Dual cure compositions employing free radical and RTV cure

1. A composition of matter comprising the structure:

wherein A is a polyether or polyester polyol backbone, comprising the structure:

Wherein R is H or

which may be further substituted by R to extend the polyol backbone up to six total alcohol groups per each polymeric structure, and

where R 2′ is:

(i) an alkylene (meth)acrylate terminated urethane containing linkage; or

(ii) an alkylenealkoxysilyl terminated linkage;

where R 3 , R 7 and R 11 may be the same or different and are each H or C 1-6 alkyl; R 4 , R 8 and R 12 may be the same or different and are each alkylene C 1-6 , W is free valency or

 x is 1 to 40, q is 0.1 to 1, s is 0.1 to 1, and t is 0.1 to 1, where q, s and t together are no more than 3;

R 1 is a carbamoyl containing linkage or a hydrocarbon diradical joined to A through a carbamoyl linkage; and

R 2 is a member selected from the group consisting of:

(A) (i) an alkylene (meth)acrylate terminated urethane containing linkage; and

(ii) an alkylene alkoxysilyl terminated linkage; or

(iii) an alkylene alkoxysilyl terminated urea containing linkage,

provided that greater than one of group (i) and at least one of group (ii) or (iii) are present;

or

(B) (i) a photocurable portion comprising a urethane or carbamate linkage terminated with a (meth)acryloxyalkyl group;

(ii) a moisture curable portion terminated with a polyalkoxysilyl group; and

(iii) a moisture curable portion comprising a urea linkage terminated with an alkylpolyalkoxysilyl group, provided that there are present: (a) at least two photocuring portions and at least one moisture curing portion; or (b) at least two moisture curing portions from the same group and at least one photocuring portion, and n is >2 up to 6.

2. The composition of claim 1 , further comprising a photoinitiator.

3. The composition of claim 1 , further comprising a moisture cure catalyst.

4. The composition of claim 1 , further comprising a hydroquinone stabilizer.

5. The composition of claim 1 , wherein said polyol is a polypropyleneoxide polyol.

6. The composition of claim 1 , wherein said photocurable portion comprising a urethane or carbamate linkage terminated with a (meth)acryloxyalkyl group is formed by reacting a diisocyanate with an hydroxyalkyl (meth)acrylate in amounts sufficient for retaining isocyanate functionality.

7. The composition of claim 6 , wherein the diisocyanate is isophorone diisocyanate.

8. The composition of claim 6 , wherein the hydroxyalkyl (meth)acrylate is hydroxyethyl acrylate.

9. A composition of matter comprising the structure:

wherein R 3 , R 7 and R 11 may be the same or different and are each H or C 1-6 alkyl;

R 4 , R 8 and R 12 may be the same or different and are each alkylene C 1-6 ;

R is H or

which may be further substituted by R to extend the polyol backbone up to six total alcohol groups per each polymeric structure, and

wherein R 2′ is a member selected from the group consisting of:

(i) an alkylene (meth)acrylate terminated urethane containing linkage; or

(ii) an alkylenealkoxysilyl terminated linkage

(iii) an alkyene (meth)acrylate terminated methane containing linkage; and

(iv) an alkylenealkoxysilyl terminated urea containing linkage;

W is a free valency or

x is 1-40;

Z is:

R 5 and R 9 may be the same or different and are C 2-20 substituted or unsubstituted divalent organic radicals;

R 6 and R 10 are each (meth)acryloxyalkyl groups;

Y 1 is: NH—R 13 or

wherein R 13 is:

m=0 or 1;

R 14 and R 15 are C 1 -C 3 alkyl; and

R 17 is a C 1-13 alkylpolyalkoxysilyl group; and

R 18 is a C 1-10 alkyl or cycloalkyl group.

10. A method of forming a gasket assembly, comprising the steps of:

(a) applying the composition of claim 1 to at least one of two substrate surfaces;

(b) exposing the composition to moisture and/or photoradiation to effectuate at least partial cure; and

(c) mating the substrate surfaces in abutting relationship to form the gasket assembly.

11. A method for using the composition of claim 1 to seal together two substrates, comprising the steps of:

(a) applying the composition to at least one of two substrate surfaces;

(b) mating the substrate surfaces in abutting relationship to form an assembly;

(c) exposing the composition to moisture and/or photoradiation; and

(d) maintaining the abutting relationship for a time sufficient to allow the composition to cure.