Phase structure and morphology of wollastonite‐reinforced polypropylene composites modified with SEBS and SEBS‐g‐MA elastomers

Abstract

Supermolecular structure of isotactic polypropylene/wollastonite/styrenic rubber block copolymers composites were studied as a function of elastomeric poly‐ (styrene‐b‐ethylene‐co‐butylene‐b‐styrene) triblock copolymer (SEBS) and the SEBS grafted with maleic anhydride (SEBS‐g‐MA) content (from 0 to 20 vol%) by optical, scanning, and transmission electron microscopy, wide‐angle X‐ray diffraction and differential scanning calorimetry. Wollastonite particles disturbed the spherulitization of polypropylene matrix. Both elastomers affected the crystallization of polypropylene matrix mainly by solidification effect. Although SEBS‐g‐MA encapsulated wollastonite particles more expressive than SEBS forming thus core‐shell morphology in higher extent, scanning electron micrographs indicated more constrained wollastonite particles in fractured surfaces of composites with SEBS elastomer. Moreover, SEBS‐g‐MA disorientated wollastonite particles and affected reorientation of the polypropylene crystallites stronger than SEBS elastomer. POLYM. ENG. SCI., 47:2145–2154, 2007. © 2007 Society of Plastics Engineers

Nucleation of Polypropylene Homo- and Copolymers

“…To obtain a suitable stiffness/impact balance in mineralfilled polypropylenes, elastomer can be added to polypropylene containing calcite (Premphet and Horanont, 2000) or wollastonite (Svab et al, 2007). A paper by Kolarik and Jancar (1992) offers two different routes to the final structure of a compound containing calcite when there are approximately the same amounts of both components in PP.…”

Biaxial deformation behavior and mechanical properties of a polypropylene/clay nanocomposite

“…Samples ranging between 6 and 10 mg were heated from 20°C to 220°C at a heating rate of 10°C/min, held at 220°C for 2 min, then cooled from 220°C to 20°C at a cooling rate of 10°C/min. Enthalpy of fusion of 100% crystalline PP (DH f ) was taken as 148 J/g [17].…”

Polypropylene/combinational inorganic filler micro‐/nanocomposites: Synergistic effects of micro‐/nanoscale combinational inorganic fillers on their mechanical properties

“…3). One of the possible reasons can be the synergistic effect of different morphologies of the filler particles of WT 31, 41. Such synergistic effect is probably through an engaging mechanism between plate‐like talc particles and needle‐like wollastonite particles.…”

“…Modification of PP with organic elastomers is an effective way to improve the toughnesses of PP‐matrix materials, but their moduli usually decrease obviously 25–27. To reach a good balance between strengths, moduli, and toughnesses, scientists have designed polynary systems ( i.e ., nano‐CaCO 3 /SBS/PP, PP/POE/BaSO 4 , PP/EOR/CaCO 3 , PP/EPDM/nano‐CaCO 3 , and PP/SEBS‐ g ‐MA/wollastonite), consisting both of inorganic fillers and of organic elastomers to reinforce PP‐matrix materials 28–32. One should note that such polynary systems are complex and expensive in material preparation.…”

“…Coupling agents, compatibilizers, and irradiation grafting polymerization have been usually used to modify the surfaces of inorganic fillers and consequently to enhance the affinity and bonding strength between inorganic fillers and organic matrices 11, 18, 23, 33, 34, 38–49. Particle sizes and morphologies of inorganic fillers are also found to be important factors that influence the properties of polymer composites 20–24, 31, 32, 41, 42, 50, 51. In addition, uniform dispersion of the filler particles in polymer matrices has been a precondition of achieving an effective reinforcement 39.…”