Table 5. FT-IR Spectrum Peak Attributions for SLL.

wavenumber range/cm–1	peak number	wavenumber/cm–1	area/%	attribution
3600–3000	1	3429	77.58	phenolic hydroxyl
	2	3220	22.42	alcohol hydroxyl
3000–2800	1	2955	16.55	RCH3 symmetric stretching
	2	2922	44.03	R1CH2R2 anti-symmetric stretching
	3	2889	15.85	RCH3 symmetric stretching
	4	2853	23.57	R1CH2R2 symmetric stretching
1700–900	1	1634	7.79	COO– anti-symmetric stretching
	2	1585	5.40	aromatic ring skeleton
	3	1519	1.20	aromatic ring skeleton
	4	1448	4.65	aromatic ring skeleton
	5	1383	4.28	C–O on phenol
	6	1322	3.20	C–O on phenol
	7	1270	4.12	C–O on phenyl ether
	8	1217	4.66	C–O on phenol
	9	1161	12.61	C–O on phenyl ether
	10	1100	30.14	C–O on aliphatic ether
	11	1039	11.35	C–O on acid anhydride
	12	1017	10.60	C–O on aliphatic ether
810–660	1	799	25.93	tri-substituted aromatics
	2	788	9.52	tri-substituted aromatics
	3	778	20.13	tri-substituted aromatics
	4	765	4.14	di-substituted substitutions
	5	751	2.86	di-substituted aromatics
	6	705	4.87	mono-substituted aromatics
	7	694	12.25	mono-substituted aromatics