Graft copolymers prepared by ethoxylation of polyamide 12 and poly(ethylene-co-vinyl alcohol)

Synthesis and characterization of poly(ethylene-vinyl alcohol)-g-poly(butyl acrylate) copolymers

“…EVOH copolymer has hydroxyl groups on the chain and there are examples of modification of EVOH by conventional esterification to produce a polyethylene chain backbone with attached carboxyl groups [8], phthalate derivatives [9] stearic acid side chains [11], methyl methacrylate [12,13], succinic anhydride groups [14], ethylene oxide [15], lactic acid [16] and caprolactone [17][18][19].…”

Controlled Anionic Graft Polymerization of Ethylene Oxide Directly from Poly(N-isopropylacrylamide)

“…For a better modulation of the properties of PEO-based graft copolymers, synthetic methodologies have been developed for controlling molecular weight, composition, side chain length, and distribution. ,− Nevertheless, the preparation of PNIPAM- g -PEO has achieved quite limited development. To our knowledge, two conventional methods have been involved so far, namely, the coupling of end-functionalized PEO onto PNIPAM with reactive moieties (“grafting onto”) , and the copolymerization of NIPAM with PEO macromonomer (“grafting through”). , However, from a chemical point of view, neither of these two methods can achieve absolutely random distribution of PEO chains along the backbone.…”

“…The graft polymerization of ethylene oxide (EO) from backbones with multifunctional initiating sites has been employed quite often. − Such a “grafting from” technique is able to achieve a better control of the synthesis and a wide variety of molecular characteristics compared to the other two techniques mentioned above. The main disadvantages are the use of metal-based catalysts as well as the necessity of incorporating functional moieties into the backbone polymer, − which inevitably inflicts complexity on the synthetic procedures and doubt about the randomness of the side chain distribution.…”

“…It is known that amide moieties in the backbone polymer can be deprotonated by a strong base, thus generating anionic initiating sites to polymerize EO. , In our previous work, the phosphazene base, t -BuP 4 , has opened a new pathway to PEO-based linear and graft copolymers via metal-free anionic polymerization. , Therefore, we were inspired to take advantage of both t -BuP 4 and secondary amide moieties in PNIPAM, so as to create anionic initiating sites and grow PEO directly from PNIPAM backbone (Scheme ). By this approach, the synthesis of PNIPAM- g -PEO would be greatly simplified since the introduction of functional moieties is avoided.…”

“…The PNIPAM solution turned yellowish immediately upon addition of t -BuP 4 , indicating the occurrence of deprotonation and the generation of anions. The deprotonation of primary and secondary amide moieties in a polymer backbone by potassium tert- butoxide was proven to be effective. , Considering the much higher basicity, we expected that the deprotonation of NIPAM units with t -BuP 4 would be quantitative.…”