Potentialities of cellulose nanofibers (CNFs) in low density polyethylene (LDPE) composites

The growing demand for polymeric materials has made them signifcant in both industry and the environment, and the task of making them sustainable is becoming increasingly challenging. Cellulose presents an opportunity to minimize the efect of nondegradable materials. Cellulose nanofbers (CNFs) are a class of cellulose fbers with superior performance due to their high strength and stifness combined with low weight and biodegradability. This work aimed to produce composites using low-density polyethylene (LDPE) as a matrix and CNFs from Pinus sp. (Pinus) and Eucalyptus sp. (Eucalyptus) as reinforcements. The CNFs were obtained by mechanical defbrillation of the cellulose, and subsequently, the water was removed by centrifugation to produce a master with CNFs and LDPE using a thermokinetic homogenizer. The master was milled and blended with LDPE to obtain booster concentrations of 1, 2 and 3% by weight (wt%). To characterize the composites, tensile and fexural tests and thermal and rheological analyses were performed. An increase of between 3 and 4% in the crystallinity of the composite was observed with the addition of Pinus CNF, and a decrease of 2 to 3% in the crystallinity index was observed with the addition of Eucalyptus CNF. The thermal stability increased for all the compositions. For the mechanical properties, increasing the CNF content increased the stifness and tensile strength. In general, this process is an efective alternative for producing composites of LDPE with cellulose nanofbers