Relation of joint strength and polymer molecular structure in laser assisted metal and polymer joining

The study of laser assisted metal and polymer joining has been conducted to identify the mechanism of the hybrid joint. The bonding mechanism has been revealed to be due to the expansion pressure of pyrolysis fragments. Previous research has dealt with superficial factors without consideration of the polymer thermal decomposition phenomenon, which is the major factor of the joining strength. With experiments and simple chemical analysis for simple structured polymers this paper presents the quantitative relationship among the joint strength, the expansion pressure, the gas fragment composition, and the molecular structure. To verify the relation of the joint strength and the polymer molecular structure, the results were analysed and compared with the results of previous studies. Correlation of the quantified joint strength and the quantified expansion pressure and the monomer yield is also defined. The results confirm that the joint strength is correlated with the polymer structure.