Preparation and stabilization of saccharide fiber produced by centrifugal spinning

Abstract

The objectives of this study were to prepare saccharide fiber via centrifugal spinning and further investigate its stability under stress condition. Different saccharides were chosen and spun via centrifugal force to form thread like matter. The results indicated that sucrose (SC) and trehalose (TH) could be fabricated as fiber whereas other saccharides were not able to form. The formation of fiber mainly involved with glass transition temperature (Tg), molten ability including stability of saccharide after melting. High Tg saccharides were a good candidate on fiber preparation. Homogeneous melting with appreciable stability was another factor affecting on fiber preparation. Decomposing after melting of some saccharides was prone to unsuccessful fiber formation. Three main factors regarding to the stability of fiber produced were Tg, amorphous content and defect on the surface. Tg of both SC and TH fiber were found to be 58.13 and 60.10 °C that were higher than room temperature. They should be thus stable due to high Tg or glassy state. However, their fiber structure collapsed within hour time of scale. It was due to amorphous nature with surface defect. SC fiber was amorphous with rougher surface compared to TH fiber. Thus, TH fiber was more stable than SC fiber. In order to improve the stability of fiber, blending of different saccharides was proposed due to the ability for changing Tg. In this study, SC was selected as the main saccharide. TH was then incorporated before fiber fabricating. Monitoring of the Tg of mixture (Tg (mix)) showed the non-linear relationship between Tg (mix) and the amount of TH added. Low weight fraction of TH showed plasticization while higher weight fraction (>0.5) TH provided antiplasticization. All Tg (mix) observed were lower or close to ambient temperature that impacted on the collapsible of fiber structure. In addition, they existed as amorphous with smoother surface. Therefore, Tg and amorphous were the significance factors on the stability of fiber produced from the mixture of SC&TH. Nevertheless, not only the scanning of fiber morphology with scanning microscope but the smoothness of surface was also assessed with moisture sorption profile. The result showed that the SC&TH fiber took longer time of moisture sorption or known as “transition time” including longer recrystallization time when increasing the weight ratio of TH. It could be concluded that longer of transition and recrystallization time meant to the smoother surface or less defect of fiber. Therefore, TH could improve the stability of SC fiber via the formation of less surface defect fiber more than the adjustment of Tg or the increasing of crystallinity. In conclusion, SC fiber was more stable by the incorporation of TH. However, the physical stability of TH spinning fiber sound to be better compared to SC&TH fibers. Thus, TH should be selected as saccharide base for centrifugal spinning fiber. The further study of the effect of crystallization enhancer or modifier on TH fiber formation was recommended.