High melt strength polypropylene and process of preparation thereof

1. A high melt strength resin composition comprising a) non-functionalized polypropylene, b) at least one acrylate comprising at least one of zinc diacrylate, calcium diacrylate or aluminum triacrylate in a total amount of from 0.1 to 5% by weight based on the weight of non-functionalized polypropylene, and c) at least one acid neutralizer in a total amount of from 0.005 to 5% by weight based on the total weight of the at least one acrylate.

2. The high melt strength resin composition of claim 1 , wherein the acid neutralizer comprises at least one of metal oxides, metal hydroxides, alkali metal hydroxides, alkali metal carbonates, alkaline earth metal oxides, alkaline earth metal carbonates, alkali metal bicarbonates, metal carboxylates, alkali metal carboxylates, alkaline earth metal carboxylates and combinations thereof.

3. The high melt strength resin composition of claim 1 , wherein the acid neutralizer comprises at least one of zinc oxide, zinc hydroxide, calcium oxide, barium oxide, magnesium oxide, titanium dioxide, sodium carbonate, sodium bicarbonate, calcium carbonate, magnesium carbonate, sodium hydroxide, potassium hydroxide, zinc salts of fatty acids, calcium salts of fatty acids, or combinations thereof.

4. The high melt strength resin composition of claim 1 , wherein the at least one acid neutralizer comprises zinc oxide.

5. The high melt strength resin composition of claim 1 , comprising zinc diacrylate.

6. The high melt strength resin composition of claim 1 , wherein the resin composition is free of organic peroxide.

7. The high melt strength resin composition of claim 1 , wherein the non-functionalized polypropylene has a melt flow index (MFI) of from 0.2 to 2000 g/10 min (2.16 Kg, 230° C.).

8. The high melt strength resin composition of claim 1 , wherein the non-functionalized polypropylene is at least one of polypropylene homopolymers, polypropylene copolymers, or alloys of polypropylene with at least one additional polymer.

9. The high melt strength resin composition of claim 1 , wherein the non-functionalized polypropylene is prepared using at least one Ziegler-Natta catalyst.

10. The high melt strength resin composition of claim 1 , wherein the non-functionalized polypropylene is prepared using at least one metallocene catalyst.

11. The high melt strength resin composition of claim 1 , wherein the non-functionalized polypropylene is prepared using free-radical initiation.

12. The high melt strength resin composition of claim 1 , comprising 0.5 to 3% by weight of the at least one acrylate.

13. The high melt strength resin composition of claim 1 , additionally comprising one or more of antioxidants, fillers other than acid neutralizers, colorants other than acid neutralizers, fire retardants other than acid neutralizers, blowing agents other than acid neutralizers, clarifiers, anti-scratch additives, anti-dust additives, nucleating agents, or stabilizers.

14. A method of making a high melt strength polypropylene, comprising the step of

compounding, at a processing temperature between 185° C. and 260° C., a resin composition comprised of

a) non-functionalized polypropylene;

b) at least one acrylate comprising at least one of zinc diacrylate, calcium diacrylate and aluminum triacrylate in a total amount of from 0.1 to 5% by weight based on the weight of the non-functionalized polypropylene; and

c) at least one acid neutralizer in a total amount of from 0.005 to 5% by weight based on the total weight of the at least one acrylate.

15. The method of claim 14 , wherein the processing temperature is between 220° C. and 240° C.

16. The method of claim 14 , wherein the processing temperature is about 230° C.

17. The method of claim 14 , wherein the compounding is carried out using a single or twin screw extruder, a banbury mixer, or a roll mill.

18. The method of claim 14 , wherein the at least one of the zinc diacrylate, calcium diacrylate or aluminum triacrylate; or the acid neutralizer are in the form of a masterbatch comprising a polyolefin as a carrier resin for the masterbatch.

19. The method of claim 14 , wherein the resin composition is melt extruded.

20. The method of claim 14 , whereby an acrylate moiety from the at least one of the zinc diacrylate, calcium diacrylate or aluminum triacrylate is grafted to the non-functionalized polypropylene as a result of the compounding.

21. A high melt strength polypropylene obtained by compounding a resin composition comprised of a) non-functionalized polypropylene, b) at least one acrylate comprising at least one of zinc diacrylate, calcium diacrylate or aluminum triacrylate in an amount of from 0.1 to 5% by weight based on the weight of the non-functionalized polypropylene, and c) at least one acid neutralizer in a total amount of from 0.005 to 5% by weight based on the total weight of the at least one acrylate at a processing temperature between 185° C. and 260° C.

22. The high melt strength polypropylene of claim 21 , wherein the processing temperature is between 220° C. and 240° C.

23. The high melt strength polypropylene of claim 21 , wherein the processing temperature is about 230° C.

24. The high melt strength polypropylene of claim 21 , having an elongational viscosity of at least 1,000,000 Pa·s measured at a strain rate of 0.1 s −1 at 170° C.

25. The high melt strength polypropylene of claim 21 , having an elongational viscosity of at least 500,000 Pa·s measured at a strain rate of 0.1 s −1 at 170° C.

26. The high melt strength polypropylene of claim 21 , having an elongational viscosity at least 25% higher than an elongational viscosity of the non-functionalized polypropylene measured at a strain rate of 0.1 s −1 at 170° C.

27. The high melt strength polypropylene of claim 21 , having an elongational viscosity measured at a strain rate of 0.1 s −1 at 170° C. of from 25% to 2000% higher than an elongational viscosity of the non-functionalized polypropylene.

28. The high melt strength polypropylene of claim 21 , wherein the compounding is carried out using a single or twin screw extruder, a banbury mixer, or a roll mill.

29. The high melt strength polypropylene of claim 21 , wherein the resin composition is melt extruded.

30. The high melt strength polypropylene of claim 21 , wherein an acrylate moiety from the zinc diacrylate, calcium diacrylate or aluminum triacrylate is grafted to the non-functionalized polypropylene to provide acrylate-functionalized polypropylene chains and grafted acrylate groups on the acrylate-functionalized polypropylene chains are present in the form of polyvalent metal or alkaline earth metal salts.

31. The high melt strength polypropylene of claim 21 , wherein the at least one of the zinc diacrylate, calcium diacrylate or aluminum triacrylate; or the acid neutralizer are in the form of a masterbatch comprising a polyolefin as a carrier resin for the masterbatch.

32. A polymeric article comprising the high melt strength polypropylene of claim 21 .

33. The polymeric article of claim 32 , wherein the polymeric article is a foamed article, a sheet extruded article, a thermoformed article, a blow molded article, a roto-molded article, an extrusion-coated article, a cast article, an injection molded article, a pressed article, a fiber or a film.

34. The high melt strength resin composition of claim 1 , comprising from 0.1 to 2% by weight of the at least one acrylate based on the weight of non-functionalized polypropylene, and from 0.005 to 2% by weight of the at least one acid neutralizer based on the total weight of the at least one acrylate.