Table 1.

Surface chemical composition of PLA-T and PLA-MC series, as determined by XPS.

Sample	Surface Chemical Composition (Atomic %)
	C1s C-C/C-O/C = O/OC = O	O1s	Si2p/P2p/S2p/N1s/F1s/Na1s/Cl2p
Untreated PLA-T	79.4 30.4/29.2/11.7/8.0	18.3	0.8/0.3/0.2/0.7/-/0.3
Treated PLA-T	53.5 14.4/6.2/14.6/18.4	35.2	0.2/0.3/0.2/10.1/-/0.2/0.3
Untreated PLA-MC	67.0 48.0/5.1/6.5/7.4	23.3	9.0/0.4/-/-/0.3/-/-
Treated PLA-MC	43.8 14.1/7.3/10.2/12.2	40.3	9.0/0.5/0.1/5.4/0.9/-/-

PLA-T—thermoformed; PLA-MC—solution cast.