Molecular dynamics study on the physical compatibility of SEBS/plasticizer blend systems

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Thermoplastic elastomer styrene-ethylene-butylene-styrene block copolymer (SEBS) offers excellent mechanical properties and aging resistance.
• SEBS is a promising material for thermoplastic solid propellants.
• Plasticizer selection is critical for propellant formulation and polymer compatibility.

Purpose of the Study:

• To investigate the compatibility of four different plasticizers with SEBS.
• To determine the optimal plasticizer for SEBS-based thermoplastic solid propellants.

Main Methods:

• Molecular dynamics (MD) simulations were employed using Materials Studio 8.0.
• Physical compatibility was assessed for triacetin (TA), diethyl phthalate (DEP), dioctyl sebacate (DOS), and white oil (WO).
• Simulation results were experimentally verified.

Main Results:

• The compatibility order of the plasticizers with SEBS was determined as SEBS/WO > SEBS/DOS > SEBS/DEP > SEBS/TA.
• Solubility parameters, radial distribution functions, and blend miscibility simulations were used for evaluation.
• Experimental verification confirmed the simulation findings.

Conclusions:

• The study successfully established a compatibility ranking for plasticizers with SEBS.
• White oil (WO) demonstrates superior compatibility with SEBS among the tested plasticizers.
• These findings are vital for optimizing SEBS-based thermoplastic solid propellant formulations.