Abstract
This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of silicone rubber (SR) substrates grafted with N-vinylcaprolactam (NVCL) and N-vinylimidazole (NVIM), modified by the simultaneously polymerization and grafting method, which is expected to result in valuable new applications in the near future. The modification of silicone rubber was carried out via γ-ray radiation in order to graft a binary copolymer, poly(N-vinylimidazole-co-N-vinylcaprolactam), by the pre-irradiation method, to obtain pH- and thermo-responsive materials. The grafting yield was found to be directly proportional to the dose and monomers concentration. The biomaterials were characterized by using Fourier-transform infrared attenuated total reflection (FTIR-ATR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and swelling; and their stimuli behavior was evaluated by lower critical solution temperature (LCST) and pH critical studies.
Highlights
Γ-rays generate free radicals on the monomers (NVIM and NVCL) and silicone rubber (SR); the radicals generated on the SR initiate the grafting process by reacting with the vinyl substituent of the monomers
It can be gathered that a higher monomer concentration favors “the gel effect” and crosslinking, which results in a slower termination step due to the lack of mobility of the growing chains
Stimuli responsive systems still remain the subject of vigorous research, which is expected to result in valuable new applications in the near future
Summary
The technological and scientific advance of humanity is linked to the evolution of materials, there are different kinds of materials such as ceramics, polymers and composites [1], those that are used for the development of medical devices have been traditionally called biomaterials [2].There are many definitions of biomaterials, any current definition of biomaterials is neither perfect nor complete, such as “any substance or combination of substances, other than drugs, synthetic or natural, which augments or replaces partially or totally any tissue, organ or function of the body, in order to maintain or improve the quality of life of the individual” [3,4] or any non-drug material that can be used to treat, enhance or replace any tissue, organ or function in an organism [5]; the term biomaterials includes materials derived from biological sources [6].Almost from the birth of the field of polymer science, polymers have been widely used in medicine [6]because of their chemical versatility and biocompatibility [7]. There are several factors that should be considered before using a polymer for biomedical applications, such as its chemical composition, physical characteristics [8], molecular weight, solubility, shape, structure, hydrophilicity/hydrophobicity [7], and biocompatibility This last one, biocompatibility, “is very important for the development of biomaterials and is described as the ability of a material to perform with an appropriate host response a specific function” [8]. Are made using synthetic polymers like poly(methyl methacrylate), polypropylene, poly(vinyl chloride), polyethylene, and silicone rubber (SR) [8] Solid surfaces, including those made out of synthetic polymers, are susceptible to the bacterial adhesion [1,9] phenomenon, which can lead to undesirable effects like hospital-acquired infections (HAIs). The most frequent pathogens causing HAIs are the Coagulase Negative Staphylococci (CoNS) genus [9,11], Staphylococcus epidermis [12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
