Processes for reducing color in polytrimethylene ether glycol polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorsHari Babu Sunkara, Hiep Quang Do
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Abstract
Processes for reducing color in PO3G are provided. The processes include contacting PO3G with an activated carbon and then separating the PO3G from the activated carbon by, for example, filtration. The process provides PO3G having an APHA color less than that before contact with the absorbent. The processes are desirably used for polymers having a molecular weight of about 250 to about 5000.
Claims16
A process consisting of contacting PO3G having an initial color with an adsorbent consisting of activated carbon and separating the PO3G and activated carbon, wherein the PO3G, after contact with the activated carbon, has an APHA color lower than the initial color wherein the PO3G is contacted with about 0.1 to about 5 weight % of the activated carbon based on the weight of the PO3G.
A process consisting of:
- a. providing reactant comprising 1,3-propanediol and polycondensation catalyst;
- b. polycondensing the reactant to PO3G having an initial color;
- c. contacting the PO3G with activated carbon;
- and
- d. separating the PO3G and activated carbon,
- such that the PO3G, after contact with the activated carbon, has a APHA color lower than the initial color herein the PO3G is contacted with about 0.1 to about 5 weight % of the activated carbon based on the weight of the PO3G, and then contacting is conducted at a temperature of about 100 to about 150° C.
A process consisting of contacting PO3G with activated carbon and separating the PO3G and activated carbon, wherein the PO3G has an initial APHA color, before contact with activated carbon, of about 70 to about 300, wherein the PO3G, after contact with the activated carbon, has an APHA color that is reduced by at least 10% as compared with the initial APHA color wherein the PO3G is contacted with about 0.1 to about 5 weight % of the activated carbon based on the weight of the PO3G.
Dependencies are inferred from the claim text.