Macromolecular antioxidants based on sterically hindered phenols and phosphites
Sterically hindered phenol and phosphite based compounds, represented by formula I: and their use as antioxidants in a wide range of materials including, but not limited to, food, plastics, elastomers, composites and petroleum based products is disclosed herein.
1. A method of synthesizing a macromonomer represented by a structural formula selected from I:
wherein:
R is:
R 1 and R 2 in each occurrence, independently is an optionally substituted alkyl or optionally substituted aryl;
X and Y in each occurrence, independently is a bond, —O—, —NH—, —C(O)NH—, —NHC(O)—, —C(O)O—, —OC(O)— or —CH 2 —;
n and m in each occurrence, independently is 0 or a positive integer;
i and j in each occurrence, independently is 0, 1, 2, 3 or 4; and
R″ is an optionally substituted alkyl;
comprising the step of mixing R ++ with a phosphorous containing compound, wherein R ++ is:
in a solvent and under conditions that cause at least partial reaction of R ++ with the phosphorous containing compound.
2. The method of claim 1 , wherein the phosphorous containing compound is phosphorous trichloride.
3. The method of claim 2 , wherein the solvent includes dichloromethane.
4. The method of claim 3 , wherein R ++ and the phosphorous containing compound are mixed at a temperature in a range of between about 5° C. and about −5° C.
5. The method of claim 4 , wherein R ++ and the phosphorous containing compound are mixed at a temperature of about 0° C.