Hydrogels based on poly(2-hydroxyethyl methacrylate) and nettle extract

Abstract

New types of hydrogels based on linear poly(2-hydroxyethyl methacrylate) and poly(ethyleneglycol) diacrylate (PHEMA-PEGDA) and nettle extract were obtained. A solution of poly(2-hydroxyethylmethacrylate) in monomer (S-PHEMA) was obtained by bulk photopolymerization. Common nettle extractwas used as an ingredient that facilitates wound healing. The influence of the photoinitiator content(1-[4-(2-hydroxymethyl)-phenyl]-2-hydroxy-2-methylpropanone) on the photopolymerization kinetics,as well as the equilibrium swelling ratio (ESR), thermal and mechanical properties of the hydrogelswere examined. Complete HEMA conversion was achieved at the lowest photoinitiator dose. ReplacingHEMA with S-PHEMA causes an increase in ESR (24%) and Tg (50°C) and the amorphous phase content.At the same time, the tensile strength and Young’s modulus decrease. However, the addition of nettleextract (0.3 wt%) requires a significant increase in the amount of photoinitiator (up to 2.5 wt%). As theconcentration of the photoinitiator in the system increases, ESR and Tg decrease, but tensile strengthand Young’s modulus increase.