Effect of Thermal Cycle on the Relative Variations of Thermal Properties and Crystalinity of (PP/EPR)/CaCO3 Mixtures

The objective of this chapter is to investigate the relative variations of the constants of the thermal properties and the degree of crystallinity of the mixtures (PP/EPR)/Calcium carbonates elaborated with the Micro Bivis. Three calcium carbonates models socal312, socal322v, and Winnofil spm were used to reinforce the basic copolymer PP/EPR at a low level (5%). The varied combinations were then exposed to two cycles of thermal loading using differential scanning calorimetry DSC. We finally focused on the thermal properties of isotactic polypropylene (TfP, TcP, HfP, HcP) and we calculated the degree of crystallinity of the mixtures. One of the goals of this project is to lower the energy cost of applying mixtures. The relative variations of the aforesaid properties with those of the base copolymer were quantified. It demonstrates that at a low loading rate of calcium carbonate, there is a decrease in the enthalpies of crystallization during the second exothermic cycle, with values that can reach 5,53 J/gPP for the basic copolymer PP/EPR. The isotactic polypropylene melting temperature values for all blends, as well as the basic copolymer PP/EPR, increase during the second endothermic cycle. Even at a modest loading rate for the majority, calcium carbonates have been shown to reduce the melting energy of isotactic polypropylene. The number of endothermic cycles accentuates this phenomenon which is linked to the presence in our composites, of a so-called confined amorphous phase.