Thermal-sensitive Starch-g-PNIPAM prepared by Cu(0) catalyzed SET-LRP at molecular level

Abstract

Single electron transfer living radical polymerization (SET-LRP) was employed to prepare thermal-sensitive starch graft poly(N-isopropylacrylamide) (Starch-g-PNIPAM) with soluble Starch-Br as macro-initiator at molecular level. And Starch-g-PNIAPM with improved graft ratio and controlled length of graft chains were obtained. The effects of molar ratio of monomer to initiator and temperature on polymerization were investigated. The thermal responsibilities investigated by 1 H NMR and UV showed that the LCST ranged from 31.5 C to 23 C with the increase of the length of PNIPAM chains and the concentrations of copolymers. Starch-g-PNIPAM hydrogels were gained when adding N,N 0 -methylenebisacrylamide as crosslinking agent and the swelling and deswelling behaviors were also investigated. The obtained hydrogels possess a high equilibrium swelling ratio as high as 1826%, and an extremely rapid shrinking rate as fast as losing more than 85% of water in 5 min.

In Situ Attachment of Acrylamido Sulfonic Acid-Based Monomer in Terpolymer Hydrogel Optimized by Response Surface Methodology for Individual and/or Simultaneous Removal(s) of M(III) and Cationic Dyes

“…In the last few years, sodium salt of 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) has received attractive attention as an ionic comonomer because of the prevalent ionizable sulfonate group, which completely dissociates in the entire pH range, and thus, the hydrogels derived from AMPS exhibit pH-independent swelling and superior ion-conducting ability. Several natural polymer [STR/pectin/guar gum (GG)/gumghatti (GGTI)]-grafted hydrogels, such as STR- g -poly(acrylic acid (AA)), 22 STR- g -poly(acrylamide (AM)), 23,24 STR- g -poly( N -isopropylacrylamide (NIPA)), 25 STR- g -poly(methyl methacrylate), 26 STR- g -poly(sulfobetaine methacrylate), 27 STR- g -polystyrene, GG- g -poly(AA- co -AM), 2 STR- g -poly(acrylonitrile- co -AMPS), 28 GGTI- g -(NIPA- co -3-( N -isopropylacrylamido) sodium propanoate- co -sodium acrylate), 1 and synthetic hydrogels, such as poly(AMPS- co -itaconic acid), 29 poly(AM- co -AMPS), 30 poly(AM- co -AMPS- co -4-vinylpyridine), 31 poly(acrylamidephenylboronic acid- co -AM), 32 poly( N -dodecylacrylamide- co -AMPS), 33 and poly(AMPS- co -3-acrylamidopropyltrimethylammonium chloride), 34 have been reported for drug delivery and adsorptive exclusion of dyes and M(II/III/VI). In this context, acrylamido functionality was introduced in the matrix using several AM derivatives, such as 2-acrylamido glycolic acid, 35 AMPS, 36,37 and 3-(acrylamido) phenylboronic acid, 38 as external monomers for synthesizing copolymer hydrogels.…”

Graft modification of methyl acrylate onto chicken feather via surface initiated Cu(0)‐mediated reversible‐deactivation radical polymerization

“…Grafting different synthetic polymers onto the surface of biomaterials can ensure their hydrophobicity or hydrophilicity depending on applications. Furthermore, functional properties (e.g., stimuli‐responsivity and antibacterial properties) can also be achieved by applying a certain amount of monomers, increasing the possibility of these bioresources. In general, “Grafting to” and “Grafting from” are two major methods to prepare covalently modified surface.…”

“…It is likely to utilize products directly without difficult separation, which is a great benefit for graft copolymerization. Surface initiated Cu(0)‐mediated RDRP has been used successfully on various inorganic and organic substrates . However, Cu(0)‐mediated RDRP also have limitations in monomer and solvent selection.…”

“…Surface initiated Cu(0)-mediated RDRP has been used successfully on various inorganic and organic substrates. 10,13,[34][35][36][37][38] However, Cu(0)-mediated RDRP also have limitations in monomer and solvent selection. To be specific, less active monomers and acidic monomers are hard to process.…”

Copper-mediated homogeneous living radical polymerization of acrylamide with waxy potato starch-based macroinitiator

“…PDI around 1.5) (Jones et al, 2016;Wang, Zhong, Zhang, Magenau, & Matyjaszewski, 2012;. Few researches on the homogeneous copolymerization of starch with monomers like styrene, methyl methacrylate and N-isopropylacrylamide have been reported in recent years Wang, Wu, Men, Shen, & Liu, 2015). Although St-g-PAM has also been synthesized with ATRP, only the surface of starch granules was grafted, which limited the graft density and thus limited the performance of the final product (Najafi Moghaddam, Fareghi, Entezami, & Ghaffari Mehr, 2013).…”