Investigating PVC polymer-plasticizer interactions with atomistic MD simulations and potential of mean force...

Area of Science:

• Materials Science
• Computational Chemistry
• Biomedical Engineering

Background:

• Di(2-ethylhexyl)phthalate (DEHP) is a toxic plasticizer commonly used in blood bags.
• Safer alternatives are needed to mitigate health risks associated with DEHP exposure.

Purpose of the Study:

• To investigate molecular interactions between polyvinyl chloride (PVC) and various plasticizers.
• To identify potential replacements for DEHP in blood bag applications.
• To develop a model correlating potential of mean force (PMF) profiles with interaction forces.

Main Methods:

• Atomistic molecular dynamics (MD) simulations were performed on PVC polymers (6-20 repeating units) and 14 plasticizers.
• Potential of mean force (PMF) calculations were used to quantify interaction strengths.
• A model was developed and validated to correlate PMF with plasticizer structural variations.

Main Results:

• The study ranked plasticizers based on binding affinity to PVC.
• Tris(2-ethylhexyl) trimellitate (TOTM), butyryl trihexyl citrate (BTHC), acetyl trihexyl citrate (ATHC), and bis(2-ethylhexyl)terephthalate (DEHT) showed high binding affinity.
• The developed model accurately predicted interaction forces based on PMF profiles.

Conclusions:

• TOTM, BTHC, ATHC, and DEHT are identified as promising, safer alternatives to DEHP for PVC applications.
• The findings provide insights for designing tailored polymer-plasticizer systems.
• The study supports the development of coarse-grained simulation protocols for materials science and biomedical engineering.