Chain direction elastic modulus of PE crystal and interlamellar force constant ofn-alkane crystals from RAMAN measurements

On the use of supermolecule model for calculation of Young's modulus of crystalline polymers

“…Hageman et al 16 used the Car–Parrinello technique in a plane wave basis to study the elastic modulus and reported a value of 316 GPa. This value is in excellent agreement with the experiment of Pietralla et al 14. We also calculated the Young's modulus using a periodic density functional theory (DFT) [local density approximation (LDA)] code.…”

“…As Suhai 1 pointed out, the longitudinal acoustic mode observed in Raman spectroscopy is the best one to be compared to the theoretical results. The most recent Raman experiment by Pietralla et al 14 yielded a value of 315 GPa, what should be considered as the most realistic value. Introduction of electron correlation in our calculations will lead to a lower modulus that will be more in line with this result.…”

Designing Accurate Moment Tensor Potentials for Phonon-Related Properties of Crystalline Polymers

“…The elastic constants of polymers are of practical and fundamental relevance, as illustrated, for example, by the exceptionally high measured values of ~200–300 GPa for the Young’s modulus of highly oriented PE in the chain direction [ 58 , 59 , 60 ]. Moreover, the elements of the elastic stiffness tensor can be regarded as phonon-related properties, since they are intimately coupled to the group velocities of acoustic phonons via the Christoffel equations [ 61 ].…”

Crystalline Moduli of Polymers, Evaluated from Density Functional Theory Calculations under Periodic Boundary Conditions

“…The L LP value is determined from small-angle X-ray scattering. In early studies on n -paraffins with definite molecular lengths, comparatively large E ∥ values of 340 and 358 GPa were reported , and afterward, smaller E ∥ values of 260–315 GPa were evaluated for PE crystals. ,− …”

“…From the compliance tensor, the crystalline moduli (E a , E b , and E c ) and linear compressibilities (β a , β b , and β c ) in the a, b, and c axis directions and volume compressibility (β v ) of the PE −273 494 Suhai 10 −273 305 Suhai 11 −273 276, 334 Horn 12 −273 340 Crist 13 −273 336 rt c 299 Hageman 14,15 −273 334 Zhang 16 −273 360 Peeters 17 −273 340 Miao 18 −273 350−400 Cochrane 19 − 47 Raman 340 Schaufele 48 Raman 27 358 Strobl 50 Raman rt c 290 Kobayashi 49 Raman rt c 281 Tashiro 8 Raman rt c 260 Pietralla 51 Raman rt c 315 Feldkamp 52,53 neutron 20 329 Holliday 52 neutron 25 6 6 329 Twisleton 54 neutron −196 9 8…”