Table 6.

SFE values for repeated synthesis PU films

Sample No.	Substrates			\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \gamma_S^{\exp } $$\end{document} (mJ/m2)
	Type of diisocyanate	Type of polyol (molecular weight)	Type of chain extender
11	1	2	5	36.78
18	2	2	1	28.73
32	4	2	4	45.32
34	4	3	4	36.91a

^aThe result with more bigger error remains decline