Modification of cellulosic filler with diisocyanates - volatile organic compounds emission assessment and stability of chemical structure over time

This paper investigated the impact of type and content of diisocyanate on the structure of modified cellulose fillers. Four the most popular isocyanates were applied - isophorone, hexamethylene, toluene and methylene diphenyl diisocyanate - at loadings of 1-15 wt%. Chemical structure, and its short-term storage stability, were investigated for eight weeks. Moreover, the main volatile organic compounds detected during modification, as well as emitted from fillers before and after storage, were identified. The main compounds detected in the air during modifications were terpenes and terpenoids. No diisocyanates were detected, which is very beneficial considering their toxicity. They were emitted from modified fillers at 40 degrees C, but only from fresh samples. After storage no emissions were noted, which indicated successful modification of fillers, also confirmed by FTIR spectroscopy and changes in polarity of fillers' surface. Observed changes should be considered beneficial for the potential applications of modified fillers in manufacturing of polymer composites.