(3-Acryloxy-2-Hydroxypropoxypropyl) Terminated Polydimethylsiloxane

Zhang, Wei, et al. Polymers for Advanced Technologies 29.7 (2018): 2103-2109.

The hydrophilic modification of the surface of polymer polydimethylsiloxane (PDMS) is a key step in its application in biomaterials, bioengineering and other fields. In this paper, a novel and effective method is proposed to reverse the hydrophobic surface by one-step hydrolysis of Si-O bonds to produce hydrophilic hydroxyl groups. The hydrophilizing agent 2-(trimethylsiloxy)ethyl methacrylate (TMSEMA) is used for the copolymerization of (3-Acryloxy-2-Hydroxypropoxypropyl) Terminated Polydimethylsiloxane. The prepared PDMS film is subjected to a one-step surface hydrophilic reversal treatment using KOH solution to produce hydroxyl groups on the surface. Contact angle, attenuated total reflection Fourier transform infrared spectroscopy, and equilibrium water content (EWC) of PDMS films are measured. The results show that the TMSEMA content has no significant effect on the contact angle and EWC value of the untreated PDMS. Contact angle after inversion treatment When the TMSEMA content was 15 wt%, the EWC value decreased from 94° to 15°, and the EWC value increased to 10%. The spectrum proved that the reverse reaction produced hydroxyl and carboxylate groups on the surface.
(3-Acryloxy-2-Hydroxypropoxypropyl) Terminated Polydimethylsiloxane and hydrophilic agent TMSEMA were added to the flask at a specific temperature. Then the crosslinker EGDMA and the photoinitiator D-1173 were added in sequence. The formulation mixture was stirred for 12 h at room temperature (25°C) and protected from light. Then, the mixture was injected into a double-layer polypropylene mold and UV (≥15 mV/cm) was kept at the same temperature for 2 h. After the copolymerization reaction was completed, the obtained PDMS film was stored in phosphate buffered saline for the next experiment.