minimum value of 38.23% and 272.03 nm, respectively, at 6% NC content. At this time, the contact angle was the smallest. The maximum strength of the PVA/NC nanofiber membranes is 75.8% higher than that of the PVA membrane at 2% NC content. With increasing NC content, the absorption of water, PBS sustained-release suspensions and artificial blood by PVA/NC nanofiber membranes increases. Cytotoxicity tests have shown that PVA/NC nanofiber membranes are non-toxic, have good cytocompatibility and are expected to be used in the field of medical dressings.

Effects of soaking in water, base oil, ionic liquid and grease of an epoxy/UHMWPE/MoS2 composite on mechanical and tribological properties

Liquid absorption and tribological studies of epoxy-based composite with ultra-high molecular weight polyethylene (UHMWPE) and MoS2, sliding against steel were conducted. Composites, as coating and as a bulk, were soaked in water, base oil, ionic liquid and lithium-based grease for different intervals of days or months. Liquid weight% gain was more in polar liquids when compared to non-polar. Coated composite soaked in grease for 10 days showed coefficient of friction of 0.08 with wear-life of more than 1 million cycles and wear rate of 1.7×10−8 mm3/Nm. Bulk polymer composite soaked in grease for 180 days provided the least coefficient of friction of 0.06 and specific wear rate of 2.60×10−7 mm3/Nm.

High-Permeability Wood with Microwave Remodeling Structure

This paper presents the development of a microwave puffed wood (MPW) with novel and unique structural features in its internal structure that are based on natural wood (NW). The focus of the research was on the comprehensive visualization of the structural characteristics of MPW from the macroscopic to the microscopic scale followed by an exploration of its impregnation capabilities. The results showed that the volume of MPW increased by about 9% compared to NW due to the presence of a large number of cracked cavities. The CT images indicated that there was a significant difference between the macroscopic cracks produced by microwave processing and the natural cracks in the wood. The mercury intrusion test results showed that macro-pores increased while the micro-pores decreased in the MPW compared to in the NW. The MPW showed good fluid permeability and liquid absorption performance. The phenolic resin penetration rate of the MPW was about 20 times that of the NW, and the material absorption was more than 2 times that of the NW. The crack space enabled the MPW to serve as a fluid transportation and a storage warehouse. MPW is a super container based on natural materials. It has broad potential in more fields, such as in wood composite materials.