Particle-based multi-network polymers

A polymerizable composition comprising:

• a. a polymer forming part comprising
• i. one or more compounds comprising a polymerizable group, and
• ii. optionally, an initiator,
• wherein a composition consisting of the polymer forming part, if 90% or more of the polymerizable groups in the polymer forming part are polymerized, has a Tg as determined by DMTA of less than 25° C. and a volume average cross-link density at 100° C. as determined by DMTA of 1.0 mol/l or less,
• b. swellable particles in an amount of 5 to 35 wt %, based on the total amount of the swellable particles and the polymer forming part in the polymerizable composition, the swellable particles comprising cross-links, being formed from a particle composition, and having
• i. a Tg of less than 25° C., as determined by DMTA by first drying the swellable particles in air until they form a film and then drying the film for 16 hours in a vacuum oven at 80° C.,
• ii. a volume average cross-link density (v) at 100° C. of 0.01 mol/l or more, as measured by DMTA on a film formed by curing the particle composition, such that 90% or more of the polymerizable groups in the particle composition are polymerized, and
• wherein the swellable particles swell to a swelling ratio of 250% or more by mass from their non-swollen state if the swellable particles are swollen to equilibrium in a mixture consisting of the polymer forming part and the swellable particles,
• c. optionally, a solvent, and
• d. optionally, a filler.

A polymerizable composition comprising

• a. a polymer forming part comprising
• i. one or more compounds comprising a polymerizable group, and
• ii. optionally, an initiator,
• wherein a composition consisting of the polymer forming part, if 90% or more of the polymerizable groups in the polymer forming part are polymerized, has a Tg as determined by DMTA of less than 25° C. and a volume average cross-link density at 100° C. as determined by DMTA of 0.2 mol/l or less,
• b. multi-network particles in an amount of from 3 to 40 wt %, based on the total amount of the multi-network particles and the polymer forming part in the polymerizable composition, the multi-network particles comprising cross-links and being formed from a process comprising the steps of:
• i. swelling a first polymer network having a volume average cross-link density (v) at 100° C. of from 0.01 to 10 mol/l as measured by DMTA, in a second network composition comprising
• 1. one or more compounds comprising a polymerizable group, and
• 2. optionally, an initiator,
• wherein a composition consisting of the second network composition, if 90% or more of the polymerizable groups in the second network composition are polymerized, has a Tg as determined by DMTA of less than 25° C. and a volume average cross-link density at 100° C. as determined by DMTA of 0.2 mol/l or less, and
• ii. polymerizing the second network composition, thereby forming a multi-network polymer,
• wherein the first polymer network swells to a swelling ratio of 50% or more by mass from its non-swollen state if the first polymer network is swollen to equilibrium in the second network composition.