Swelling Parameters and Mechanical Properties of Functional Fibers Based on Butyl Methacrylate-Hydroxyethyl Methacrylate Copolymer

Butyl methacrylate-hydroxyethyl methacrylate (BMA-HEMA) copolymers were synthesized by the method of suspension polymerization. The copolymer fibers were prepared for absorbing liquid organic matter by gelation-spinning in a twin screw extrusion machine. The swelling parameters and mechanical properties were investigated, and the morphology was observed by scanning electron microscope (SEM). The results show that the degree of equilibrium swelling for the fibers increased with increasing the mass fraction of HEMA in the monomer feed when toluene, trichloroethylene, or chloroform were selected as organic absorbates. All of the interaction parameters, χ ₁, for the fibers and organic liquids were less than 0.5, with the order of the interaction parameters χ ₁ being as follows: toluene > trichloroethylene > chloroform. Average molecular weights between crosslink points, M _c, and effective crosslink density, V _e, were dependent on the selected organic liquids; for the different organic liquids, M _c and V _e were different. The breaking tenacity, initial modulus, and yield stress of the fibers increased with an increase in the mass fraction of HEMA. However, elongation at break and elongation at yield decreased with increasing the mass fraction of HEMA; in particular, for the mass fraction of HEMA equal to 15 wt%, the fiber did not yield, and underwent a brittle fracture.