A preparation method of polylactic acid material with x-ray imaging function

[0021] Example 1:

[0022] Mix pre-vacuum-dehydrated double-terminated hydroxy polylactic acid with a molecular weight of 650 and 4,4'-diphenylmethane diisocyanate in N,N-dimethylformamide at a molar ratio of 0.75:1, under nitrogen protection The reaction was stirred and mixed at 80° C. for 2 hours to obtain a prepolymer; and iodophenylenediamine (see structural formula I) pre-dissolved in N,N-dimethylformamide was added, which was mixed with 4,4′-diphenylene The molar ratio of methyl methane diisocyanate is 0.25:1, and the stirring reaction takes about 2 hours to discharge.

[0023] Example 2:

[0024] The pre-vacuum-dehydrated double-terminated hydroxy polylactic acid with a molecular weight of 1000 and toluene diisocyanate were mixed in dimethyl sulfoxide, the mixing molar ratio was 0.50:1, and the reaction was stirred and mixed at 100 ° C for 4 hours under the protection of nitrogen to obtain a prepolymer. Then add iodo bisphenol A (see structural formula II), and the molar ratio of it and toluene diisocyanate is 0.50:1, and the reaction is stirred for about 4 hours to discharge.

[0025] Example 3:

[0026] Mix the pre-vacuum dehydrated double-terminated hydroxy polylactic acid with a molecular weight of 2000 and isophorone diisocyanate in N,N-dimethylformamide, the mixing molar ratio is 0.40:1, and stir and mix at 80 ° C under nitrogen protection The reaction was carried out for 2 hours to obtain a prepolymer; bromobutanediamine (see structural formula III) was added, and the molar ratio of it and isophorone diisocyanate was 0.55:1, and the reaction was stirred for about 1 hour to discharge.