| Abstract: | Compositions of neat polyproylene (PP), PP–PE (polyethylene) blend and PP–PE–DBS (dibenzylidene sorbitol) were studied with respect to their crystallization kinetics by means of differential scanning calorimetry in isothermal mode. A modified Avrami equation was applied to obtain the crystallization parameters of PP, PP–PE and PP–PE–DBS. Optical and hot-stage microscopy and dynamical analysis were used for structure determination. Experimental results have indicated that PE addition inhibits PP crystallization rate and acts as a plasticizer, while addition of DBS changes the crystallization kinetics. A detailed study of the DBS nucleation effects indicates that owing to the high surface energy, nuclei are formed during primary crystallization, leading to a fine PP crystalline structure and improved mechanical properties. |
