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More than 50% of the flame retardants used in the polymer and plastic industries are metal hydroxides. Among them, aluminum trihydroxide (ATH) is the most widely used due to its low toxicity and corrosiveness and its cost-effectiveness. The use of high-volume ATH in polymers reduces the mechanical properties. In this work, clay nanoparticles were added into epoxy/glass fiber/ATH hybrid composites to improve the mechanical and thermal properties of the composites. The effect of nano-clay content (1, 3, and 5 phr) on mechanical properties such as tensile and flexural strength and modulus, and thermal properties was investigated. Thermal properties were evaluated by Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). The result of mechanical tests showed that adding 3 phr of clay nanoparticles increases tensile and flexural strength by 10% and 9.2%, respectively. The flammability of the composites was measured in horizontal mode. The flammability results revealed that introducing 3 phr of nano-clay improves the flammability of the composites by 41%. [ABSTRACT FROM AUTHOR]

In this study, De Gennes's scaling theory was developed to evaluate the variation of distance-dependent thermal properties inside the polymer/particle interphase region based on the molecular characteristics of the polymer matrix and surface adsorption energy. Accordingly, the average thermal conduction coefficient of the region was predicted and used to approximate the overall thermal conductivity of the nanocomposite system. The physical characteristics of the nanoparticle clusters (e.g., size and content) were defined using a specific strategy based on the equilibrium between dispersion and cohesion energies during the preparation of the nanocomposite samples, via melt mixing. Maxwell's model was also developed and used to predict the thermal conduction coefficient of the polymer/nanoparticle system considering the determinative impact of the polymer/particle interphase region and aggregation/agglomeration phenomenon. It was found that the scaling parameter, defining the polymer/particle interaction strength, increased by almost 50% by increasing the compatibility. This also increased the thermal conductivity of the interphase from 1.401 (W.m-1.K-1) to 3.028 (W.m-1.K-1) in the samples containing compatible nanoparticles. The thermal conductivity of nanoparticle clusters decreased exponentially with increasing the number of involved nanoparticles. The maximum prediction error of the proposed model (6.9%) was 12% less than that of the original Maxwell's model. [ABSTRACT FROM AUTHOR]

A fabric touch tester is a novel instrument with fabric handling properties. Its principal advantage is that the device has integrated modules for compression, surface friction, and thermal and bending properties. This module integration simplifies the testing process, and provides an efficient measurement method, and a comprehensive physical index. This study focused on woven fabrics for dress shirts. The fabric samples comprised three groups with various yarn compositions – that is, cotton, polyester, and wool. Sample group 1 was composed of cotton, polyester, and blended yarns; sample group 2 mainly compared the effect of twist yarns on the fabric touch; and sample group 3 was composed of wool and blended yarns with polyester. The handling properties were assessed by compression work and the compression recovery rate for the compression attributes. The results revealed that fabric (T100p1) with high twist-level yarns had a higher value of compression work (242.56 gf*mm2), and the texture type may affect the compression characteristics more significantly than the blending ratio. The fabric touch tester can also distinguish small changes in the compression properties of samples (0.43–0.71), the maximum heat flux and surface roughness amplitude for the thermal and surface roughness properties. The results revealed that the maximum heat flux value of all the samples in this study was 1109 Wm−2, the sample C100 using pure cotton yarn had the highest maximum heat flux value (1270 Wm−2). Moreover, the sample W100 with 100% wool fiber yarn had the highest surface roughness amplitude in the warp direction (81 μm) and surface roughness amplitude in the weft direction (67 μm). Finally, the bending average rigidity was used to assess the bending performance of the fabric samples. These fabric touch tester indicators were applied to analyze the fabric handling characteristics of woven shirting fabrics, and perform cross-analysis among samples. [ABSTRACT FROM AUTHOR]

Composites synthesized from natural waste and recycled plastic is quite a promising and interesting field for scientists and polymer industries. In the present study, bio-composites based on agriculture residue Sesamum indicum L. and recycled-low density polyethylene were synthesized by extrusion and injection molding technique at a fiber loading of 10–40 wt%. Additionally, 3% of maleic anhydride grafted low density polyethylene was used as a compatibilizer. The prepared composites were irradiated at 25 kGy, 75 kGy and 125 kGy doses of gamma rays. The effects of different fiber content and gamma doses on mechanical properties were studied statistically by Design Expert software. Response surface methodology was employed to depict the interaction among various factors and optimization was done by desirability index method. Findings indicated that composites having 30% Sesamum indicum L. irradiated at 125 kGy demonstrated best mechanical properties. A significant enhancement in tensile and flexural properties of irradiated composites can be explained effectively in terms of the cross-linking effect. The fiber–matrix adhesion and modifications in composite structure was characterized by fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X-Ray diffraction (XRD) analysis. Furthermore, thermal stability of the composites was also found to be increased. In addition, gamma-irradiated composite exhibited the highest storage modulus and a decrease in mechanical loss factor was also observed. [ABSTRACT FROM AUTHOR]

In this study, the thermos-mechanical characteristics of bamboo fiber-reinforced epoxy polymer composites made by compression molding and hand lay-up techniques are discussed. A lab-scale compression molding machine was fabricated for this purpose using the scrap materials of the Central workshop of Tezpur University, India. To find the suitable NaOH concentration for bamboo fiber strip treatment, bamboo strips were treated with 5, 8, 12, and 15 wt.% NaOH solutions for 12 h in each sample. It is determined that 12 wt.% NaOH treated bamboo strips were optimal for the fabrication of composites by single fiber tensile test, single fiber pull-out test, scanning electron microscopy (SEM), and Fourier transforms infrared spectroscopy (FTIR). Alkali treatment improved the interfacial strength with epoxy resin. It is seen that 8, 12, and 15 wt.% NaOH treated bamboo fiber strips become more compatible with the resin. The investigation explored the effects of mechanical and thermal characteristics of composites fabricated by the two different fabrication techniques. The thermal behavior of composites was investigated using thermogravimetric analysis (TGA). The Mechanical properties of composites produced by compression molding machine are found to be better than the hand lay-up method. [ABSTRACT FROM AUTHOR]

In this paper, hydrophilic cotton (CO) yarn and hydrophobic cross-section polyester (PET) filaments were used to prepare single-layer interwoven fabrics (CO/PET fabrics) with plain, 3/1 twill, and 8/5 satin to formulate a hydrophobicity–hydrophilicity gradient across the fabric for obtaining a good water transfer ability. The CO fabrics and PET fabrics were prepared for comparison. The contact angle and thermo-physiology properties of the fabrics, including the wicking property, moisture management ability, drying property, air permeability and water vapor permeability, thermal property, and dynamic cooling property, were investigated. The results show that the asymmetric hydrophobicity–hydrophilicity characteristic can be formed across CO/PET fabric with 3/1 twill and 8/5 satin. This can improve the water transfer ability from the inside to the outside of the fabrics, and the longer the floating length of the fabric is, the stronger the water transfer ability is. These two fabrics also exhibit excellent wicking properties, overall moisture management capability, and thermal comfort, and have good permeability, drying properties, and dynamic cooling properties compared to the corresponding fabrics. As a result, these two CO/PET interwoven textiles are more suitable for application as clothes worn in summer. The interweaving technique combining hydrophilic and hydrophobic yarns is an easy and cost-effective method to prepare fabrics that meet summer requirements. This work provides insight into the thermal and moisture comfort property of interwoven fabrics for summer garments. [ABSTRACT FROM AUTHOR]

Textiles are essential for providing thermal and wet comfort for people as well as aesthetic pleasure since they act as the interface between the human body and the environment. Maintaining thermal comfort is crucial for effective human body energy management in cold weather. It is essential to develop winter fabrics that effectively integrate hygroscopic heat generation and moisture management technologies to keep skin warm and dry for the wearer. In this study, we fabricated bilayer and trilayer woven fabrics with hygroscopic exothermic properties and moisture management performance based on the optimization design of gradient wettability and functional fiber materials. The air permeability, moisture management characteristics, thermal physiological properties, and hygroscopic heat generation performances of the developed fabric were investigated from the perspective of yarn composition and structure. These fabrics were demonstrated to achieve efficient water transport and durative and evenly distributed hygroscopic exothermic properties to avoid the cold moist feeling after sweat. We anticipate that the fabric strategy used in this work can provide valuable structural superiority and performance enhancement for smart thermal and wet comfort textiles. [ABSTRACT FROM AUTHOR]