Low Hydrophobically Modified Poly(Acrylic Acid) Stabilizing Macroemulsions: Relationship between Copolymer Structure...

Area of Science:

• Polymer Science
• Colloid and Surface Science
• Emulsion Technology

Background:

• Hydrophobically modified polymers are utilized as effective emulsifiers.
• Understanding polymer-adsorption and solution properties is key to emulsion stability.

Purpose of the Study:

• To synthesize and characterize low hydrophobically modified linear poly(acrylic acid) sodium salts (LHMPAANa).
• To investigate the stability and flow properties of n-dodecane in water emulsions stabilized by LHMPAANa.
• To determine the influence of polymer molecular weight, degree of grafting (tau), and concentration on emulsion characteristics.

Main Methods:

• Synthesis of LHMPAANa with varying molecular weights and degrees of grafting.
• Preparation of n-dodecane in water emulsions with a dispersed phase volume fraction of 0.5.
• Investigation of emulsion stability and flow properties as a function of polymer parameters and concentration.
• Analysis of polymer adsorption at the oil-water interface.

Main Results:

• Emulsion stability is significantly influenced by the viscosification of the continuous phase due to polymer association.
• Polymer adsorption at the liquid-liquid interface is dependent on the degree of grafting (tau) but minimally affected by molecular weight.
• Molecular weight primarily impacts the viscosification of the external phase.

Conclusions:

• Both polymer adsorption and external phase viscosification are critical for a comprehensive understanding of emulsion breakdown.
• LHMPAANa's effectiveness as an emulsifier is tunable through its degree of grafting and concentration.
• The study highlights the dual role of hydrophobically modified polymers in emulsion stabilization.