Styrenic (meth)acrylic oligomers

1. A process for producing a styrenic (meth)acrylic oligomer, the process comprising:

continuously charging into a reactor a mixture comprising:

a styrenic monomer;

a (meth)acrylic monomer; and

from about 0.25 wt % to about 5 wt % of a polymerization initiator;

maintaining the mixture at a temperature from about 175° C. to about 300° C.;

separating a styrenic (meth)acrylic oligomer from the mixture; and

hydrogenating the styrenic (meth)acrylic oligomer;

wherein:

the styrenic (meth)acrylic oligomer has an insubstantial amount of olefinic unsaturation and

a residence time of the styrenic (meth)acrylic oligomer in the reactor is from about 5 minutes to about 60 minutes.

2. The process of claim 1 , wherein the hydrogenating comprises contacting the styrenic (meth)acrylic oligomer with hydrogen and a hydrogenation catalyst.

3. The process of claim 2 , wherein the hydrogenation catalyst comprises palladium or platinum.

4. The process of claim 1 , wherein the styrenic (meth)acrylic oligomer exhibits an absence of an IR absorption in the range of 1645 cm −1 to 1610 cm −1 .

5. The process of claim 1 , wherein the styrenic (meth)acrylic oligomer exhibits an absence of a resonance in the range of 4.5 ppm to 5.5 ppm in the 1 H NMR, referenced to tetramethylsilane.

6. The process of claim 1 , wherein the polymerization initiator is selected from the group consisting of an azo compound, a peroxide, and a mixture of any two or more thereof.

7. The process of claim 1 , wherein the polymerization initiator is selected from the group consisting of 2,2′-azodi-(2,4-dimethylvaleronitrile); 2,2′-azobisisobutyronitrile (AIBN); 2,2′-azobis(2-methylbutyronitrile); 1,1′-azobis(cyclohexane-1-carbonitrile); tertiary butylperbenzoate; tert-amyl peroxy 2-ethylhexyl carbonate; 1,1-bis(tert-amylperoxy)cyclohexane, tert-amylperoxy-2-ethylhexanoate, tert-amylperoxyacetate, tert-butylperoxyacetate, tert-butylperoxybenzoate, 2,5-di-(tert-butylperoxy)-2,5-dimethylhexane, di-tert-amyl peroxide (DTAP); di-tert-butylperoxide (DTBP); lauryl peroxide; dilauryl peroxide, succinic acid peroxide; and benzoyl peroxide.

8. The process of claim 1 , wherein the reaction mixture further comprises a reaction solvent.

9. The process of claim 8 , wherein the reaction solvent is selected from the group consisting of acetone, ethyl-3-ethoxypropionate, methyl amyl ketone, methylethylketone, methyl-iso-butylketone, N-methyl pyrrolidone, (propylene glycol monomethyl ether acetate, xylene, toluene, ethyl benzene, carbitol, cyclohexanol, dipropylene glycol (mono)methyl ether, n-butanol, n-hexanol, hexyl carbitol, iso-octanol, iso-propanol, methyl cyclohexane methanol, decyl alcohol, lauryl alcohol, myristal alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, and isoparaffins.

10. The process of claim 1 , wherein the (meth)acrylic monomer is selected from the group consisting of ethyl acrylate, methyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, acrylic acid, (meth)acrylic acid, hydroxy propyl (meth)acrylate, and hydroxy butyl(meth)acrylate.

11. The process of claim 1 , wherein the styrenic monomer comprises styrene or α-methylstyrene.

12. The process of claim 1 , wherein the styrenic monomer comprises styrene and the (meth)acrylic monomer comprises glycidyl (meth)acrylate.

13. The process of claim 1 , wherein the vinylic monomer comprises from about 40 to about 65 wt % of the styrenic monomer; and from about 35 to about 60 wt % (meth)acrylic monomer.

14. The process of claim 1 , wherein the reactor is a continuous stirred tank reactor (CSTR).

15. The process of claim 8 , wherein the solvent is present from about 10 wt % to about 40 wt %.