Foam extrusion of modified bioplastic on basis of polylactide (PLA)

• Applicants: Professor Dr.-Ing. Volker Altstädt; Professor Dr.-Ing. Christian Bonten
• Subject Area: Plastics Engineering
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 379522332

Foams are characterized by very low density, very low thermal conductivity, high sound absorption and low tooling costs. Most foamed moldings are used in relatively short-living transport packaging, e.g. electronic devices and in insulation applications. Polylactide (PLA) is a biodegradable and biobased plastic, which is produced in commercially significant amount of cost-effective lactic acid. In order to provide additional disposal option for foamed packaging after the lifetime and/or to scarce fossil resources, it is desirable to establish extrusion foams on the basis of PLA. Due to its low melt strength, this is not currently possible. Despite several approaches to increase the melt strength through long chain branching there are several open questions to the conformation of long chain braching. The aim of the projected research project here is to clarify open questions regarding various zero viscosities, different numbers of functional groups, different reaction mechanisms of modification and interactions in blends of linear and modified PLA to increase its melt stiffness and thus to enable the extrusion foaming.

• DFG Programme: Research Grants