Polymerization process

Abstract

A process for preparing a polymer comprising introducing a chain extending compound with a reactive compound into a first mixer; forming a homogenous mixture in the first mixer; transporting the homogenous mixture through at least one of a pipe reactor and a static mixer bed; delivering the homogenous mixture to a second mixer selected from a rotating arc mixer and a high viscosity mixer; and reacting the homogenous mixture with a capping agent in the second mixer.

Description

EXAMPLE 1

Sample 1 is made by a sequential melt reaction. 2350 g/hr of dry, molten 85° C. polyethylene glycol (“PEG”) (8000 M_w), 121 g/hr of 4,4′-methylene bis-(isocyanatocyclohexane) and 2.33 g/hr of dibutyltin dilaurate II (used to catalyze the reaction) are fed to the entrance of a RAM mixer (sold by CSIRO Thermal and Fluids Engineering, Australia). The two inch diameter RAM mixer rotates at 25 rpm and the jacket temperature is maintained at 85° C. At a distance of 30.5 cm down the 61 cm length of the tube, 85.2 g/min of Decanol is fed to the RAM mixer. The total reaction residence time is 30 minutes. Upon cooling, the resulting solid polymer has a molecular weight of 37,800 M_w and has a melt viscosity at 120° C. of 30 Pa·s (30 kcps) under a shear rate from 0.1 to 100 s⁻¹.

EXAMPLE 2

Sample 2 is made by a melt reaction in which all the feeds are fed to the entrance of the reactor. 2450 g/hr of dry, molten 85° C. PEG (molecular weight 8000), 55.0 g/hr of 1,6-diisocyanatohexane, 22.5 g/hr of hydrolytic trimerization of 1,6-hexamethylene diisocyanate, 42.7 g/hr of decanol and 3.63 g/hr of 28% bismuth(III) octoate (used to catalyze the reaction) are fed to the entrance of a RAM mixer. The two inch diameter RAM mixer rotates at 25 rpm and the jacket temperature is maintained at 85° C. The total reaction residence time is 30 minutes. Upon cooling, the resulting solid polymer has a molecular weight of 86,900 M_w and has a melt viscosity at 120° C. of 900 Pa·s (900 kcps) at the shear rate of 0.1 s⁻¹, and of 400 Pa·s (400 kcps) at the shear rate of 100 s⁻¹.

Claims

1. A process for preparing a polymer, comprising: introducing a chain extending compound with a reactive compound into a first mixer;forming a homogenous mixture in the first mixer;transporting the homogenous mixture through at least one of a pipe reactor and a static mixer bed;delivering the homogenous mixture to a second mixer selected from a rotating arc mixer and a high viscosity mixer; andreacting the homogenous mixture with a capping agent in the second mixer to form a capped polymer.

2. The process of claim 1 wherein the introducing comprises adding, as the reactive compound, at least one of a difunctional isocyanate, polyfunctional isocyanate, ester, amide, and acid and, as the chain extending compound, a polyol.

3. The process of claim 1 wherein the introducing comprises adding a catalyst to the first mixer.

4. The process of claim 1 wherein the forming comprises holding the homogeneous mixture in the first mixer for no more than 20 seconds at a temperature of 50° C. to 150° C.

5. The process of claim 1 wherein the transporting comprises: holding the homogenous mixture in the at least one the pipe reactor and static mixing bed for no more than 10 minutes.

6. The process of claim 1 wherein the reacting comprises: polymerizing the homogenous mixture at a temperature of 50° C. and 150° C.;adding the capping agent at least one of before and during polymer growth; andcollecting the capped polymer.

7. The process of claim 1 wherein the reacting comprises: allowing the homogeneous mixture to react in the second mixer for no more than 10 minutes.

8. The process of claim 1 further comprising solubilizing the capped polymer in an aqueous or solvent-aqueous solution.

9. A process for preparing a polyurethane, comprising: mixing a chain extending compound selected from the group consisting of monofunctional alcohols, polyols and polyamines and a polyisocyanate in a first mixer to form a homogenous mixture;delivering the homogenous mixture to at least one of a pipe reactor and a static mixer bed;holding the homogenous mixture in the at least one of a pipe reactor and a static mixer bed for no more than 45 minutes;transporting the homogeneous mixture to a second mixer selected from a rotating arc mixer and a high viscosity mixer; andreacting the homogeneous mixture with a capping agent in the second mixer.

10. The process of claim 9 further comprising: adding a catalyst to the first mixer;allowing the homogenous mixture to remain in the at least one the pipe reactor and static mixing bed for no more than 10 minutes; andperforming reactions of the homogenous mixture at a temperature of 50° C. to 150° C.