Systems and processes for polymer production

1. A method for producing a polypropiolactone composition, comprising: combining beta propiolactone and at least one salt of a compound of Formula (III) to produce the polypropiolactone composition, wherein:

the compound of Formula (III) has the structure:

wherein p is independently an integer from 0 to 9;

the at least one salt of the compound of Formula (III) independently comprises:

an anion of the compound of Formula (III), and

a cation selected from the group consisting of quaternary ammonium, protonated amine, iminium, guanidinium, phosphonium, phosphazenium, sulfonium, arsonium, and a cation of a nitrogen-containing heterocycle, or any combination thereof; and

the polypropiolactone composition comprises polypropiolactone polymers, or salts thereof, independently comprising:

(a) an acrylate end group having the structure

 and

(b) a polymer chain comprising repeating units having the structure

 wherein the acrylate end group caps the alkyl terminus of the polymer chain, and wherein:

(1) the polypropiolactone composition has an M n less than or equal to about 40,000 g/mol; and

(2) the polypropiolactone composition has a polydispersity less than or equal to about 2.0; and

(3) at least 90 wt % of the polypropiolactone composition comprises polypropiolactone polymers, or salts thereof, having the acrylate end group.

2. The method of claim 1 , wherein the polypropiolactone polymers, or salts thereof, independently have a structure of Formula (I):

wherein:

n is an integer from 10 to 1,000; and

Y is H or a cation.

3. The method of claim 1 , wherein the beta propiolactone is combined with the at least one salt of the compound of Formula (III) at a temperature greater than 50° C.

4. The method of claim 3 , wherein the temperature is in the range from 140° C. to 200° C.

5. The method of claim 1 , wherein at least 95 wt % of the polypropiolactone composition comprises polypropiolactone polymers, or salts thereof, having the acrylate end group.

6. The method of claim 2 , wherein at least 90 wt % of the polypropiolactone composition comprises polypropiolactone polymers, or salts thereof, having the structure of Formula (I).

7. The method of claim 2 , wherein the polypropiolactone composition has a polydispersity index (PDI) less than 1.7.

8. The method of claim 1 , wherein p is 0.

9. A method of producing a superabsorbent polymer, comprising:

converting a polypropiolactone composition of claim 1 to produce acrylic acid, and

polymerizing the acrylic acid blended with sodium hydroxide in the presence of a radical initiator to produce the superabsorbent polymer.

10. A superabsorbent polymer produced according to the method of claim 9 .

11. The method of claim 1 , wherein the combining of beta propiolactone and the at least one salt of the compound of Formula (III) produces a chain transfer agent, wherein the chain transfer agent is at least one salt independently comprising an acrylate end group having the structure

wherein the acrylate end group caps the alkyl terminus of the polymer chain.

12. The method of claim 11 , wherein the chain transfer agent is at least one salt independently further comprising: a chain comprising one or more units having the structure

13. The method of claim 8 , wherein the at least one salt of the compound of Formula (III) comprises a cation selected from the group consisting of ammonium, protonated amine, and iminium.

14. The method of claim 13 , wherein the ratio of the beta propiolactone to the at least one salt of the compound of Formula (III) is between 1:9,000 and 1:14,500.

15. The method of claim 1 , wherein the beta propiolactone and the at least one salt of the compound of Formula (III) are further combined with a compound of Formula (III).