This diploma thesis deals with the measurement of mechanical properties and accelerated aging of monoaxially stretched polyethylene strips coming from three types of polymeric mesh, which serves to pack hay on baling machines. The strength of the strips is evaluated from two points of view. The first one is static tensile strength measured before and after accelerated aging at 23 °C and 40 °C, the second one determines the strength as the weight that causes the strip failure on a simple machine at 23, 40, 60 and 80 ° C. The results show that the smallest static strength has the least stabilized strip, which, on the other hand, revealed the highest strength in a dynamic loading. The change of supermolecular structure was evaluated by calorimetric measurements. The data shown only very little change of inner structure due to the average response of the whole crystalline phase comprising relatively wide distribution of crystallites. It is more than probable that supermolecular structure had been changed but the method is not sensitive to see the change of orientation of lamellae and macromolecular chains in them.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:295698 |
| Date | January 2017 |
| Creators | Huljak, Pavel |
| Contributors | Poláček, Petr, Bálková, Radka |
| Publisher | Vysoké učení technické v Brně. Fakulta chemická |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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