REAL

Comparison of different beta-nucleators for isotactic polypropylene, characterisation by DSC and temperature-modulated DSC (TMDSC) measurements

Kállay-Menyhárd, Alfréd and Varga, József and Molnar, G. (2006) Comparison of different beta-nucleators for isotactic polypropylene, characterisation by DSC and temperature-modulated DSC (TMDSC) measurements. JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, 83 (3). pp. 625-630. ISSN 1388-6150

[img] Text
1218826.pdf
Restricted to Repository staff only

Download (901kB) | Request a copy

Abstract

The nucleating efficiency and selectivity of different beta-nucleating agents was characterised and compared by differential scanning calorimetry, (DSC) and temperature-modulated DSC (TMDSC). The nucleating agents were the calcium salts of pimelic and suberic acid (Ca-pim and Ca-sub), linear trans-gamma-quinacridone (LTQ), a commercial nucleator NJ Star (NJS) and an experimental product (CGX-220). The efficiency and the selectivity of Ca-sub and Ca-pim are extremely high. NJS is efficient above a critical concentration, which is connected with its partial dissolution in polypropylene melt. LTQ and CGX-220 possess strong overall nucleating ability and moderate selectivity. Using TMDSC, we found that three consecutive processes take place during the heating of beta-nucleated samples cooled down to room temperature: reversible partial melting of the beta-form, irreversible beta alpha- recrystallisation, and the melting of the alpha-modification formed during beta alpha- recrystallisation or being present in samples prepared with non-selective beta-nucleators. Melting of the alpha-phase contains both reversible and irreversible components.

Item Type: Article
Additional Information: European Conference on Calorimetry and Thermal Analysis for Environment SEP 06-11, 2005 Zakopane, POLAND
Uncontrolled Keywords: calorimetry, crystallisation, efficiency, isotactic polypropylene, melting, α-modification, β-modification, β-nucleators, recrystallisation, selectivity, temperature-modulated DSC
Subjects: Q Science / természettudomány > QD Chemistry / kémia
SWORD Depositor: MTMT SWORD
Depositing User: MTMT SWORD
Date Deposited: 05 Mar 2014 12:32
Last Modified: 05 Mar 2014 12:33
URI: http://real.mtak.hu/id/eprint/10690

Actions (login required)

Edit Item Edit Item