Amphiphilic polymethacrylates as crosslinked polymer precursors obtained by free-radical monomethacrylate/dimethacrylate copolymerizations

Novel amphiphilic network polymers consisting of nonpolar, short primary polymer chains and polar, long crosslink units: Influence of characteristic dangling chains on swelling behavior of resulting amphiphilic gels

“…The reasonable conditions were evaluated by the comparison of the actual gel point with the theoretical one and by examining the swelling ratios of resulting gels as follows 13. Thus, the copolymerization of BzMA with 5 mol % (corresponding to 27.5 wt %) of PEGDMA‐23 was carried out in 1,4‐dioxane at a dilution of 2/3 with 0.04 mol/L of AIBN at 50 °C in the presence of different amounts of LM ([LM]/[total monomer] = 1/200, 1/50, and 1/20).…”

“…As described in the Introduction, the incorporation of rather rigid or flexible dangling chains into the network polymer was designed either by shortening the primary polymer chain length or by the copolymerization with MPEGMA‐23, respectively. The former was done by changing the added amounts of the chain‐transfer agent, LM ([LM]/[total monomer] = 1/200, 1/50, and 1/20), to provide the amphiphilic network polymer with different primary polymer chain lengths, that is, P w,0 values of 617, 238, and 125, respectively 13…”

“…In our previous research,12, 13 the preparation of novel amphiphilic polymers as crosslinked polymer precursors, different from the preceding types of amphiphilic polymers, was reported as an extension of our work on the elucidation of the mechanism and control of three‐dimensional network formation in the free‐radical crosslinking polymerization and copolymerization of multi‐vinyl compounds with the aim to molecularly design vinyl‐type network polymers;14 that is, the free‐radical crosslinking copolymerization of benzyl methacrylate (BzMA) with tricosaethylene glycol dimethacrylate [CH 2 C(CH 3 )CO(OCH 2 CH 2 ) 23 OCOC(CH 3 )CH 2 , PEGDMA‐23] in the presence of lauryl mercaptan (LM) as a chain‐transfer agent was investigated. Because BzMA forms rather rigid, nonpolar primary polymer chains and PEGDMA‐23 as a crosslinker contains a flexible, polar poly(oxyethylene) unit, the resulting prepolymers as vinyl‐type network‐polymer precursors would provide novel amphiphilic polymers.…”

“…The viscosities in the t ‐BB/MeOH (80/20) mixture were quite high as compared with those in t ‐BB, and completely reversed concentration dependencies were observed in the solvents. These have been discussed by considering the difference in conformation and the shrinkage of polar, flexible poly(oxyethylene) units or the entanglement of nonpolar, rigid primary polymer chains 13…”

The influence of intramolecular cyclization and intermolecular crosslinking on the properties of polymeric networks obtained in the radical polymerization of multifuctional methacrylates

“…W procesie formowania sieci polimerowej, w rodnikowej homo-i kopolimeryzacji monomerów multiwinylowych, mo¿na wyodrêbniae cztery zasadnicze typy reakcji: miêdzycz¹steczkow¹ propagacjê monomerów o ró¿nej funkcyjnooeci, wewn¹trzcz¹steczkow¹ cyklizacjê (pierwotn¹ i wtórn¹) prowadz¹c¹ do powstania struktur o charakterze pêtli, miêdzycz¹steczkowe sieciowanie z prepolimerem oraz wewn¹trzcz¹steczkowe sieciowa-nie w obrêbie prepolimeru [6]. W wyniku sieciowania powstaje trójwymiarowa struktura o wymiarach makroskopowych, formuj¹ siê tak¿e liczne rozga³êzienia w sieci polimerowej.…”