Characterization of Poly (Methyl Acrylate) Grafted Bleached Sulfite Pulp Fibers using AFM, AEM, EDS and STEM

Abstract

Sulfite pulp fibers were grafted by poly (methyl acrylate) at a low‐consistency (1% pulp consistency) and medium‐consistency (10% pulp consistency). It is of fundamental interest to determine the distribution of the polymer chains obtained at different fiber concentrations during grafting. In this study, modern analytical tools such as atomic force microscope (AFM), energy dispersive spectrometer (EDS), and scanning transmission electron microscope (STEM) were used for investigating the distribution of the polymer chains in the fiber matrix. AFM images in tapping mode showed that the fiber surface was covered with in‐situ generated polymers. The X‐ray mapping of Na in the cross‐section of the hydrolyzed grafted fibers by using EDS in combination with Na line scans by STEM showed that the distribution of poly (methyl acrylate) was affected by the pulp consistency during grafting; at a medium‐consistency condition the outer region of the fiber structure had a higher polymer concentration than the inner region. On the other hand, at a low‐consistency condition, grafting occurred uniformly across the fiber wall structure.

Keywords:

• AEM
• AFM
• cellulose fibers
• distribution of grafted polymer
• EDS
• grafting polymerization
• PMA
• pulp consistency
• STEM