Styrene-free unsaturated polyester
View Patent ↗A thermosetting unsaturated polyester resin (UPR) composition comprising an unsaturated polyester polymer having at least two strained cycloolefinic double bonds and optional unstrained cycloolefinic double bonds, which can be cross-linked through a ring-opening metathesis polymerization (ROMP) or combination of ROMP and cationic or free radical polymerization is provided. No styrene is used in the resin composition. The thermosetting unsaturated polyester resin composition also comprises a catalyst system for the ring-opening metathesis polymerization, and in embodiments, can further comprise one or more optional unsubstituted or substituted cycloolefin monomer containing unsaturation, an optional co-catalyst selected from a cationic initiator or free radical initiator, and optional additives. The cured resin properties can be controlled through adjusting the structure and properties of the unsaturated polyester resin.
1. A polymerizable thermosetting unsaturated polyester resin composition containing no styrene monomer, comprising:
a) an unsaturated polyester polymer containing at least two strained cycloolefinic double bonds, which can be cross-linked through a ring-opening metathesis polymerization (ROMP); and
b) a catalyst system for the ring-opening metathesis polymerization;
wherein the unsaturated polyester polymer containing at least two strained cycloolefinic double bonds is the reaction product of a norbornene compound containing functional groups or linkages selected from the group consisting of alcohol, carboxylic acid, ester and anhydride, with a glycol or polyhydric alcohol, and a di- or polycarboxylic acid or anhydride, and
has a weight average molecular weight of at least about 1000 and a polydispersity greater than or equal to about 2.
2. The resin composition of claim 1 , wherein the unsaturated polyester polymer containing at least two strained cycloolefinic double bonds contains non-cycloolefinic carbon-carbon double bonds.
3. The resin composition of claim 1 , wherein the unsaturated polyester polymer contains unstrained cycloolefinic double bonds.
4. The resin composition of claim 1 , wherein the unsaturated polyester polymer can be cross-linked through a combination of ROMP and a cationic or free radical polymerization.
5. The resin composition of claim 1 , further comprising an unsubstituted or substituted cycloolefin monomer containing unsaturation to reduce viscosity of the resin composition.
6. The resin composition of claim 5 , wherein the unsubstituted or substituted cycloolefin monomer is selected from the group of a monocyclic olefin, a bicyclic olefin, a polycyclic olefin, a heterocyclic olefin, and mixtures thereof.
7. The resin composition of claim 1 , wherein the ring-opening metathesis polymerization catalyst system is selected from the group consisting of a one-component ROMP catalyst, a two-component ROMP catalyst, or a multi-component ROMP catalyst.
8. The resin composition of claim 1 , further comprising a co-catalyst selected from the group consisting of a cationic initiator and a free radical initiator.
9. The resin composition of claim 8 , wherein the co-catalyst is a free radical initiator comprising a peroxide selected from the group consisting of t-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, and mixtures thereof.
10. The resin composition of claim 8 , wherein the co-catalyst is a cationic initiator comprising a one-component Lewis acid catalyst, or a two-component Lewis acid catalyst.
11. The resin composition of claim 1 , further comprising one or more additives selected from the group consisting of fibers, fillers, reinforcing agents, wetting agents, leveling aids, viscosity modifiers and pigments.
12. The resin composition of claim 1 , wherein the resin composition is curable at a temperature range of about 20-200° C.