Water-soluble copolymer composition with neutral pH
The present invention relates to the field of copolymers which are water-soluble or water-dispersible at neutral pH or near-neutral pH, that is to say between 5.5 and 9.5, comprising at least one random copolymer comprising methacrylic acid, butyl acrylate, styrene and a monomer chosen from styrenesulfonic acid or salts thereof, vinylbenzoic acid or salts thereof, 2-acrylamido-2-methanesulfonic acid or salts thereof, N-vinylpyrrolidone, alone or in combination.
1. A composition comprising a random copolymer, where the random copolymer comprises the following monomers:
1 to 45% by weight of styrene, limits included;
35 to 45% by weight of methacrylic acid, limits included;
15 to 35% by weight of butyl acrylate, limits included;
1 to 45% of a monomer chosen from styrenesulfonic acid or salts thereof, vinylbenzoic acid or salts thereof, 2-acrylamido-2-methanesulfonic acid or salts thereof, N-vinylpyrrolidone, alone or in combination, limits included,
wherein the weight % is relative to the total weight of the random copolymer, and
wherein the random copolymer has a weight-average molecular weight of between 30,000 and 300,000 g/mol.
2. The composition as claimed in claim 1 , wherein the random copolymer is prepared by controlled radical polymerization.
3. The composition as claimed in claim 1 , wherein the glass transition temperature of the copolymer as measured by DMA is greater than 60° C.
4. The composition as claimed in claim 2 , wherein the polymerization is carried out by RAFT controlled radical polymerization.
5. The composition as claimed in claim 2 , wherein the polymerization is carried out by ATRP controlled radical polymerization.
6. The composition as claimed in claim 1 , wherein the polymerization is carried out by NMP controlled radical polymerization.
7. The composition as claimed in claim 6 , wherein the nitroxide from the NMP is from alkoxyamines derived from the stable radical of formula (1):
wherein R L has a molar mass of greater than 15.0342 g/mol.
8. The composition as claimed in claim 7 , wherein the alkoxyamines are derived from the following stable radicals:
N-(tert-butyl)-1-phenyl-2-methylpropyl nitroxide,
N-(tert-butyl)-1-(2-naphthyl)-2-methylpropyl nitroxide,
N-(tert-butyl)-1-dibenzylphosphono-2,2-dimethylpropyl nitroxide,
N-phenyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide,
N-phenyl-1-diethylphosphono-1-methylethyl nitroxide,
N-(1-phenyl-2-methylpropyl)-1-diethylphosphono-1-methylethyl nitroxide,
4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy,
2,4,6-tri-tert-butylphenoxy nitroxide,
N-(tert-butyl)-1-diethylphosphono-2,2-dimethylpropyl nitroxide.
9. The composition as claimed in claim 8 , wherein the alkoxyamines are derived from N-(tert-butyl)-1-diethylphosphono-2,2-dimethylpropyl nitroxide.
10. A filament extruded from a composition as claimed in claim 1 .