MDI-Epoxy Resin is synthesis at different parameters as I took different molar ratios of MDI with Epoxy, after getting the desired NCO%, I moved to the second step in which I added the calculated composition of Acrylic acid, after adding acrylic acid, the resin state changed into a white gel and my experiment failed, anyone tells me why it happened, and Whats Solution?
Could you share a paper and/or procedure you are following?
From your description, I understand that you obtain epoxy-MDI prepolymer with free NCO and epoxy groups. I believe that addition of acrylic acid opens an oxirane ring, producing new OH group. After that it likely reacts with free NCO groups, building molecular weight and cross-linking a structure into gel.
You could try to use an excess of epoxy component and prepare a prepolymer without a free NCO groups to check this.
If you need both acrylic and NCO functionality in your polymer, maybe you could try making acrylic-epoxy intermedia first and then add it to an excess of MDI.
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