Novel biocompatible multiblock Polydimethylsiloxane-PA1212 copolymers

Although polyamide-co-polyether, the most important co-polyamide species, has achieved big success, the inadequate biocompatibility still restricts it further application in biomedical area. In this paper, polydimethylsiloxane (PDMS) segment is introduced into copolymer to replace polyether segment, which is intended to fulfill the copolymer with improved surface performance. Two prepolymer condensation process was used to synthesis the novel PA1212-b-PDMS series, which is constructed by PDMS flexible segment (Mn = 1000 g/mol) and PA1212 rigid segment (Mn = 1000, 3000, 5000, 7000, 10,000 g/mol). FTIR and 1H NMR were carried out to evidence the success of the copolymerization and verify the chemical structure. Melting and crystallization behavior, thermal stability, and crystal structure of the series were characterized by DSC, TG and XRD, respectively. To explore the potential usage of the copolymers, mechanical properties were thoroughly investigated. The series possess tunable toughness and rigidity corresponding to different chain compositions. When Mn of PA1212 segment is above 5000 g/mol, the copolymer presents typical tough and stiff feature with an ultimate elongation rate of around 500% and a fair tensile strength around 35 MPa. More than that, the platelet adhesion and activation test was conducted to estimate the biocompatibility of the polymers. The contact angel goniometry and XPS were further utilized to understand their surface performance. The as-prepared copolymers give distinct-different performance from homo-polyamide and polyamide-co-polyether. Barely cell adhesion on the surface indicates the greatly improved biocompatibility achieved by the series, which promises the mechanical-property-adjustable novel co-polyamide a broad prospect in biomedical area.