Preparation and Characterization of Calcium Carbonate Masterbatch-Alkali Soluble Polyester/Polyester Porous Fiber via Melt Spinning

Porous fibers have gained significant attention for their lightweight and high porosity properties in applications such as insulation and filtration. However, the challenge remains in the development of cost-effective, high-performance, and industrially viable porous fibers. In this paper, porous fibers were fabricated through the melt spinning of an alkali soluble polyester (COPET)- CaCO3 masterbatch and PET slice. Controlled alkali and acid post-treatment techniques were employed to create porous structures within the fibers. The effects on the morphology, mechanical, thermodynamic, crystallinity, pore size, and thermal stability were investigated. The results indicate that the uniform dispersion of CaCO3 particles within the fiber matrix acts as nucleating agents during the granulation process, improving the thermal resistance and strength of the porous fiber. In addition, the porous fiber prepared by COPET/CaCO3 to PET with an 85/15 ratio and post-treated on 4% NaOH and 3% HCl exhibits a "spongy body" with uniformly small pores, favorable strength (2.71 cN/dtex), and elongation at break (47%).