Fabrication of All-Cellulose Composite from Cotton Fabric via NaOH/Urea Solvent Using Vacuum Bagging-Assisted Process

Abstract

All-cellulose composites (ACCs) become growingly attractive materials in wide range applications due to its green profile, biocompatibility, and enable recycling. In this work, the ACCs was fabricated from cotton fabric (CF) by partial dissolution via aqueous NaOH/urea solution. The alternative ACC fabrication technique using vacuum bagging in the dissolution step was introduced in this study. SEM images confirmed that a vacuum aid during CF-ACC fabrication effectively improved the consolidation of resulting composites, showing better bonding and structure integrity. The CF-ACC prepared with vacuum bagging-assisted process showed almost two-fold enhancement in tensile strength as compared to another one prepared without vacuum bagging. The effect of dissolution time (15-45 min) on structure and properties of CF-ACCs was also investigated. The CF-ACC prepared with vacuum bagging at dissolution time of 15 min showed the highest tensile strength of 35.25 ± 1.39 MPa and elongation of 21.17 ± 1.46 %. The longer dissolution time, the larger portion of the crystalline fibers dissolved and converted into the amorphous matrix phase of CF-ACCs (confirmed by XRD). With longer dissolution times, the tensile strength of the prepared composites was decreased. However, it was found that with increasing dissolution time and using vacuum bagging in the fabrication of CF-ACCs could enhance their Young’s modulus values, indicating a greater interfacial adhesion gained in these composite structures.

Low-Density All-Cellulose Composites Made from Cotton Textile Waste with Promising Thermal Insulation and Acoustic Absorption Properties

“…14,20−22 Due to their superior mechanical properties, renewability, and environmental benefits, ACCs have shown great potential in a wide range of applications, such as packaging, hydrogels, biomedical devices, photovoltaic devices, electro-active paper, and building materials. 13,22 Cellulose-based materials are considered an intriguing environmentally friendly choice for thermal insulation in buildings with an average thermal conductivity of about 0.040 W/mK. This value aligns with the thermal performance of conventional glass wool and rock wool insulations.…”

“…Consequently, a mixed solution of NaOH and urea has gained recent attention as a low cost and effective environmentally friendly solvent system for cellulose dissolution for the fabrication of ACCs. − Previous studies have demonstrated the successful production of ACCs from a wide range of cellulose textile sources, including cotton, rayon, linen, and flax. The ACCs with a density range of 0.9–1.3 g/cm 3 exhibited high modulus (0.9–28 GPa) and tensile strengths (46–460 MPa), respectively. ,− Due to their superior mechanical properties, renewability, and environmental benefits, ACCs have shown great potential in a wide range of applications, such as packaging, hydrogels, biomedical devices, photovoltaic devices, electro-active paper, and building materials. , …”

“…Cotton, covering 23% of the global fiber production share, is among the most commonly used textile fibers in the world. , Considering the significant amount of cotton waste generated by the textile sectors, many studies have focused on upcycling or recycling cotton textile waste (CTW). − Since cotton consists of more than 90% of cellulose, the utilization of cotton waste to develop all-cellulose composites (ACCs), in which cellulose serves as both the matrix and the reinforcing phases, presents a highly promising contemporary method for creating high-quality eco-friendly materials . There are two main approaches to develop ACCs: (1) partial dissolution (one-step processing), in which the cellulose fibers’ outer surface is partially dissolved to form a matrix phase that binds the remaining core fibers and (2) impregnation (two-step processing), where the reinforcing fibers are impregnated in a dissolved cellulose solution .…”