New polymers with tuneable dielectric properties were prepared by modifying trimethylsilyl end-terminated poly(methylhydro)siloxane with polar γ-cyanopropyl groups. The amount of polar groups was tuned by adjusting the allyl cyanide/n-hexene ratio in poly(methylhydro)siloxane co-hydrosilylation. The copolymers were characterized by FTIR and NMR spectroscopy. The distribution of the polar groups along the chain was evaluated based on ¹H NMR spectroscopy. The influence of the amount of polar γ-cyanopropyl on the glass transition temperature (T_g) and on the dielectric properties was investigated by DSC and impedance spectrometry. All polymers showed T_gs well below room temperature. A linear increase in permittivity (ε′) with increasing amount of γ-cyanopropyl groups was observed. A maximum ε′ value of 15.9 for the copolymer containing 89 mol% polar groups was achieved, which is 6-fold higher than polydimethylsiloxane. The incomplete conversion of Si–H groups observed in all hydrosilylation reactions with allyl cyanide opened up the possibility of using the prepared copolymers as cross-linkers.

The excellent biological properties of chitosan (CS) together with the increased oxygen permeability of polyvinyl alcohol (PVA) were the prerequisites for the creation of a wound healing dressing that would also function as a system for L-arginine (L-arg) and caffeine (Caff) delivery. Using the freezing/thawing method, 12 hydrogels were obtained in PVA:CS polymer ratios of 90:10, 75:25, and 60:40, and all were loaded with L-arg, Caff, and the mixture of L-arg and Caff, respectively. Afterwards, an inorganic material (zeolite–Z) was added to the best polymeric ratio (75:25) and loaded with active substances. The interactions between the constituents of the hydrogels were analyzed by FTIR spectroscopy, the uniformity of the network was highlighted by the SEM technique, and the dynamic water vapor sorption capacity was evaluated. In the presence of the inorganic material, the release profile of the active substances is delayed, and in vitro permeation kinetics proves that the equilibrium state is not reached even after four hours. The synergy of the constituents in the polymer network recommends that they be used in medical applications, such as wound healing dressings.

Polydimethylsiloxane-α,ω-diols were used as matrix for barium titanate particles to obtain electroactive elastomeric composites. Filler particles were previously treated with a surfactant to improve the compatibility with and dispersibility in the matrix. The composites, processed as films and crosslinked with methyltriacetoxysilane, were investigated from point of view of the morphology, moisture sorption and thermal properties, as well as mechanical and dielectric behavior. Maximum strain value of 850% at 0.32 MPa and dielectric permittivity of 4.41 at 10 Hz and 20 °C were obtained. Two parameters of interest for potential future application of such materials in electromechanical devices (actuation or harvesting), electromechanical sensitivity and harvesting energy capacity, were estimated and discussed in correlation with the molecular mass of the polymeric matrix and the content of the active filler

Dielectric elastomers were prepared on the basis of high molecular weight polydimethylsiloxane-α,ω-diol filled with barium titanate particles having well-defined size and morphology.

Here we present a new biomaterial based on cellulose, collagen and polyurethane, obtained by dissolving in butyl imidazole chloride. This material served as a matrix for the incorporation of tannin and lipoic acid, as well as bioactive substances with antioxidant properties. The introduction of these bioactive principles into the base matrix led to an increase of the compressive strength in the range 105–139 kPa. An increase of 29.85% of the mucoadhesiveness of the film containing tannin, as compared to the reference, prolongs the bioavailability of the active substance; a fact also demonstrated by the controlled release studies. The presence of bioactive principles, as well as tannins and lipoic acid, gives biomaterials an antioxidant capacity on average 40%–50% higher compared to the base matrix. The results of the tests of the mechanical resistance, mucoadhesiveness, bioadhesiveness, water absorption and antioxidant capacity of active principles recommend these biomaterials for the manufacture of cosmetic masks or patches.