Effects of Glycerol on Melt Spinning of Polyacrylonitrile Copolymer and Tetrapolymer

• Published in: Fibers and polymers 2020, 21(2), , pp.376-383
• Main Authors: Im, Yeong Min, Choi, Hye Mi, Nathanael, A. Joseph, Jeong, Min Hye, Lee, Seung O., Yun, Sung No, Oh, Tae Hwan
• Format: Article
• Language: English
• Subjects: Acrylic acid; Acrylics; Carbon fiber reinforced plastics; Carbon fibers; Chemical industry; Chemistry; Chemistry and Materials Science; Copolymers; Draw ratio; Drawability; Extrusion; Filaments; Glycerol; Melt spinning; Polyacrylonitrile; Polymer Sciences; Polymers; Shear rate; Tensile strength; Viscosity; 섬유공학
• ISSN: 1229-9197; 1875-0052
• DOI: 10.1007/s12221-020-9412-z

Comonomers vinylimidazole, methyl acrylate, and acrylic acid were added to acrylonitrile to synthesize two polymers, poly(acrylonitrile-co-1-vinylimidazole) and poly(acrylonitrile-co-N-vinylimidazole-co-methyl acrylate-co-acrylic acid), with the goal of enhancing their melt processability for their use as carbon fibers. The two polymers were melt-extruded, but the as-spun filaments were brittle. Therefore, glycerol was mixed with the polymers to improve their spinnability and drawability. The addition of glycerol to the polyacrylonitrile copolymer and tetrapolymer reduced their melt viscosity, enhanced their melt spinnability, and improved their drawability. When 15 % (w/w) glycerol was added, the melt viscosity of the two polymers was reduced to below 1000 Pa·s at a shear rate of 100 s -1 , and the tensile strength of the resulting filaments was high enough for them to be used as precursor filaments for carbon fibers. Furthermore, a draw ratio of over 5.5 was achieved for the melt spun filaments of mixtures of the copolymer and tetrapolymer with 15 % glycerol (w/w) at a temperature of 150 °C.