ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Blends of isotactic polypropylene with amorphous and slightly crystalline ethylene-propylene-diene terpolymer (EPDM), prepared by solution blending, have been investigated by optical microscopy and differential scanning calorimetry. Nucleation and crystallization kinetic parameters, such as nucleation rates, nucleation half times, Avrami-exponents and spherulitic growth rates, have been determined. It has been found that the dispersion of crystalline EPDM in iPP is different from that of amorphous EPDM. Both EPDMs are incorporated into the spherulites, causing a decrease of the maximum growth rate of the iPP spherulites. The surface free energy of the iPP crystals is diminished on adding EPDM to iPP and is accompanied by a higher secondary nucleation rate. From the decrease observed in the Avrami exponent with increasing EPDM concentration in the blend, it has been concluded that nucleation becomes predominantly heterogeneous, as there is a proportional increase in the interfacial area between the two components.
Additional Material:
21 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760331403
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