Linking synthesis with entanglement state in Ultra High Molecular Weight Polyethylene; a route for solvent free processing*

In this presentation we will demonstrate differences in the density of the entangled state that could be realised on synthesising Ultra High Molecular Weight Polyethylene (UHMWPE); having number average molar mass greater than a million g/mol. The differences in the entangled state, having more than 10⁵ repeat units, have implications on processing in the solid state (below the equilibrium melting point) and chain diffusion of chain segments from non-crystalline to crystalline region. The polymers having reduced number of entanglements could be processed, free of solvent, into uniaxial and biaxial products leading to unprecedented mechanical properties required for the manufacturing of light weight recyclable composites. On melting the low entangled crystals of UHMWPE, a non-equilibrium melt state could be realised. The time required for the melt to transform from non-equilibrium to equilibrium state is shown to be dependent on the molar mass.
References: 1. Rastogi, S.; Lippits, DR.; Peters, GWM.; Graf, R.; Yefeng, Y.; Spiess, HW.; Nature Materials 2005, 4, 635-641 2. Rastogi, S.; Yao, Y.; Ronca, S.; Bos, J.; van der Eeem, J. Macromolecules 2011, 44, 5558-556; 3. Yao, Y.F.; Rastogi, S.; Xue, H.J.; Chen, Q.; Graf, R.; Verhoef, R. Polymer 2013, 54 (1), 411-422; 4. Andablo-Reyes EA; Auhl D; De Boer EL; Romano D; Rastogi S; Journal of Rheology 2017, 61 (3), 503-513; 5. Romano D; Tops N; Bos J; Rastogi S; Macromolecules 2017, 50 (5), 2033-2042; 6. Ronca S; Igarashi T.; Forte G.; Rastogi S.; Polymer 2017, 123, 203-210