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.

Cellulose stearates were prepared in a 1-butyl-3-metylimidazolium chloride ionic liquid. The addition of base pyridine as well as catalyst Tin octoate sufficiently increases the degree of hydroxyl group substitution. The new path for preparation of cellulose mixed esters, namely cellulose acetate stearate (CAS), is performed. The 1H NMR data confirmed the structure of obtained mono- and mix- cellulose esters.

Recently, a deliberate interest to look for composites that are eco-friendly and biodegradable appears. Therefore materials based on raw materials derived from natural resources of plant are being studied. One of the most promising bio-based polymers that have attracted the interest of many researchers is poly(lactic acid), which is made from plants and is readily biodegradable. Cellulose is one of the strongest and stiffest fibres available and it has a high potential to act as reinforcing agent in biopolymers. In our work we esterified cellulose using stearoyl chloride in ionic liquid and studied the effect of cellulose stearate addition to matrix polymers on thermal and rheological properties.