resumo
Novel nanostnictured composite materials based on bacterial cellulose membranes (BC) and acrylate polymers were prepared by in situ atom transfer radical polymerization (ATRP). BC membranes were fiinctionalized with initiating sites, by reaction with 2-bromoisobutyryl bromide (BiBBr), followed by atom transfer radical polymerization of methyl methacrylate (MIV1A) and n-butyl acrylate (BA), catalyzed by copper(I) bromide and N,/N,N',N",N"-pentamethyldiethylenetriamine (PMDETA), using two distinct initiator amounts and monomer feeds. The living characteristic of the system was proven by the growth of PBA block from the BC-g-PMMA membrane. The BC nanofiber sleeving was clearly demonstrated by SEM imaging, and its extent can be tuned by controlling the amount of initiating sites and the monomer feed. The ensuing nanocomposites showed high hydrophobicity (contact angles with water up to 134), good thermal stability (initial degradation temperature in the range 241-275 degrees C), and were more flexible that the unmodified BC membranes.
palavras-chave
TRANSFER RADICAL POLYMERIZATION; SOLID-STATE C-13; POLY(METHYL METHACRYLATE); BIOMEDICAL APPLICATIONS; MICROBIAL CELLULOSE; BLOCK-COPOLYMERS; SURFACE; MEMBRANES; LIDOCAINE; DIFFUSION
categoria
Biochemistry & Molecular Biology; Chemistry; Polymer Science
autores
Lacerda, PSS; Barros-Timmons, AMMV; Freire, CSR; Silvestre, AJD; Neto, CP
nossos autores
Ana Margarida Madeira Viegas de Barros Timmons
Professor associado
Armando Jorge Domingues Silvestre
Professor Catedrático
Carlos Pascoal Neto
Diretor do Raiz
Carmen Sofia da Rocha Freire Barros
Investigador Coordenador
Paula Sofia Sarrico Lacerda
InvestigadorProjectos
agradecimentos
Paula Lacerda would like to thank CICECO for the awarding of a research grant. CICECO acknowledges FCT for Pest-C/CTM/LA0011/2011 project. Thermal Analysis Laboratory was funded by FEDER Funds through Programa Operacional Factores de Competitividade - COMPETE and by National Funds through FCT under Project REEQ/515/CTM/2005. Dr Dmitry Evtyugin is acknowledged for the GCP Analysis.