Synthesis and characterization of functionalized amphiphilic polymers for utilization as surfactants

ABSTRACT

Eight novel PEG-based amphiphilic block copolymers having self-assembling properties has been reported in the present study. The polymers have been synthesized by reacting Poly(ethylene glycols) (PEGs) of different molecular weights viz. 600, 1000, 1500 and 2000 and dimethyl-5-hydroxyisophthalate in presence of concentrated H₂SO₄ as catalyst in solventless condition at 80–90°C and further alkylating the resulting polymers by attaching octyl and hexadecanyl chains to phenolic hydroxyl group. The resulting functionalized amphiphilic polymers have been characterized by ¹H and ¹³C-NMR spectroscopy. These polymers, when dissolved in water, aggregate to form micelles, giving sizes ranging from 13.00 to 87.24 nm as determined by Dynamic Light Scattering (DLS) instrument. The molecular weights have been also calculated from the DLS and are in the range 3.5×10⁴ to 1.8×10⁶ KDa (Kilo Daltons). Critical Micelle Concentrations (CMC) of the synthesized polymers was determined using electrical conductivity meter with values in the range of 105 to 138 mg L⁻¹ (milligrams per litre).

KEYWORDS:

• ¹H and ¹³C-NMR
• CMC
• poly(ethylene glycols)
• amphiphilic polymers
• bromooctane
• bromohexadecane
• dimethyl 5-hydroxyisophthalate
• DLS
• TEM

Acknowledgments

The authors thank the Head, Division of Agricultural Chemicals, IARI, New Delhi for providing facilities to carry out the research work.

Funding

S. M. Majumder thanks the PG School, IARI, New Delhi, for financial support.