Elastic modulus of crystalline regions of poly(butylene terephthalate) in the direction parallel to the chain axis

Abstract

AbstractThe elastic modulus El of crystalline regions of poly(butylene terephthalate) in the direction parallel to the chain axis has been measured by the x‐ray diffraction method. Values of El for the (104) planes of the α‐ and β‐form crystal modifications were 13.5 X 104 and 21.0 X 104 kg/cm2, respectively. These values of El are very low compared with that of polyethylene terephthalate (110 X 104 kg/cm2). The results are discussed in terms of the molecular conformation in the crystalline regions.