New Biobased Plasticizers for PVC Derived from Saturated Dimerized Fatty Acids

Area of Science:

• Polymer Science
• Materials Chemistry
• Green Chemistry

Background:

• Phthalates, widely used as PVC plasticizers, pose significant health and environmental risks as endocrine disruptors.
• There is a growing market demand for sustainable, non-toxic plasticizers due to legislative changes and environmental concerns.
• Traditional phthalate plasticizers face increasing scrutiny, necessitating the development of safer alternatives.

Purpose of the Study:

• To synthesize and characterize novel biobased oligoesters as potential replacements for phthalate plasticizers in poly(vinyl chloride) (PVC).
• To evaluate the compatibility, plasticizing efficiency, and performance properties of these new oligoesters in PVC formulations.
• To compare the properties of the novel biobased plasticizers with commercially available phthalate plasticizers.

Main Methods:

• Oligoester synthesis via polyesterification of dimerized fatty acid (DFA), adipic acid (ADA), triethylene glycol (TEG), and 2-ethylhexanol (2-EH).
• Characterization using nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), and viscosity measurements.
• PVC film preparation by casting, followed by testing for plasticizer migration, hardness, thermal stability (TGA, DSC), and mechanical strength.

Main Results:

• Oligoesters synthesized at a 9:1 molar ratio of ADA to DFA with excess 2-EH demonstrated excellent compatibility and plasticizing performance in PVC.
• Increased DFA content negatively impacted oligoester compatibility with PVC.
• A 4:1 ADA-to-DFA ratio yielded oligoesters suitable for use at lower concentrations or in blends.

Conclusions:

• Biobased oligoesters derived from DFA and ADA show significant potential as environmentally friendly and non-toxic plasticizers for PVC.
• Optimized synthesis ratios are crucial for achieving desired compatibility and performance in PVC applications.
• These novel oligoesters offer a sustainable alternative to conventional phthalate plasticizers, aligning with green chemistry principles.