Hyperbranched poly(epsilon-caprolactone) as a nonmigrating alternative plasticizer for phthalates in flexible PVC

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Chemistry

Background:

• Poly(vinyl chloride) (PVC) requires plasticizers to achieve flexibility.
• Traditional plasticizers like di(ethylhexyl) phthalate (DEHP) raise health concerns due to migration.
• Linear poly(epsilon-caprolactone) is a current polymer plasticizer with limitations.

Purpose of the Study:

• To synthesize hyperbranched poly(epsilon-caprolactone)s (HPCLs) with controlled architectures.
• To evaluate HPCLs as plasticizers for flexible PVC.
• To compare HPCL performance against DEHP and linear poly(epsilon-caprolactone).

Main Methods:

• Synthesis of HPCLs with varying linear segment lengths and branch numbers.
• Assessment of plasticization efficiency via glass transition temperature and ultimate elongation measurements.
• Evaluation of plasticizer migration using volatility, extractability, and exudation tests.

Main Results:

• HPCLs with shorter linear segments and more branches matched DEHP's flexibility.
• HPCLs significantly outperformed linear poly(epsilon-caprolactone) in enhancing PVC flexibility.
• PVC samples plasticized with HPCLs showed no plasticizer migration under harsh conditions, unlike DEHP.

Conclusions:

• HPCLs are effective plasticizers for PVC, offering high flexibility.
• HPCLs demonstrate superior performance and safety compared to DEHP and linear analogues.
• HPCLs present a viable alternative to phthalate plasticizers, mitigating health risks associated with migration.