Influence of cellulose content on thermal properties of poly(lactic) acid/cellulose and low-density polyethylene/cellulose composites

Abstract

Crystallization behaviour of polylactic acid/cellulose (PLA/CELL) and linear low-density polyethylene/cellulose (LDPE/CELL) composites was studied by differential scanning calorimetry (DSC) and polarized light microscopy equipped with hot-stage. The effect of addition of cellulose on thermal properties of PLA/CELL and LDPE/CELL composites was considered. The DSC experiments were performed at different scanning rates.For pure PLA the crystallization peak at r= 98.8 °C was observed in DSC scans at 20°C/min with the corresponding melting peak at 110.1°C. With addition of cellulose no crystallization peaks and melting peaks related to them were found. For all samples cold ciystallization peaks at around 130°C and corresponding melting peaks at 152-153 °C were observed in endotherms. Cold crystallinity is strongly affected by cellulose content: the higher the cellulose content, the higher is the cold crystallinity of the samples. At the same time overall crystallinity for all PLA/cellulose composites is negligible contrary to pure PLA, which is slightly crystalline.Unlike PLA, LDPE and its composites have no cold crystallization, which is a usual behaviour for LDPE materials. A general crystallization/melting behaviour of LDPE/cellulose composites is identical to that of pure LDPE. However, the crystallinity of LDPE/composites decreases with increasing cellulose content.

Thermal properties and degradability of low density polyethylene microcrystalline cellulose composites

“…The results reveal a sharp reduction in the percentage crystallinity from about 58% for pure LDPE to about 11% at a MCC concentration of 30 wt% within the matrix. This reduction in the percentage crystallinity agrees with what Šumigin et al 23 and Sdrobis et al 21 reported in their work.…”

“…This outcome contradicts with what was stated by Tajeddin et al 1 and Sdrobis et al, 21 where the authors confirmed that melting temperatures of LDPE/cellulose composites increase as the concentration of cellulose increases. Pasquini et al, 22 Šumigin et al, 23 and Pöllänen et al 24 stated in their publications that the crystallization and melting temperatures for pure LDPE will be almost as same as with LDPE adopted by cellulose.…”

The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

“…the -F groups of the polymer chain). So, the degree of crystallinity of the blend matrix increases with the addition of HPC [29]. As can observe, the T g and T m are affected by the HPC content in the blend showing that the polymers are miscible.…”

Matrices from vegetable oils, cashew nut shell liquid, and other relevant systems for biocomposite applications

“…203 Of particular interest are PLA composites reinforced with cellulose. 204 It has been demonstrated that the cellulose particles behave as nucleating agents, and therefore increase the cold crystallinity of the final composite. 204 As demonstrated in previous studies, the modification of cellulose is crucial in order to obtain significant improvements in mechanical properties.…”