Samples were ground in liquid nitrogen using a
IKA A11 basic Analytical mill (IKA Works Inc., NC, U.S.) for 10 s.
Test specimens included PP þ 2% additive, co-polyester þ cornbased
plastic, wheat starch-derived plastic, paper pulp, paper
pulp þ asphalt, coconut coir and rice hull (Tables 2 and 3). Samples
were incubated in triplicate for 660 days.