I am waiting for a decision on Social Security Disability. I am 53, can I collect from my ex husband's social security?

Here is the answer to your question directly from the SSA website.

Question:
Can my ex-spouse get some of my Social Security benefits?

Answer:

If you are divorced (even if you have remarried), your ex-spouse may qualify for benefits on your record if you are 62 or older. In some situations, he or she may get benefits even if you're not receiving them yet. (If your ex-spouse also receives a pension based on work not covered by Social Security, such as government work, his or her Social Security benefit on your record may be affected.)

To qualify on your record, your ex-spouse must:

Have been married to you for at least 10 years;
Be at least 62 years old;
Be unmarried; and
Not be eligible for an equal or higher benefit on his or her own Social Security record, or on someone else’s Social Security record.
NOTE: The amount of benefits your divorced spouse gets has no effect on the amount of benefits you or your current spouse may receive.

Therefore, based on the facts as your stated in your question.

First marriage does not qualify because less than 10 years.

Second marriage does meet the 10 year requirement, however, you are not yet 62 years of age. And finally, you do not state whether you are unmarried.

Stanley Dale Radtke, Esq.
Law Offices of Haitham Edward Ballout
220 Montgomery Street, Suite 416
San Francisco, CA 94014
415-252-1234