Enhanced mechanical and adhesive properties of PDMS based on novel PDMS-epoxy IPN structure

A high-performance interpenetrating polymer network (IPN) system was synthesized from vinyl-terminated polysiloxane (VS) and siliconized epoxy resin (ES) via one-step preparation method. The compatibility between polysiloxane and epoxy was improved due to the IPN structure, as confirmed by dynamical mechanical analysis and scanning electron microscopy. Both the mechanical and adhesive properties of modified polydimethylsiloxane (PDMS) were significantly enhanced when the weight ratio of VS: ES is 100:20 (i.e. 20p-IPN). For example, the tensile strength and elongation at break for 20p-IPN were 205% and 119.9%, which were higher than that of pure PDMS. The shear strength of 20p-IPN was also doubled when compared with that of pure PDMS counterpart. Thermogravimetric analysis showed that although the degradation temperatures were slightly reduced due to the addition of modified epoxy, the residue at 800 oC was still maintained at a very high level (56.3%) in terms of 10p-IPN. These results showed that the properties of PDMS can be markedly improved by our proposed method, which demonstrated a promising aspect for high performance engineering applications.

Automated summary

Synthesizing a high-performance interpenetrating polymer network (IPN) system from vinyl-terminated polysiloxane (VS) and siliconized epoxy resin (ES) through a one-step method significantly improves the mechanical and adhesive properties of modified polydimethylsiloxane (PDMS), especially with a weight ratio of 100:20 (i.e. 20p-IPN), showing promising potential for high performance engineering applications.