INTERFACIAL TENSION OF POLYCAPROLACTONE/POLYSTYRENE BLENDS BY THE IMBEDDED FIBER RETRACTION METHOD

Authors: Biresaw, Girma; Carriere, Craig

Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2001
Publication Date: 8/1/2002
Citation: BIRESAW, G., CARRIERE, C.J. INTERFACIAL TENSION OF POLYCAPROLACTONE/POLYSTYRENE BLENDS BY THE IMBEDDED FIBER RETRACTION METHOD. JOURNAL OF APPLIED POLYMER SCIENCE. 2002.v.40(19).p.2248-2258

Interpretive Summary: Finding new uses for agricultural commodities is an important area of research. New uses and markets for agricultural materials are needed to address the current slump in commodity prices. One application area being investigated is the replacement of petroleum-based materials with agricultural commodities such as starch and proteins from wheat and soybeans. The successful replacement of these petroleum-based materials will open new value-added markets for agricultural commodities and lessen the United States dependence on foreign oil. Many of these products will be used as blends with one or more additional materials. In order to produce blends with acceptable properties, good adhesion between materials is required. In the work reported herein, initial studies on the interaction of an experimental material, polycaprolactone, with a petroleum-based material are reported. These studies are part of an ongoing effort to address the lack of knowledge needed to develop new biobased materials.

Technical Abstract: Polycaprolactone (PCL) is a biodegradable polyester that is widely used in blends with synthetic and natural polymers for various applications. PCL is blended with biopolymers such as starch to improve its wet mechanical properties without impairing the biodegradability and other useful properties of starch. In spite of its importance, little is known about the interfacial tension of PCL blends. Indirect estimates of the room temperature interfacial tension of PCL blends using wettability methods have been reported. However, direct measurement of the interfacial tension of PCL blends have not been achieved until now, mainly due to the unsuitability of existing equilibrium methods for measuring the interfacial tension of high viscosity blends. We have measured the interfacial tension of PCL/PS blends using the imbedded fiber retraction (IFR) method. The IFR is a dynamic method that allows for the measurement of interfacial tension of high viscosity polymer blends in a relatively short period of time. The interfacial tension of PCL/PS blends was measured from 160 to 200 deg C. We found that, in this temperature range, the interfacial tension of PCL/PS blends is independent of temperature and has a value of 7.6 +/ 1.8 dyn/cm.