Thermoplastic Dynamic Vulcanizates with In Situ Synthesized Segmented Polyurethane Matrix

Area of Science:

• Polymer Science
• Materials Science

Background:

• Thermoplastic polyurethanes (TPUs) are versatile polymers with tunable properties.
• Thermoplastic dynamic vulcanizates (TDVs) offer a unique combination of thermoplastic processability and elastomeric performance.
• Developing TDVs with improved interfacial adhesion and controlled morphology is crucial for advanced applications.

Purpose of the Study:

• To investigate the properties of TPUs polymerized in situ and their use as matrix polymers for TDVs.
• To explore the effect of different rubber types (NBR, XNBR, ENR) and processing conditions on TDV properties.
• To enhance the interfacial connection between the rubber phase and the TPU matrix through in situ synthesis.

Main Methods:

• In situ synthesis of TPU matrix during dynamic vulcanization in an internal mixer.
• Utilizing NBR, XNBR, and ENR as the rubber phase.
• Characterization using tensile testing, DMTA, AFM, SEM, and DSC.

Main Results:

• The optimal processing temperature for TDV production was determined to be 125 °C.
• AFM indicated phase separation within the TPU matrix and even rubber phase distribution.
• SEM revealed rubber particle agglomeration forming a quasi-continuous phase, reversibly broken by heat/shear.
• The produced TDVs demonstrated mechanical properties comparable to commercial TDVs of similar hardness.

Conclusions:

• Processing temperature significantly impacts TDV properties, with 125 °C being optimal.
• The in situ synthesis approach allows for controlled morphology and potentially improved interfacial interactions.
• The resulting TDVs exhibit promising mechanical performance suitable for various applications.