Influence of ECR-RF plasma modification on surface and thermal properties of polyester copolymer

In this paper we report a study on influence of radio-frequency (RF) plasma induced with electron cyclotron resonance (ECR) on multiblock copolymer containing butylene terephthalate hard segments (PBT) and butylene dilinoleate (BDLA) soft segments. The changes in thermal properties were studied by DSC. The changes in wettability of PBT-BDLA surfaces were studied by water contact angle (WCA). We found that ECR-RF plasma surface treatment for 60 s led to decrease of WCA, while prolonged exposure of plasma led to increase of WCA after N₂ and N₂O₂ treatment up to 70°–80°. The O₂ reduced the WCA to 50°–56°. IR measurements confirmed that the N₂O₂ plasma led to formation of polar groups. SEM investigations showed that plasma treatment led to minor surfaces changes. Collectively, plasma treatment, especially O₂, induced surface hydrophilicity what could be beneficial for increased cell adhesion in future biomedical applications of these materials.