Structure and Properties of Fluoroplastic and Ultrahigh Molecular Weight Polyethylene Produced by Shock-Wave Pressing

Study of the Effect of Shock-wave Treatment on the Structure and Properties of Phenylone

“…From Figure 4 it can be seen that both materials acquire maximum hardness after heat treatment at a temperature of 360°C, the microhardness being higher for Phenylone produced by explosive treatment than for statically pressed Phenylone. Furthermore, in spite of the identical hardness of specimens in the region of the glass transition temperature, for material after explosive treatment the hardness increases more intensively, which confirms the better intermolecular interaction in the polymer, with possible crosslink formation, as in polymers previously investigated (UHMWPE, F-2M) [4]. As a result of this, the strength and deformation characteristics of the polymer change.…”

“…Owing to the increased rigidity of its macromolecule chains and strong intermolecular interaction, this polymer is characterised by low deformability in the region of the softening point and flow temperature, which makes it a difficult material to process by normal methods [1]. A promising method for processing Phenylone is explosive pressing (EP), enabling practically any pressures to be realised and not requiring high-power press equipment [2,4,5].…”

“…Table 2 gives the physicomechanical properties of Phenylone S3 produced by explosive pressing in Figure 6. TMA curves of Phenylone S3 obtained by static (1,3) and explosive (2,4) pressing before sintering (1,2) and after sintering at 360°C (3,4) comparison with the properties of Phenylone S2 produced by hot pressing [1]. From an analysis of the results of testing their properties it can be seen that Phenylone S3 produced by high-speed pressing hardly differs from Phenylone S2 produced by the more labour-intensive and time-consuming method, but in strength and hardness it is superior.…”

Thermomechanical Properties of Fluoroplastic–Copper Composites

“…As follows from the experimentally obtained dependences (Figure 4), the maximum thermal expansion (at 415°C) of pressings of composites with 10% metal fi ller after SWC (without sintering) is almost twice as low (ε′ 415 = 39%) as after SC (ε′ 415 = 74%), which is due to the increased adhesion interaction realised during shock-wave treatment [7][8][9]. Reduction in thermal expansion, connected with the formation of a strengthening interphase layer through an increase in interaction of the matrix and fi ller, is intensifi ed by self-reinforcement of the polymer, and also by possible reduction in the degree of crystallinity of PTFE after SWC [8,9]. With increase in the copper concentration in the composite from 10 to 30% there is a reduction in the maximum possible strains of thermal expansion at 415°C from 74 to 36% after SC and from 39 to 28% after SWC.…”

“…The use of shock-wave energy for the treatment of powder mixtures of polymers with fi ller is a promising direction for the development of methods for producing polymer composites by high-energy action ensuring simultaneously the compaction, forming, thermodynamic activation, and consolidation of powders of adhesioninert difficult-to-process polymers and their filled composites [7][8][9].…”