Novel solvent-free synthesis and modification of polyaspartic acid hydrogel

Abstract

Polyaspartic acid (PASP) hydrogel, a hydrolysis derivative of polysuccinimide (PSI), has been previously synthesized by using organic solvents such as dimethyl formamide (DMF) or dimethyl sulfoxide (DMSO), making the process environmentally and economically unattractive. The present paper presents a ''green'' synthesis, without using organic solvents. It demonstrates that hydrolysis and modification can be combined with in situ cross-linking. Introducing an aqueous soluble crosslinker, experimental results would broaden the application area of PASP at significantly reduced preparation cost, whilst moreover improving the required properties. The PASP hydrogel obtained by this method has a 600 g g 21 water-swelling ratio against 420 g g 21 as obtained by the conventional method using DMF. To reduce the ionic strength sensitivity of the hydrogel, sulfo-groups from, e.g. taurine, can be grafted onto the main chain of PASP and produce a modified PASP hydrogel with a 300 g g 21 water-swelling ratio in a 0.9% sodium chloride solution, against only 80 g g 21 for the nongrafted PASP hydrogel.

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

“…Because of the reactivity of PSI toward primary amines, previous reports have involved various moieties being readily incorporated onto the PSI backbone to give fully functionalized PASP derivatives. Alternatively, PSI has been partially functionalized, with the remaining succinimidyl units being hydrolyzed to give PASP copolymers. , Additionally, many groups have incorporated stimulus-responsive moieties onto the PSI backbone (i.e., hydrazone bonds, ,− amines, ,, thiols and disulfides, − carboxyls, , imidazole, etc.) to impart responsiveness onto the biodegradable PASP backbone.…”

Polyaspartic Acid-Derived Micro-/Mesoporous Carbon for Ultrahigh H2 and CH4 Adsorption

“…PSI was condensation polymerized by ASP using H 3 PO 4 as a catalyst. According to previous work, − the reaction was carried out at 210 °C under −0.09 MPa for 8 h, and the mass ratio of ASP to H 3 PO 4 was 2:1. After the polymerized product was pulverized to 60–80 mesh, it was washed with deionized water until neutral and dried for 12 h at 120 °C.…”

Preparation of MPASP‐PAA/Fe3+ Composite Conductive Hydrogel with Physical and Chemical Double Crosslinking Structure and Its Application in Flexible Strain Sensors

“…So PASP is widely used in water treatment, biomedicine, agriculture, daily chemical and other fields. [15][16][17][18] In this paper, a biodegradable macromolecular crosslinking agent modified polyaspartic acid (MPASP) was obtained by modifying polysuccinimide with ethanolamine and acryloyl chloride, and the MPASP-PAA/Fe 3+ composite conductive hydrogel with physical and chemical double crosslinking structure was prepared by using MPASP as the chemical crosslinking agent and FeCl 3 as the physical crosslinking agent. The Fe 3+ can interact with the carboxylic acid groups to form physical crosslinks, which can increase the toughness of the conductive hydrogel.…”

“…So PASP is widely used in water treatment, biomedicine, agriculture, daily chemical and other fields. [ 15–18 ]…”