− A series of polyethylenes was obtained by modification of two commercial high-density polyethylenes. The organic peroxide concentrations and irradiation dosis used are below the critical ones that produce molecular networks. The molecular weights of the polymers increase, and the molecular weight distribution gets wider, as the concentration/dose increases. These results are a consequence of ...

The paper presents partial results of an ongoing project dealing with thermal diffusion and mechanical behavior of spruce wood in high temperature environment (up to 180°C). The objective of this part of study was to obtain rheological properties of spruce wood which will be used in future modeling of wood performance in high temperatures. Oven dry samples (30 x 30 x 700 mm) underwent constant ...

Twin screw extrusion based pretreatment of biomass is an attractive option due to its flexibility to carry out chemical reactions under relatively high stresses, temperatures and pressures. However, extrusion processes are rarely utilized in biomass pretreatment because such processing is constrained by rheological behavior of typical biomass suspensions. Without the manipulation of their rheol...