Development of biomass carrier from high-filled with microcellulose LDPE

In this paper, a composite material based on LDPE filled with 30 vol.% wood microcellulose (MC), in order to assess the possibility of its use as a biomass carrier treatment facilities.The material was obtained in industrial conditions by means of a twin-screw extruder with a leaf head, then samples of a composite biomass carrier in the form of discs with a diameter of 4 cm and a thickness of 1.5 mm were obtained from the sheet by means of a cutting press.Investigated the microstructure and morphological parameters of the composite, it was found that the porosity is about 58%, the surface roughness is 3.5 units of density about 450 kg/cubic m. the basic technological parameters of the melt of the composite by the method of capillary viscometry, the dependences of the shear stress and the melt viscosity of the test material in the velocity range processing, it was found that the composite refers to satisfactory recyclable thermoplastics. Bagley correction was performed. The thermomechanical stability of the material was investigated, the critical temperature of processing-200 °C. the operational properties of the material were Investigated: the tensile strength was 1.6 MPa, the elongation at break-12%, water absorption for 24 hours of soaking-31.2%. The dry biomass residue of activated sludge for 10 days of its immobilization on a composite biomass carrier amounted to 5.54%, which exceeds by 2.4 times the biomass growth on the traditionally used material-pure polyethylene. The material has a relative chemical resistance, does not lose its performance over a long period of operation. In particular, the loss of tensile strength after 5-fold freezing, soaking in 0.01 n solutions of sulfuric acid, acetic acid and sodium hydroxide (for 6 months), exposure to UV solar radiation (for 12 months), soaking in water (for 12 months) did not exceed 10-12%. Thus, the composite composition of LDPE: MC (70: 30 vol.% ) can be recommended for use in biological treatment plants as a highly efficient carrier material-biomass.

Rheological behavior of binary polymer compositions

The article presents the results of a study of the rheological behavior of binary composites based on serial polyethylene grade LDPE 15803-020 with different content of microcellulose grade Filtracell, in a wide range of temperatures and shear rates during deformation through a capillary diameter of 1 mm and a length of 5 and 30 mm. Stable flow regime is manifested in the temperature range from 160 to 200°C for composites containing microcellulose in an amount of 30 wt.%, and its partial replacement with spent microcellulose (waste production of vegetable oils) can reduce the effective viscosity to 25%, but the upper limit of the temperature range is limited to the exudation of impurities (190°C). The Bagley correction is carried out, the coefficients of the equations describing the dependences of the true shear stress, regardless of the capillary length, are calculated.

Analysis of Entrance Converging Flow of Polymer Melts. A Comparison between Liang Model and Cogswell Model

In this paper, a comparison between the Liang model and the Cogswell model is made by using them to simulate numerically the boundary streamline and the region length during the entrance converging flow of polymer melts. The results show that both of them can properly describe the flow conditions. Furthermore, the Liang model can accurately describe the geometry effect on the boundary streamline, and by introducing the Bagley correction factor e and the slip factor ξ, it can also describe the changes of the region length more precisely.

Evaluation of Different Methods for Determining the Entrance Pressure Drop in Capillary Rheometry

Two approaches for determining the entrance pressure drop in capillary rheometry were compared with low-density polyethylene and polystyrene melts as test fluids. Direct measurements with the orifice die were found to yield higher values for the entrance pressure drop, and hence lower values for the wall shear stress, than the Bagley correction method. This was postulated to be caused by the sticking of the melt to the wall of the outlet region of the orifice die. The additional pressure drop created in the outlet region of the orifice die, when the flowing material fills it completely, was also evaluated by means of numerical flow simulation.