Description:
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:justify;text-justify:inter-ideograph;line-height:normal"><span lang="EN-GB" style="font-size:9.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";mso-fareast-language:EN-GB">Shapememory polymer based thermal and moisture responsive fabrics are becoming avery promising solution for personal thermal comfort with self-adaptivefunction to respond to real-time changes of body micro-climate and external environment.Both in filament of fabric coating forms, thermal and moisture responsivefunction is achieved at both microscopic and macroscopic scales by adjusting molecularchains mobility, hence porosity of the structure. Besides common structuresresponsive to one stimulus; temperature and humidity, multimode shape memorytextiles responsive to more than stimulus simultaneously have been neededrecently in generally nanocomposite form including different stimuli-responsivecomponents. Herein, dual-responsive cellulosic knitted fabrics (cotton, viscose,modal, lyocell, bamboo) having dynamic breathability function were developedwith temperature-moisture responsive nanocomposite finishing treatment by apad-dry-cure process. Having its intrinsic temperature response function, shapememory polyurethane (SMPU) was reinforced with cellulose nanowhiskers (CNW) tocreate percolation network for additional moisture responsive function. Dynamicbreathability function was tested with water vapour permeability (WVP) testsunder different temperature (20°C-40°C) and relative humidity (40%, 60%) environments.According to the results, treated cellulosic fabrics, especially modalexhibited adaptive WVP. The mentioned temperature-responsive function can beattributed to the free volume increasing soft segment, micro-Brownian motionopening transfer channels 40°C above<i> T<sub>g</sub></i>=32°Cof SMPU polymer and additional micropores and free volume created by CNWs withinSMPU matrix. Disrupting hydrogen bonds among CNWs by water molecules whichincreases porosity at higher moisture levels is the reason of moisture-responsivefunction. Optimization of fabric hand, which was one of the aims, is crucialfor such kind of cellulosic fabrics that 1.31x bending rigidity increment wasachieved for modal. SEM and FT-IR analysis results confirmed coating andfabric-nanocomposite interactions in turn. Summing up, modal fabric can besuggested for a next-to-skin clothing having dynamic breathability keeping itssuperior hand.<o:p></o:p></span></p>