| 摘要 |
<p>Disclosed is a compound of the formula or a mixture thereof; wherein R and R′are the same or different, and wherein R and R′are independently selected from an alkyl group, an arylalkyl group, or an alkylaryl group, wherein the alkyl group, the arylalkyl group, or the alkylaryl group has from about 18 to about 60 carbon atoms; and wherein m is an integer of from about 1 to about 30.</p> |
