Quantitative evaluation of iPP nucleation in the presence of carbon fibres: induction time approach
Autor: | ANITA GROZDANOV, GORDANA BOGOEVA-GACEVA, MAURIZIO AVELLA |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2002 |
Předmět: | |
Zdroj: | Journal of the Serbian Chemical Society, Vol 67, Iss 12, Pp 843-859 (2002) |
Druh dokumentu: | article |
ISSN: | 0352-5139 51454580 |
Popis: | Crystallization and nucleation behavior in model composites based on iPP and differently sized carbon fibres have been analyzed in this work. The investigations were performed in the isothermal regime (120127°C) using PLM and DSC. The results were analyzed by applying the Avrami and Muchova-Lednicky methods. It was shown that the carbon fibre surface acts as a nucleating agent during the crystallization of the iPP matrix. The highest effect was obtained with the fibres of PP-compatible size (C-T) related to unsized carbon fibres (C-U). The induction time,ti, and half-time of crystallization decreased with increasing carbon fibre content. The energy effect on the thickness of the critical nucleus decreased in the presence of C-fibres, a fact confirmed by a decrease in the nucleation parameter Q and the difference energy parameter Ds(Q decreased from 4.96 for iPP to 21.32 for C/iPP model composites, and Ds decreased from 6.14×10-7 J/cm2for iPP to 1.63×10-7 J/cm2for model composites). The results of the model composites and their comparison with published data confirmed that the Muchova-Lednicky method could be successfully applied for the quantitative evaluation of the nucleation parameters not only in the temperature range previously suggested (130 138°C), but also at lower crystallization temperatures (Tc = 121127°C). |
Databáze: | Directory of Open Access Journals |
Externí odkaz: |
načítá se...