Mechanical properties of two crystalline modifications of poly-1-butene

Two crystalline modifications of poly-1-butene obtainable from melt can be easily identified by infrared spectroscopy or differential scanning calorimetry. The latter technique was used in this work to characterize samples crystallized from the melt and used for measurement of mechanical properties (modulus, yield point, elongation and tensile strength at the break). The mechanical properties are related to the modification of crystalline structure which changes from modification II to modification I, including transient mixtures of these two modifications. The effect of radiation on mechanical properties of modification I was studied and attributed to the effect on crystallinity and molecular weight distributions. (author)