The rheological properties of coal bitumens modified by polyesters. Rapid Communication

Abstract

The purpose of testing was to find changes of rheological properties of coal-tar pitch (CTP) due to modification with chosen polyesters. Poly(ethylene terephthalate) (PET), unsaturated polyester resin (UP) and polycarbonate (PC) were selected for testing. Polymers, in the amounts of 10 and 25 wt %, were mixed with CTP under conditions considered optimal for each modifier type. Properties of CTP-polymer compositions were assessed based on their softening point, content of components insoluble in toluene and quinoline and on rheological properties. Distinct changes of rheological properties, especially changes in viscosity versus shear rate and temperature, as well as viscoelastic properties were observed as results of modifications with all used polyesters. The modification effects became more intensive with increasing amount of the modifier added to CTP.

Thermo-rheological properties of coal-tar pitch modified with phenol-formaldehyde resin

“…coals subjected to high-temperature carbonizing process in order to obtain porous materials, it is essential to assure high flowability (low viscosity) at carbonizing conditions as well as appropriate mechanical strength. Addition of polymers to such materials as a rule results in the increase in viscosity and thereby in worsening the flowability [8,10]. Due to very low viscosity of coal-tar pitch, addition of polymers can-despite the effect of viscosity increase-play an advantageous role, increasing its thermal and mechanical resistance at the same time.…”

“…Use of polyesters [8][9][10] as modifying agents can be an example. Modification of coal-tar pitch with unsaturated polyester resins leads to considerable plasticization, and such modified bitumens of significantly lower cancerogenicity can be used as binders with insulating and sealing properties.…”

Waste poly(methylene methacrylate) as precursor for activated carbons

“…At the Institute of Chemistry, Warsaw University of Technology in Plock, we have been carrying out studies on bitumen-polymeric materials for several years now. They are aimed at the improvement of utility properties of coal-originated bitumen and utilization of waste polymers [13]. Makomaski et al [14][15][16] have proved that polymer-pitch compositions can be used for the preparation of activated carbons.…”