Charakterisierung des Einflusses von variierenden Prozessparametern beim Presssintern auf die Eigenschaften von ultrahochmolekularem Polyethylen (UHMWPE)
Research output: Thesis › Master's Thesis
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Abstract
Within this thesis the effect of the sintering parameters pressure, temperature and time at compression moulding on the mechanical and morphological characteristics of ultra-high molecular weight polyethylene (UHMWPE) films with differing molecular weight was analyzed. By measuring the gel content the degree of cross-linking of the films was evaluated. The degree of crystallinity was analyzed by Differential Scanning Calorimetry (DSC). Thermo-oxidative degradation was characterized by DSC and Infrared-Spectroscopy. The sample morphology was characterized applying Scanning Electron Microscopy (SEM). Tensile tests yielded the relevant mechanical properties strain at break and stress at break. Independent on the processing parameters weight an increase of the gel content and the stress at break and a decrease of the strain at break and the crystallinity with increasing molecular of the samples were ascertained. Morphological investigations revealed stronger surface irregularities along with numerous defects for films produced from grades with higher molecular weight. With increasing sintering pressure a slight decrease of the crystallinity of the samples was observed. However, the sintering pressure did not affect the mechanical characteristics of the samples. An increase of the sintering temperature yielded an increase of the gel content, the strain at break and the stress at break. The sample crystallinity was not affected by the sintering temperature. Surface irregularities and defects were found to decrease with increasing sintering temperature. With increasing sintering time no significant changes of the gel content, the crystallinity, the strain at break and the stress at break were detected. Moreover, even at high sintering times no thermo-oxidative degradation of the samples was ascertained, which is an indication for high temperature stability of the investigated UHMWPE grades. Surface irregularities and defects were found to decrease with increasing sintering time.
Details
Translated title of the contribution | Characterization of the effect of varying process parameters at compression moulding on the properties of ultra-high molecular weight polyethylene (UHMWPE) |
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Original language | German |
Qualification | Dipl.-Ing. |
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Award date | 17 Dec 2010 |
Publication status | Published - 2010 |