Christian G’Sell of CNRS: Dependence of fracture toughness of a compatibilized polypropylene/polyamide blend to the local mechanisms of plastic deformation

DEPENDENCE OF FRACTURE TOUGHNESS OF A COMPATIBILIZED POLYPROPYLENE / POLYAMIDE BLEND TO THE LOCAL MECHANISMS OF PLASTIC DEFORMATION

Christian G’SELL
Professor Emeritus
Institut Jean Lamour (CNRS)
Ecole des Mines de Nancy (France)

Date / Time: February 23 (Wednesday) / 2:00 – 3:30pm
Place: C-205, Schmitt Hall

Abstract

Although polypropylene (PP) is a very versatile plastic with lots of practical applications, it suffers somehow from its critical brittleness under tensile loading, due to the relatively high value of the glass-transition temperature. This is the reason why
it is often filled with rubbery particles that provide it with an improved toughness. Despite this positive result, such “high impact PP” blends present an insufficient Young’s modulus. In this work, we developed a new family of PP-based materials that: i) keeps the modulus and the yield stress as close as possible to their original values for neat PP and, ii) increases the impact strength as much as possible. The key of this improvement was to blend the PP with polyamide 6 (PA6) that is known for its excellent behavior under uniaxial tension. Since PP and PA6 show some reciprocal allergy, some quantity of a thermoplastic elastomer (polyethylene-octene, POE) was added to form a ternary system. Mechanical tests, including Izod impact tests and tensile tests at constant true strain rate (with the VidéoTraction ? system invented by the author) proved that the aimed properties were correctly attained. These properties are discussed in terms of the local mechanisms of plastic deformation in the system on the basis of transmission electron micrographs. It is thus shown that, in blends, each of the three components plays its role with the others in a synergistic way

Advertisements

About ateneophysicsnews
Physics News and Features from Ateneo de Manila University

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: