Adhesion Enhancement of Chlorosulfonated Polyethylene via Self-Interface Roughening on Aluminum Substrate.

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Adhesion between polymers and metals is crucial for many applications.
• Chlorinated polyethylene (CPE) has limited adhesion to aluminum (Al).
• Investigating novel polymers for improved metal adhesion is essential.

Purpose of the Study:

• To investigate the adhesion mechanism of chlorosulfonated polyethylene (CSM) to aluminum (Al).
• To compare the adhesion strength of CSM-Al with chlorinated polyethylene (CPE)-Al.
• To identify the role of the chlorosulfonyl (SO₂Cl) group in enhancing adhesion.

Main Methods:

• Lap-shear strength testing to quantify adhesion.
• Scanning transmission electron microscopy with electron energy loss spectroscopy (STEM-EELS) for interface analysis.
• Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) for surface characterization.
• Ellipsometry to study adsorbed polymer layers.

Main Results:

• CSM-Al lap-shear strength was nearly 3 times higher than CPE-Al.
• CSM created a rough interface with a thick Al(OH)₃ oxide layer.
• Adhesion enhancement is linked to electrochemical reactions involving chloride ions and Al oxide.
• CSM exhibited more loosely adsorbed polymer chains acting as connection points.

Conclusions:

• The chlorosulfonyl (SO₂Cl) group significantly enhances CSM adhesion to aluminum.
• Interfacial roughness and loosely adsorbed polymer chains are key to improved bonding.
• CSM-based polymers may serve as effective adhesives without surface pretreatment.