Synthesis of Sustainable and Stable Latex of Biopolymer Encapsulated Nanolignin-Clay Hybrid Via Miniemulsion Polymerization

Synthesis of sustainable and stable latex of biopolymer encapsulated nanolignin-clay hybrid via miniemulsion polymerization

Suguna Jairam, Zhaohui Tong*

Agricultural and Biological Engineering Department, IFAS, University of Florida,

Gainesville, FL, 32611-0570

Email: ztong@ufl.edu

Everyday usage of water-borne dispersions (latex) cannot be understated, with wide areas of application ranging from usage in packaging, medicine, to food and structure. Stable and sustainable latex from renewable resources will attract a lot interest due to its advantages of better environmental concern, easy manipulation and energy saving. In addition, the lack in enhanced functionality of these latexes demands an improvement of their properties such as anti-microbial properties, barrier to heat, gas and moisture, UV-protection and mechanical properties. Therefore, this project aims to synthesize a novel water-borne dispersion encapsulating nano-lignin/clay hybrid in a bio-based acrylated polymer derived from bio-based glycerol and/or free fatty acids from waste stream of biodiesel. Preliminary studies were performed on the synthesis of nanolignin-clay hybrid and the encapsulation of this hybrid into polymer to form stable latex.  The lignin extracted from bioethanol process was modified to quaternary ammonium lignin and it can be loaded on the clay surface to produce an organophilic hybrid. FTIR analysis of clay before and after lignin addition showed successful binding and thermogravimetric analysis of the hybrid showed about 32% (by weight) loading of lignin on clay.  Furthermore, miniemulsion polymerization was applied for the encapsulation of organophilic hybrid into both petroleum- and bio-based polymer and stable latex was formed. X-ray diffraction demonstrated the intercalation of nanohybrid in the polymer matrix. The property results showed that the encapsulation of nanolignin-clay hybrid improved tensile strength and thermal stability of final latex film.