Methacrylate-containing polymers hydrolysis

The physical properties of the acid- and ion-containing polymers are quite interesting. The storage moduli vs. temperature behavior (Figure 8) was determined by dynamic mechanical thermal analysis (DMTA) for the PS-PIBMA diblock precursor, the polystyrene diblock ionomer and the poly(styrene)-b-poly(isobutyl methacrylate-co-methacrylic acid) diblock. The last two samples were obtained by the KC>2 hydrolysis approach. It is important to note that these three curves are offset for clarity, i.e. the modulus of the precursor is not necessarily higher than the ionomer. In particular, one should note the same Tg of the polystyrene block before and after ionomer formation, and the extension of the rubbery plateau past 200°C. In contrast, flow occurred in... 

Open-cell PolyHIPE materials have also been prepared from hydrophilic methacrylates which, on hydrolysis, yield hydrophilic polymethacrylic acid-based species [155]. Stable HIPEs containing high levels of glycidyl methacrylate can also be formed, from which porous polymers can be made. These have considerable potential for further exploitation due to the reactive epoxide group [156],... 

Chemical Properties. The chemical-resistance properties of methacrylic ester polymers are even higher than those of the acrylic esters. Methacrylic esters imdergo a lower degree of hydrolysis in either acidic or alkaline media than acrylics. Both acrylics and methacrylics easily outperform vinyl acetate-containing polymers which are well known to be susceptible to hydrolysis of the side-chain ester. There are marked differences in the chemical-resistance properties of different forms of PMMA. The syndiotactic (alternating) form of PMMA is the most chemically inert. The rate of hydrolysis for syndiotactic PMMA is lower than that for isotactic (26) radical polymerizations generate large portions of syndiotactic PMMA and benefit in terms of stability. 

Supemucleophilic polymers containing the 4-(pyrro-lidino)pyridine group were synthesized from the corresponding maleic anhydride copolymers and also by cyclopolymerization of N-4-pyridyl bis(methacryl-imide). The resulting polymers were examined for their kinetics of quaternization with benzyl chloride and hydrolysis of pj-nitrophenylacetate. In both instances, the polymer bound 4-(dialkylamino)pyridine was found to be a superior catalyst than the corresponding low molecular weight analog. 

Levulinic acid is obtained by hydrolysis of cellulose-containing biomass. R D is actively conducted at DuPont Co. to employ levulinic acid for the synthesis of pyr-rolidones (solvents and surfactants), a-methylene-y-valerolactone [monomer for the preparation of polymers similar to poly(methyl methacrylate)], and levulinic acid esters (fuel additives) [26]. 

Copolymers of ethylene (E) or propylene (P) with acrylic acid (AA) or methacrylic acid (MA) were obtained from SP2 (USA) and used as received (EAA, PAA, PEAA, PMA). Copolymers of ethylene and vinyl alcohol (EVOH) were prepared by hydrolysis (NaOH 0,5M in methanol, reflux, 48 h), of commercial ethylene-vinyl acetate copolymers (EVA, Elf-Atochem) containing 5, 9, 14, and 18 w% of acetate. Hydroperoxides of EPDM based on 5-ethylidene-2-norbornene (0.7 mol Kg 1, Exxon) and polyoctenamer (Vestenamer, VEST, Hiils) resulted from a reaction of polymer films with singlet oxygen. 

After drying this block polymer precursor, partial hydrolysis of the methacrylate block lead to the ion containing block copolymer. The hydrolysis route is shown in Scheme II. The hydrolysis method employed utilized potassium superoxide as a general route to ester cleavage to generate in a direct fashion potassium carboxylate units. 

---