Comparative Biodegradation Studies of Butyl and Dodecyl - Functionalized Carbon Nanofibers Dispersed in Cellulose Acetate Polymer Nanocomposites

Biodegradable nanocomposites incorporating carbon nanofibers (CNFs) have gained significant traction due to their environmentally friendly nature. The use of functionalized CNFs enhances the mechanical, thermal, and electrical properties of nanocomposites. The ultimate properties and biodegradation rate of these nanocomposites are significantly influenced by the type and structure of the CNFs dispersed within the biodegradable polymer matrix. Nanocomposites were prepared by blending 0.2% w/w of the functionalized butyl, and dodecyl CNFs in cellulose acetate polymer matrix. The study sought to establish the effect of the butyl, and dodecyl moieties on the degradation rate of biodegradable cellulose acetate. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to determine the dispersion of CNFs within the polymer matrix and the surface characteristics of the resulting nanocomposites. Respirometry (CO<sub>2</sub> emission) and gravimetry (change in mass) techniques were used to determine the biodegradation rate of the nanocomposites. The study found out that incorporation of functionalized CNFs into the biodegradable polymer matrix had an impact on the biodegradation rates of the formed nanocomposites. From the cumulative amounts of CO<sub>2</sub> evolved during the respirometry and cumulative weight lost during the test period, the nanocomposites had a reduced rate of degradation compared to the reference blank. This could be attributed to an increase in polymer crystallinity caused by the addition of the alky moieties that increased the adherence of the CNFs to the polymer matrix. Individual alky functionalized nanocomposite also had different rates of degradation with the butyl nanocomposite degrading much faster than the dodecyl, respectively. Overall, the results indicated a slight increase in the time required for the nanocomposite to degrade to less than 1% of the original sample as compared to the reference blank. The study and its findings have generated new scientific knowledge that could be relevant in the fabrication biodegradable nanocomposites based on a diverse range of other polymeric and nonpolymeric matrices and importantly approximately how long the fibers can be in the environment after their useful life.