Libraries of methacrylic acid and oligo(ethylene glycol) methacrylate copolymers with LCST behavior

Abstract

Homopolymers of methacrylic acid (MAA), monoethyleneglycol methyl ether methacrylate (MEOMA), diethyleneglycol methyl ether methacrylate (MEO 2 MA), oligo(ethyleneglycol) methyl ether methacrylate (OEGMA 475 and OEGMA 1100) and oligo(ethyleneglycol) ethyl ether methacrylate (OEGEMA 246) were synthesized with various chain lengths via reversible addition fragmentation chain transfer (RAFT) polymerization. The homopolymers of MAA, MEOMA and OEGMA 1100 did not show any cloud point (CP) in the range of 0-100 C, whereas at a pH value of 7, the CPs were found to be 20.6, 93.7, and 20.0 C for p(MEO 2 MA), p(OEGMA 475) and p(OEGEMA 246), respectively, with an initial monomer to initiator ratio of 50. Furthermore, statistical copolymer libraries of MAA with OEGMA 475 and OEGMA 1100 were prepared. The cloud points of the random copolymers of MAA and OEGMA 475 were found to be in the range of 20-90 C; surprisingly, even though the homopolymers of MAA and OEGMA 1100 did not exhibit any LCST behavior, the copolymers of these monomers at certain molar ratios (up to 40% OEGMA 1100) revealed a double responsive behavior for both temperature and pH. Finally, the cloud points were found to be in the range of 22-98 C, measured at pH values of 2, 4, and 7, while no cloud point was detected at pH 10. V

Living Radical Polymerization by the RAFT Process - A Second Update

“…For an efficient RAFT polymerization (Scheme 1, Fig. 3 22* [86] S S MA [54] AAEMA [87] MAEP [87] MMA [88,89] AEMA [90] DMAEMA [91] (TPMMA) [92] TFPMA [93] St [48,94,95] 277 [96] 278 [96] 392 [97,98] 345 [99] 348 [100] 347 [101] St [51] 364 [102] 365 [102] NVP [103] 385 [104] 386 [98] 387 [104] 388 [104] 389 [104] 390 [104] BA/ 407 [105] St/MAH [53] AAEMA-b-AEP [87] AAEMA-b-MAEP [87] MAEP-b-AAEMA [87] BMA/TMSEMA [106] TFPMA-b-tBA [93] St-b-NIPAM [95] St-b-HEMA/DMAEMA [86] 364-b-384 [102] 365-b-384 [102] 386-b-392 [97] 23* [107] S CN S DEGMA [108] EGMA [108] MAA [108] MMA [109] PEGMA …”

“…[114,115,251] High throughput methods have been applied to synthesize libraries of methacrylate polymers (MAA, various oligo(ethylene glycol) methacrylates and copolymers of MAA with PEGMA, [108] MMA, DMAEMA and block and statistical copolymers, [114] and copolymers of DMAEMA with PEGMA [113] ) for evaluating the composition dependence of the lower critical solution temperature (LCST).…”

Thermoresponsive Polymers for Biomedical Applications

“…Adjustment of the LCST of PNIPAAm has been achieved by copolymerizing with hydrophilic or hydrophobic monomers rendering the overall hydrophilicity of the polymer higher or lower respectively [3,5,6,15]. Other polymers with thermoresponsive properties include poly(N,N-diethylacrylamide) (PDEAAm) with an LCST over the range of 25 to 32 °C, poly(N-vinlycaprolactam) (PVCL) [7,8,16] with an LCST between 25 and 35 °C, poly [2-(dimethylamino)ethyl methacrylate] (PDMAEMA) [17][18][19][20][21][22] with an LCST of around 50 °C [21] and poly(ethylene glycol) (PEG), also called poly(ethylene oxide) (PEO) whose LCST is around 85 °C [23][24][25][26]. It should be noted the LCST is affected by the size of the side groups.…”

Enzymatically Triggered, Isothermally Responsive Polymers: Reprogramming Poly(oligoethylene glycols) To Respond to Phosphatase

“…It is known to have similar reactivity ratios to HEMA ensuring random co-polymers are obtained and it has a cloud point of around 26 °C in aqueous solution. 63,64 We therefore reasoned that addition of Phos-HEMA units would raise the cloud point, but upon enzymatic cleavage, reduce it, such that an isothermal transition at 37 °C could be obtained. To assess the effect of Phos-HEMA on the cloud point of the DEGMA-based co-polymers, a series of copolymers was prepared (Table 2).…”