Polyacrylate in pressure sensitive adhesive can be composed of a wide range of monomers in a variety of ways

Polyacrylate can be composed of a large selection of monomers in a variety of ways. In this way, the pressure-sensitive adhesives of the polymers and their affinity to the surfaces to be bonded, such as human skin, can be adjusted within a wide range of limits.

In this respect, the chemical nature of the side chain on the cool stem of polyacrylic acid plays a key role. The side chain not only determines the hydrophilic-lipophilic balance in the polymer, for example, the amount of moisture that can be absorbed; In particular, the use of appropriate side chains and their mixtures can be used to reduce the crystallinity of polymers. The decrease in crystallinity and solidification of the glass transition temperature has a positive effect on the pressure-sensitive adhesion properties of the polymer, which promotes fluidity and the resulting rapid surface wetting.

The low glass transition temperature is of particular importance for the medical applications of TTSs: in the amorphous state, the polymer, i.e., its side chain pharmaceutical active substance and containing an adjuvant, is particularly permeable. This is necessary for rapid release at the site of the application.

Polyacrylates are highly soluble for most pharmaceutical active substances. In general, the solubility is higher than in other pressure-sensitive adhesives suitable for the manufacture of TTSs, such as in natural rubber-resin mixtures, or in pressure-sensitive siloxane adhesives.

Often, the required amount of the active substance is in fact only soluble in – and therefore mixed into – the TTS in a form most suitable for delivery. – Polyacrylate is used within the polyacrylate to polymerize acetate acrylic acid – or methacrylic acid into polyacrylic acid, the latter of which may have a free antelope group on its chain. The basis is suitable for later connecting several polymer chains to each other through the basis. Typical agents known to skilled persons in the field are organometallic complexes such as ethyl acetone aluminum or ethyl acetone complex. It can introduce polyvalent cations into the polymer, which can simultaneously bind to several antelope groups on different polymer chains.