Thermal and rheological behavior of reactive blends from metallocene olefin elastomers and polypropylene

Nei S Domingues Junior,Maria M De C Forte,Izabel C Riegel

doi:10.1590/s0104-14282012005000030

Nei S Domingues Junior, Maria M De C Forte + Show 1 more

Open Access

https://doi.org/10.1590/s0104-14282012005000030

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Abstract

Reactive blends of metallocene polyolefin elastomers (POE)/polypropylene (PP) with 60/40 composition were prepared with an organic peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, and a bis-azide derivative, diphenyloxid-4,4'-bis(sulfonylazide) (BSA). Ethylene-1-butene (EB) and ethylene-1-octene (EO) copolymers and elastomeric polypropylene (ePP) were used as the elastomeric phase. The effect of elastomeric phase on the thermal, rheological, morphological and mechanical properties of the thermoplastic vulcanizates (TPVs) or dynamic vulcanizates were studied. All TPVs depicted pseudoplastic behavior and blends cured with azide curative showed higher viscosities. The TPVs showed both dispersed and continuous phase morphology that depends on the elastomeric phase type revealing a limited degree of compatibility between PP and the elastomers EO or EB. On the other hand, the TPV PP/ePP showed a uniform morphology suggesting an improved compatibility. Substantial changes observed in physical properties were explained on the basis of blends' morphology and dynamic vulcanization. The results confirm that the mechanical properties are more influenced by the elastomeric phase than by the curative agent. This study revealed a broad new range of opportunities for POE-based TPVs.

Highlights

This study revealed a broad new range of opportunities for polyolefin elastomers (POE)-based Thermoplastic Vulcanizates (TPVs)
The present study focuses on the properties of blends using random polypropylene copolymer (PP) as the hard component and polyolefin elastomers (POE) as the soft ingredient
The properties of POE/PP blends and dynamic vulcanizates were studied as function of the elastomeric component (EO, EB and elastomeric polypropylene (ePP)) and crosslinking agent type

Summary

Introduction

Thermoplastic elastomers (TPEs) based on rubber and plastic ethylene-propylene-diene terpolymer/polypropylene (EPDM/PP)blends are materials that combine properties of thermoplastic pair had presented the best balance of physical properties and and elastomeric materials, not achievable by other means. achieved the biggest commercial significance[9,10], calling attention Thermoplastic Vulcanizates (TPVs) – a sub-class of TPEs[1], of many industrial players and a large number of academic are engineering materials obtained by blending elastomeric researchers[11,12,13,14,15,16,17,18,19,20,21,22,23].and plastic polymers through a process called dynamicThe advent of Metallocene Single-site Constrained geometry vulcanization[2]. New polymer families of the crosslinked elastomer can became the dispersed phase with ethylene α-olefin copolymers with elastomeric behavior are dimensions on the order of 1 μm, immersed in the thermoplastic commercially available, reported as impact modifiers for matrix.

Results

Conclusion