Supermolecular Structure of Polypropylene Fibres Modified by Additives
Research and development
Authors:
- Broda Jan
Institute of Textile Engineering and Polymer Materials, University of Bielsko-Biala, Bielsko-Biała, Poland - Gawłowski Andrzej (j/w)
- Fabia Janusz (j/w)
- Ślusarczyk Czesław (j/w)
 Full text | Abstract: The most common procedure for the modification of polypropylene fibre involves adding additives, which are incorporated into polymer by physical means during fibre formation. Particles of the additives blended with polypropylene melt cause a change in the structural parameters of the fibres. The influence of flame retardants and pigments has been investigated. It was stated that the effect of additives on the fibre structure is based on two mechanisms. The first mechanism is encountered for flame retardants, which do not reveal a nucleating ability toward polypropylene crystallisation. Fibre formation flame retardants affect the melt viscosity and consequently molecular orientation. As a result, a more ordered structure is formed. Contrary to flame retardants, pigments reveal a nucleating ability toward polypropylene crystallisation. During fibre formation low extrusion velocity pigments participate in the nucleation process. Then a high crystalline structure is formed in fibres. At higher take-up velocities the crystallisation process is dominated by a high molecular orientation and the heterogeneous nucleation on pigments loses its importance. |
Tags: polypropylene fibre, supermolecular structure, crystallisation, flame retardant, pigment.