Characterization of a maleic anhydride-modified polypropylene as an adhesion promoter for glass fiber composites
Authors: Bogoeva-Gaceva, G.1; Janevski, A.1; Mäder, E.2
Source: Journal of Adhesion Science and Technology, Volume 14, Number 3, 2000 , pp. 363-380(18)
Publisher: VSP, an imprint of Brill
Abstract:
Isothermal and nonisothermal crystallizations of isotactic polypropylene (iPP), maleic anhydride (MAH)-grafted PP, and MAH-modified iPP were studied by differential scanning calorimetry (DSC), to evaluate the influence of a small amount of MAH-grafted PP in iPP on its crystallization behavior. Isothermal crystallization was followed in the temperature range from 391 K to 403 K, and the rate constant and Avrami exponents were determined. Nonisothermal crystallization was carried out at different cooling rates (1-20 K/min). It was found that the crystallization kinetics of iPP was significantly altered by modification with the MAH-grafted polymer. A decreased equilibrium melting temperature, as well as decreased surface energy of folding and critical dimensions of a growing nucleus, was determined for the MAH-modified iPP, indicating faster growth of lamellae and a higher rate of crystallization. The improved nucleation ability of the modified polymer was shown to cause a shift in the crystallization peak temperature towards higher values (from 393.7 K to 399.6 K, at a cooling rate of 1 K/min), resulting in crystal structures less disposed to recrystallization. Model composites of iPP and MAH-modified iPP with glass fibers were also analysed. The apparent shear strength of single-fiber model composites with MAH-modified iPP was drastically increased compared with homo-iPP.Keywords: ISOTACTIC POLYPROPYLENE; MALEINATED POLYPROPYLENE; CRYSTALLIZATION; ISOTHERMAL; NONISOTHERMAL; APPARENT SHEAR STRENGTH
Document Type: Research article
DOI: 10.1163/156856100742654
Affiliations: 1: Faculty of Technology and Metallurgy, University 'St. Cyril and Methodius', R. Boskovic 16, Skopje, Macedonia 2: Institute of Polymer Research, Hohe Strasse 6, 01069 Dresden, Germany

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