['Their', 'model', 'has', 'the', 'energy', 'contribution', 'due', 'to', 'intrachain', 'interactions', 'only', 'and', 'the', 'dominant', 'driving', 'force', 'for', 'crystallization', 'is', 'entropic', ',', 'which', 'seems', 'to', 'ignore', 'dominant', 'driving', 'force', 'for', 'polymer', 'crystallization', 'in', 'conventional', 'sense', '.']