Abstracts Book - IMRC 2018

• SB2-O008
EFFECT OF PH-SENSITIVE POLYMERS ON THE LCST OF SR-g-NVCL
SYNTHESIZED BY GRAFTING-RADIATION METHOD
Victor Hugo Pino Ramos 1 , Gerardo Cedillo 2 , Emilio Bucio 3
1 Instituto de Ciencias Nucleares UNAM, Polymers, Mexico. 2 Instituto de Ciencias Nucleares
UNAM, Chemistry, Mexico. 3 Instituto de Ciencias Nucleares UNAM, Chemistry radiation,
Mexico.
Polymer surface modification has emerged as an important alternative to
synthesize of new polymeric biomaterials with potential applications in
biomedicine. Some of most important objectives of surface modification are the
enhancement of biocompatibility of implantable devices and their possible use
as drug carriers. Thermo and pH-sensitive polymers are a class of materials that
have attracted a lot of attention due to the present swelling-deswelling process
at changes in temperature and/or pH of their environment, respectively. Ionizing
radiation represents a very interesting tool to carry out polymer surface
modification without use any catalyst. In this work we synthesized different
binary graft copolymers with thermo and pH-sensitive properties by means of
grafting-radiation technique in two steps. Monomer concentration and applied
dose effects were studied on the grafting yield. The grafted films were
characterized by FTIR-ATR, thermogravimetrical analysis (TGA), 13 C-CPMAS NMR.
The hydrophilic improvement of modified films was analyzed by changes of
swelling degree in aqueous media and water contact angle. Effects of acrylic acid
(AAC), 4-vinylpyridine (4VP), and N-vinylimidazole (NVIM) on the lower critical
solution temperature (LCST) of N-vinylcaprolactam (NVCL) onto SR (SR-g-NVCL)
were analyzed. A reversal behavior was observed when pH-sensitive polymer
content was slightly higher to poly(NVCL) content on the grafted film, this
phenomenon is very interesting and is rarely reported in literature.
Acknowledgment:
This work was supported by DGAPA-UNAM under Grant IN201617. The authors
thank B. Leal and M Cruz ICN-UNAM for their technical assistance.
Keywords: Grafting-radiation, LCST, Surface-modification
Presenting authors email: victor.pino@correo.nucleares.unam.mx