Materials, Methods & Technologies, Volume 16, 2022

Rezumat: For polymeric materials, the resistance to elevated or reduced temperatures is important. The thermal stability of a polymer determines its functional usability, and it is defined as a range of temperature, in which the polymer retains its elastic properties. The thermogravimetry was used for determination of thermal stability of biopolymers filled polymer composites. For observation of structural changes after the addition bio-fillers to polymer composites, the infrared spectroscopy was used. The most common biopolymers with interesting properties, which have been used as filler, are the cellulose, chitosan, galactomannan, starch and soy protein isolate. Natural rubber (NR) was blended with galactomannan (LBG), cellulose (CEL), chitosan (CHS) or soy protein isolate (SPI) as a filler in amount 0, 30 and 55 phr. The results indicate that the thermal degradation of NR/CEL, NR/CHS, NR/SPI and NR/LBG polymer composite in nitrogen is a three–step process. The first step is assigned the destruction of biopolymers. The second step is assigned to the decomposition of double bonds of methylene groups in polyisoprene molecules, i.e., to the decomposition of natural rubber. The third step is the carbonization of natural rubber.