Sub-Product

Flexible Polypropylene Copolymers constitute a new family of mostly random copolymers of Propylene and Ethylene, which appeared on the market in 2004. 

They came into existence thanks to the combination of solution polymerization processes (that were initially developed for ethylene copolymerization) with a new generation of proprietary, high-selectivity single-site catalysts.

They are predominantly semi-crystalline copolymers of ethylene and propylene with from 5% to less than 20 wt%, more commonly 10 to 16% of ethylene comonomer. The higher the ethylene content, the lower the density and the more flexible they are.  

The structure of the propylene segments is predominantly isotactic-stereoregular resulting in isotactic propylene crystallinity.

Depending on the ethylene content, the density of these copolymers spans a range from 0.856 to 0.89 g/cm³, which is the reason why they may be defined as either Polyolefin Elastomers (POEs) and Polyolefin Plastomers (POPs) although their composition is strikingly different, which is the reason why we suggest to define them as Polypropylene Elastomers (PPE) and Polypropylene Plastomers (PPP).

However, they are comprised in one single category since there is no compositional difference but a continuum concentration gradient of C₂ and C₃ comonomers, to the contrary of clearly differentiated C₄-based elastomers and C₈-based plastomers.