Characterization of a Poly(propylene-g-styrene) Graft Copolymer by Temperature Rising Elution Fractionation

Abstract

A polystyrene-grafted polypropylene sample was prepared by solid-state grafting polymerization in the presence of 2,2,6,6-tetramethyl-piperidinyloxy. Temperature rising elution fractionation of the grafted PP was performed and the fractions were characterized by ¹H- and ¹³C-NMR, FT-IR, GPC, DSC, and WAXD. Results show that the grafted PP fraction eluted at 114°C accounts for 42% of the graft copolymer and has the highest grafting degree, high melting temperature and crystallinity, and high molecular weight. All the phenomena suggest that the grafted polymer contains a major component that has low branch density and long branch chain and a minor component with high branch density and short branches.

Keywords:

• 2,2,6,6-Tetramethyl-piperidinyloxy
• Isotactic polypropylene
• Solid-state graft polymerization
• Styrene
• Temperature rising elution fractionation

Support by the National Natural Science Foundation of China (grant no. 20474053) and Major State Basic Research Programs (grant no. 2005CB623804) is gratefully acknowledged.

Notes

^a Melting temperature.

^b Degree of crystallization.

^c Enthalpy of melting.

^d Crystallization peak temperature.