Structure and Properties of Alkaline Lignin-filled Poly(butylene succinate) Plastics

Poly(butylene succinate) (PBS), with similar physical properties to those ofpolyethylene, is degradable and can be used as a common material. However,it is not adopted widely in industry and domestic applications due to its high cost.In this work, to improve the performances and wide applicability of PBS, a newbiodegradable blend has been prepared by incorporating alkaline lignin (AL) filler intoPBS as a matrix. First, the AL and PBS, where the weight percentage of the former inthe blends varied between 5 and 30%, were mixed at a rotating speed of 78 rpm for10 min at 120°C; and then, the resultant mixture was compression-moulded into asheet at 120°C under 20 MPa pressure for 5 min. Moreover, methylenediphenyldiisocyanate (MDI) was used as coupling agent to further modify new PBS/AL blends,and the weight percentage of MDI was regulated from 0.5 to 2%. The structure andproperties of the resultant blends were investigated by Fourier transform infraredspectroscopy, X-ray diffraction, differential scanning calorimetry, scanning electronmicroscopy, swelling, tensile and water absorption tests. The results showed that theaddition of AL inhibited the crystallization of PBS matrix, and enhanced the Youngsmodulus of the blends. In addition, it was found that the addition of MDI favouredfurther enhancements in tensile strength and Young's modulus, and reduced the waterabsorption of the blends.