Non-isothermal crystallization of biodegradable polymer (MaterBi)/polyolefin (PP)/hemp fibres ternary composites

C. J. PÉREZ; V. ALVAREZ

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

SPRINGER

Lugar: Berlin; Año: 2015 vol. 120 p. 1445 - 1455

1388-6150

The non-isothermal crystallization of biodegradable thermoplasticmatrix, Mater-Bi® (MB) and polypropylene (PP) blends were studied usingdifferential scanning calorimetry (DSC). Hemp fibres was used as filler and maleicanhydride functionalized polypropylene (PP-g-MAH) was employed as compatibilizer.MB forms immiscible blends with PP. Both, the dispersed phases of moltenMB acts as nucleating agents enhancing the crystallization rate of PP and thesolidified PP act as nucleating agents to enhance the crystallization of MB.The values of half-time of crystallization (t1/2) and theparameter Zc , from Avrami`s method which characterize the kineticsof non-isothermal crystallization, showed that the crystallization rate, at thesame cooling rate, decreased with the fibres and increased with the PP-g-MAH; showing the retarding and acceleratingeffects respectively.Some models,such as the Liu-Mo and Avrami, were found to provide a fairly satisfactorydescription of the crystallization kinetics of the studied blends. Theseresults are further supported by the effective activation energy calculationsby iso-conversional method of Friedman.