Fundamental Structural and Kinetic Principals of High Strength UHMWPE Fibers Production by Gel-Technology

One of the main research work in the field of polymeric materials was, is and always will be the improvement of their mechanical properties. Comprehensive structural studies of UHMWPE reactor powder, the features of its dissolution and the formation of a gel-state, as well as UHMWPE films oriented up to various draw ratios, were carried out using scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. For comparison, decalin and vaseline oil were chosen as solvents. The mechanical properties of oriented UHMWPE films were also studied. In the process of orientation drawing, basing on the developed structural-kinetic principles of strengthening for highly oriented speciments gel-cast from UHMWPE powders, the average values of tensile strength of 4.7 GPa (about 6% of the samples had strength values up to 6.0 GPa) and an Young's modulus of 170 GPa (about 6% of the samples had Young's modulus values of 200 GPa). These values are among the highest according to the world scientific literature. A significant increase in the mechanical characteristics of highly oriented UHMWPE films was achieved using experimentally confirmed scientific approaches to revealing the structure-property relationship at each stage of the gel process.