Synthesis of poly(succinimide) by bulk polycondensation ofL-aspartic acid with an acid catalyst

Abstract

The bulk polycondensation of L‐aspartic acid (ASP) with an acid catalyst under batch and continuous conditions was established as a preparative method for producing poly(succinimide) (PSI). Although sulfuric acid, p‐toluenesulfonic acid, and methanesulfonic acid were effective at producing PSI in a high conversion of ASP, o‐phosphoric acid was the most suitable catalyst for yielding PSI with a high weight‐average molecular weight (Mw) in a quantitative conversion; that is, the Mw value was 24,000. For the continuous process using a twin‐screw extruder at 3.0 kg · h−1 of the ASP feed rate, the conversion was greater than 99%, and the Mw value was 23,000 for the polycondensation with 10 wt % o‐phosphoric acid at 260°C. Sodium polyaspartate (PASP‐Na) originating from the acid‐catalyzed polycondensation exhibited high biodegradability and calcium‐ion‐chelating ability. The total organic carbon value was 86 ∼ 88%, and 100 g of PASP‐Na chelated with 5.5 ∼ 5.6 g of calcium ion, which was similar to the value for PASP‐Na from the acid‐catalyzed polycondensation with a mixed solvent © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 117–122, 2000

Poly(aspartic acid) Biohydrogel as the Base of a New Hybrid Conducting Material

“…The proton NMR spectrum of PSI in DMSO- d 6 is shown in Figure 2 b. Signals at 2.7 and 3.2 ppm were assigned to the methylene of the succinimide unit, while the signal at 5.3 ppm was attributed to the methine proton of the same unit [ 31 , 35 ]. Partially superimposed on these peaks can be found the DMSO solvent peak at 2.50 ppm and the residual water peak at about 3.33 ppm due to the hygroscopicity of the solvent [ 36 ].…”

The influence of pH, hydrolysis and degree of substitution on the temperature‐sensitive properties of polyaspartamides

“…Although PSI‐TS was first dissolved in a solution of pH 3.2 to avoid the hydrolysis of succinimide, carboxyl groups are present in very low quantity in the structure of PSI as end groups and open‐ring structures. These results demonstrate the influence of the DH in the temperature‐sensitive behavior of polyaspartamides …”

Biodegradable and pH-Responsive Nanoparticles Designed for Site-Specific Delivery in Agriculture

“…PSI was synthesized by acid-catalyzed condensation polymerization of l -aspartic acid ( M n = 13 500; M w / M n = 1.52). , The resulting polymer was partially functionalized by reaction with N -alkyl primary amines or via partial hydrolysis with NaOH to yield amphiphilic PSI derivatives (Scheme ). The resulting polymers were dissolved in DMF and precipitated into water to form stable polymeric nanoparticles.…”