Biofibres from biofuel industrial byproduct-Pongamia pinnata seed hull

Incorporation of canola meal as a sustainable natural filler in PLA foams

The canola oil industry generates significant waste as canola meal (CM) which has limited scope and applications. This study demonstrates the possibility of valorization of CM as a sustainable natural filler in a biodegradable polymer composite of Poly(lactic acid) (PLA). Generally, interfacial bonding between natural fibers and the polymer matrix in the composite is weak and non-uniform. One possible solution is to derivatize natural fibre to introduce interfacial bond strength and compatibility with the PLA polymer matrix. Here, CM was succinylated in a reactive extrusion process using succinic anhydride at 30 wt% to get 14% derivatization with 0.02 g of -COOH density per g of CM. The CM or succinylated CM at 5 and 15 wt% was co-extruded with amorphous PLA to get composite fibers. CM-PLA and succinylated CM-PLA biocomposites were foamed using a mild and green microcellular foaming process, with CO2 as an impregnating agent without any addition of organic solvents. The properties of the foams were analyzed using differential scanning calorimetry (DSC), Dynamic mechanical thermal analysis (DMTA), shrinkage, and imaging. The addition of CM or succinylated CM as a natural filler did not significantly change the glass transition temperature, melting point, percent crystallization, stiffness, and thermal stability of PLA foams. This suggests succinylation (modification) of CM is not a mandatory step for improving interphase compatibility with the amorphous PLA. The new PLA-CM foams can be a good alternative in the packaging industry replacing the existing petroleum-based polymer foams.

Millettia pinnata: a study on the extraction of fibers and reinforced composites

In this work, the potential for using Millettia pinnata stalk for extracting cellulosic natural fibers and its subsequent use in reinforced composites was studied. The extracted fibers were characterized for its composition, mechanical, thermal stability and morphological properties. Compositional analysis showed that the fibers possessed 54% cellulose, 12% hemicellulose, 15% lignin and 11% ash. The tensile strength of the fiber was 310 MPa, which is comparable to cotton and linen. The tensile strength of the M. pinnata fiber-reinforced polypropylene composites was 17.96 MPa which was similar to other natural fiber-based composites. M. pinnata fibers appear promising for a wide range of applications including textiles and other typical composites applications.