Graduate Student Oral Presentation 1
Development of Crystalline Structure in Blends of iPP and
Isotactic Propylene-1-Alkene Random Copolymers
Hamed Janani, Rufina G. Alamo 1
1
FAMU-FSU College of Engineering, Department of Chemical and Biomedical Engineering
2525 Pottsdamer St. Tallahassee, FL 32310
Abstract
The study of melt miscibility and structure-property relations of different types of polyolefins provide an
important pathway to material design for different applications. In this work we study melt and crystalline
properties of blends of iPP and isotactic propylene-1-hexene (PH) random copolymers with 11 and 21 mol%
1-hexene, (PH11, PH21). The study of melt miscibility using thermodynamic estimations coupled with
experimental data from DSC, DMA, and AFM techniques indicate that blends of iPP/PH11 and PH11/PH21
are miscible in the melt while blends iPP/PH21 are immiscible. Depending on crystallization conditions, iPP
and PH11 may crystallize in monoclinic (α) or mesophase, and PH21 crystallizes in the trigonal phase
exclusively. The effect of isotactic sequence length distribution (ISLD) on polymorphism and crystallization
kinetics was quantitatively studied in miscible PH11/PH21 blends. An enhanced rate of formation of trigonal
phase with increasing PH11 was attributed to the increasing composition of 1-hexene in the melt during
evolution of the monoclinic phase in the first stage of isother