Water insoluble hydroxyethyl methacrylate hydrogels - with low diester content, are soluble in methanol and useful e.g. as burn dressings

摘要

Solid water-insoluble, methanol-soluble, hydrophilic polymers are made by polymerising a monomer HO-R-O-CO-C(R')=CH2 (I) (where R is2-3C alkylene group and R' is H or Me), in the presence of water with is not 0.035 wt. % (on wt. of monomers) of a diester of formula: H2C=C(R')-CO-O-R-O-CO-C(R')=CH2 (II). Pref. monomer (I)is 2-hydroxyethylmethacrylate (III) and the diester (II) is ethyleneglycoldimethacrylate (IV). Polymerisation is carried out e.g. using a free radical initiator and with a ratio of (III) to water of 10:90 to 70:30, esp. about 35:65 to give a polymer with a mol. wt. of about 250,000. The polymers are porous in nature and can easily be washed to a high degree of purity. They are insoluble in water but dissolve in solvents such as (m)ethanol, isopropanol, ethylene glycol, diethylene glycol, etc. The purified polymers are esp. useful for medical applications such as carriers or encapsulating agents for germicides, fungicides, antibiotics, analgesics, etc. In micropulverised form, the polymers are useful in the prepn. of burn dressings.