New cross-linked polysiloxanes prepared by UV-induced thiol-ene click-reaction

A series of new cross-linked polysiloxane polymers based on functionalized cyclo- and oligosiloxane precursors was prepared by UV-induced hydrothiolation "click"-reaction using DMPA as the initiator and their physico-mechanical properties were studied. The study of a morphology of prepared polymers by scanning electron microscopy (SEM) shows that the microstructure of all samples is homogenous. The mechanical properties of all the samples were studied by the tension and compression tests. It was shown that mechanical properties of studied materials, which significantly depends on precursors nature, can be fine-tuned by changing the structure of the initial vinyl precursor. The Young's modulus varies in the range of 4.5-117 MPa in the tension test and in the rage of 6.3-209 MPa in the compression test. The tensile strength varies in the range of 0.3-3.9 MPa in the tension test and in the rage of 2.3-28 MPa in the compression test. The thermal stability of the samples was evaluated by thermal gravimetric analysis (TGA). The weight loss was observed in the range of 275-333 degrees C in air and 322-370 degrees C in argon for prepared samples. All samples were characterized by DSC method. It was shown that only DSC curves for polymers 1 and 3 contain transitions related to glass formation (-78 and -35 degrees C, respectively). All polymer samples have a similar water contact angle in the range of 90-102 degrees.