Multilayer structures with common tie layer

1. A multilayer structure comprising:

a. a propylene polymer layer;

b. a styrene polymer layer;

c. a polyethylene layer; and

d. tie layers comprising:

(1) 25 to 75 wt % of an ethylene-C 4-8 α-olefin linear low density copolymer;

(2) 5 to 25 wt % of a polyethylene resin grafted with an ethylenically unsaturated carboxylic acid or acid derivative; and

(3) 20 to 50 wt % of a styrene-butadiene-styrene triblock copolymer having an MI of 18 to 35 dg/min.,

wherein the tie layers are the same and are positioned between adjacent layers of a-c.

2. The multilayer structure of claim 1 further comprising a barrier layer selected from EVOH, polyamides, co-extruded structures of EVOH and polyamides, polyvinylidene chloride, or polychlorotrifluoroethylene.

3. The multilayer structure of claim 2 wherein the barrier layer is selected from EVOH, polyamides or co-extruded structures of EVOH and polyamides.

4. The multilayer structure of claim 3 wherein the barrier layer is EVOH.

5. The multilayer structure of claim 3 wherein the polyamides are selected from nylon 6, nylon 6,6, nylon 12, nylon 6,12, nylon 6,66 or mixtures thereof.

6. The multilayer structure of claim 2 wherein the co-extruded structures of EVOH and polyamides are selected from polyamide/EVOH/polyamide or EVOH/polyamide.

7. The multilayer structure of claim 1 wherein the styrene polymer layer is a blend of polystyrene and high impact polystyrene.

8. The multilayer structure of claim 1 wherein the MI of the styrene-butadiene-styrene triblock copolymer is 20 to 30 dg/min.

9. The multilayer structure of claim 1 selected from PS/tie/barrier/tie/PP/tie/PE, HIPS/tie/barrier/tie/PE/tie/PP, PS/tie/barrier/tie/PE/tie/PP, HIPS/tie/barrier/tie/PP/tie/PE, PS+HIPS/tie/barrier/tie/PP/tie/PE or PS+HIPS/tie/barrier/tie/PE/tie/PP.

10. The multilayer structure of claim 9 selected from PS+HIPS/tie/barrier/tie/PP/tie/PE or PS+HIPS/tie/barrier/tie/PE/tie/PP.

11. A process comprising co-extruding a multilayer structure, the multilayer structure comprising:

a. a propylene polymer layer;

b. a styrene polymer layer;

c. a layer selected from polyethylene or co-extruded structures of polyethylene and ethylene-vinyl acetate copolymer; and

d. tie layers comprising:

(1) 25 to 75 wt % of an ethylene-C 4-8 α-olefin linear low density copolymer;

(2) 5 to 25 wt % of a polyethylene resin grafted with an ethylenically unsaturated carboxylic acid or acid derivative; and

(3) 20 to 50 wt % of a styrene-butadiene-styrene triblock copolymer having an MI of 18 to 35 dg/min.,

wherein the tie layers are the same and are positioned between adjacent layers of a-c.

12. The process of claim 11 further comprising a barrier layer selected from EVOH, polyamides, co-extruded structures of EVOH and polyamides, polyvinylidene chloride, or polychlorotrifluoroethylene.

13. The process of claim 11 wherein the MI of the styrene-butadiene-styrene triblock copolymer is 20 to 30 dg/min.

14. The process of claim 11 wherein the styrene polymer layer is a blend of polystryrene and high impact polystyrene.

15. The process of claim 12 wherein the barrier layer is selected from EVOH, polyamides or co-extruded structures of EVOH and polyamides.