Melting Behaviour of Polypropylene Fibres Studied by DSC
| Title |
Melting Behaviour of Polypropylene Fibres Studied by DSC |
| Publication year |
1994 |
| Language |
English |
| Author |
Hinrichsen, Einar L. |
| Co-Authors |
Andreassen, Erik - Grøstad, Kristin - Myhre, Ole Jan (Norner) |
| Source |
14th Nordic Symposium on Thermal Analysis and Calorimetry (NSTAC-14), Oslo, Norway, 15.-17. June, 1994 |
| Abstract |
The properties of a polypropylene fibre are related to the thermomechanical history of the fibre, which can be described as a combination of deformation ratios, rates and temperatures. Available processes offer a wide range of fibre dimensions and properties. DSC analyses of fibres provide fingerprints of the processing history, and of the molecular weight distribution of the polymer. By statistical methods, DSC thermograms can be "calibrated" to yield information that otherwise only can be obtained directly by techniques such as x-ray diffraction. DSC analyses also have more direct applications, such as assessing the bondability of fibres to be used in thermobonded nonwoven fabrics. DSC thermograms obtained for oriented polymers are generally not well understood. Different interpretations can be found in the literature. One of the debated issues is to what extent structural reorganisations during heating influence the thermograms. Special techniques such as modulated DSC and swelling DSC might be helpful in this respect. The onset of melting, and the width and the shape of the endotherm, depend on the processing conditions, the preparation technique, and the heating rate. Some processing conditions lead to endotherms with several maxima. This presentation will focus on effects of processing conditions and molecular weight distribution on the thermograms. The results will be discussed in terms of structure, structural restraints and reorganisation. |