Synthesis and functionalities of poly (N‐vinylalkylamide). IV. Synthesis and free radical polymerization of N‐vinylisobutyramide and thermosensitive properties of the polymer

Abstract

Pyrolysis of ( N-a-isopropoxyethyl)isobutyramide, which was obtained by the reaction of isobutyramide, 2-propanol, and acetaldehyde in the presence of conc. sulfuric acid, produced N-vinylisobutyramide (NVIBA). The free radical polymerization of NVIBA was carried out in various solvents in the presence of a radical initiator. It was found that the polymerizability of NVIBA is similar to that of N-vinylacetamide. The resulting polyNVIBA showed a lower critical solution temperature (LCST) sharply at 39ЊC. Thermosensitive properties of polyNVIBA were investigated in comparison with poly(N-isopropylacrylamide).

Thermogelation of amphiphilic poly(asparagine) derivatives

“…Poly( N ‐isopropylacrylamide) (PNIPAAm) is known as one of the representative thermoresponsive polymers, and its aqueous solution shows a reversible and rapid LCST‐type phase separation around body temperature (32°C) due to the hydration–dehydration change in the polymer chain 21–23. Besides PNIPAAm and its copolymers, poly(vinyl ether)s,24, 25 poly(2‐isopropyl‐2‐oxazoline),26 poly( N ‐vinylalkylamide)s,27 and poly (phosphazene)s28 were developed as thermoresponsive polymers. However, lack of biodegradability and biocompatibility restricts their potential applications in biomedical fields.…”

Synthesis and Thermosensitive Properties of Poly[(N‐vinylamide)‐co‐(vinyl acetate)]s and Their Hydrogels

“…[17][18][19][20][21][22][23][24][25][26] The monomers have the opposite amide structure of the acrylamide Full Paper: Free radical copolymerization of water-soluble N-vinylamides such as N-vinylacetamide (NVA) and N-vinylformamide (NVF) with hydrophobic vinyl acetate (VAc) gave amphiphilic copolymers. The monomer reactivity ratios were determined as r 1 ¼ 5.8 and r 2 ¼ 0.68 (M 1 ¼ NVA, M 2 ¼ VAc) and r 1 ¼ 6.2 and r 2 ¼ 0.37 (M 1 ¼ NVF, M 2 ¼ VAc), respectively.…”

“…[19] In particular, aqueous solutions of poly(N-vinylisobutyroamide) (poly(NVIBA)), which have the same chemical composition as poly-(NIPAAm) but with the reversed amide linkage, showed a LCST around 39 8C, which was significantly higher than that of poly(NIPAAm). [18] We have previously prepared copolymers of NVF and N-vinylisobutyroamide (NVIBA), and analyzed their thermosensitive properties. [27] The LCST increased with an increasing the hydrophilic component of NVF in the copolymer.…”

Dendrimer-based bionanomaterials produced by surface modification, assembly and hybrid formation

“…Because the isobutyramide (IBAM) group is the side group of poly(N-vinyl isobutyramide), which is a thermosensitive polymer with a LCST of ca. 39 1C, 41 we incorporated the IBAM group into every chain end of the PAMAM dendrimers. As presented in Figure 4, the IBAM-terminated PAMAM G2 dendrimer was soluble in water in the experimental temperature region, but those of higher generations exhibited a cloud point at a specific temperature, which is indicative of the LCST.…”