Origins of x‐ray line broadening in polyethylene single crystals

If multiple orders of x‐ray diffraction can be observed, the origins of line broadening in the diffraction pattern can be unambiguously assigned. In the absence of such data, rare in polymers, firm conclusions cannot be drawn. Line broadening data for single crystals of polyethylene, where multiple orders of diffraction were not observed, are consistent with the following origins: for planes with indices ( hk 0), a size of 200 A. and 1.3% strain: for the (002) plane, a size of 105 A. (in good agreement with the lamellar thickness) if 1.3% strain is assumed, or 70A. (a lower limit) if no strain is assumed.