| Poly(aspartic acid)(PAsp) absorbent resin is a novel biodegradable material with a large number of hydrophilic groups such as carboxyl group and amino group, which features three-dimensional network structure and be able to swell in aqueous solutions without dissolution. However, the application fields of pure PAsp are limited due to its various defects, such as simple uni-structure, poor thermal stability and salt resistance, high costs etc. Therefore, in this paper polysuccinimide(PSI) was synthesized from L-Aspartic acid through thermal polycondensation, KPAsp/P(AAc-AM) interpenetrating polymer network and KPAsp/PAAc/MATP Composite Absorbent Resin were prepared based on PSI modified with γ-aminpropyltriethoxysilane(KH550)(KPSI), poly(arylic acid), modified Attapulgite(ATP) and acrylamide(AM) as raw materials, potassium persulfate(KPS) as the free radical initiator, N,N’-methylenebisacrylamide(MBA) as the crosslinker, respectively. Effects of factors on the absorbing abilities of the absorbent resins were investigated. In addition, composition, morphology, absorbing properties and sensivities of the absorbent resins were also studied.Firstly, KPAsp/P(AAc-AM) interpenetrating polymer network absorbent resin was synthesized and effects of synthetic parameters on the absorbing properties of KPAsp/P(AAc-AM) IPNAP were studied. Results showed that when the mass ratio of KPSI to AAc-AM was 1:2, the mass ratio of AM to AAc-AM was 0.2, the content of initiator was 0.9wt%, the content of crosslinking agent was 0.1wt%, the content of KH550 was 2 mol% of PSI, the neutralization degree of AAc was 75%, the swelling ratio of KPAsp/P(AAc-AM) IPNAP in distilled water and 0.9wt% NaCl solution reached 713.5 g/g and 145.4 g/g, respectively, which were 3.92- and 2.27-fold when compared with KPAsp resin. And it was found that the KPAsp/P(AAc-AM) IPNAP exhibit quite good salt resistance. The results of swelling behaviors in various mediums showed that IPNAP had remarkable temperature-, pH-, and salt- sensitivities. And results of FT-IR、SEM、TGA characterization indicated that IPNAP prepared was composed of modified Poly(aspartic acid)(KPAsp) and P(AAc-AM), the incorporation of P(AAc-AM) significantly improved the pore structure of the resin, and IPNAP had better thermal stability than KPAsp.While the properties of PAsp can be improved through the formation of Bipolymers, Terpolymers and interpenetrating polymer network polymers, it costs too much. It was assumed to be an effective method to reduce the costs by introducting of cheap inorganic, espically clays, into the resin. Absorbent resins with excellent properties of absorption and salt tolerance will be prepared at the same time.In this work, attapulgite was modified with hydrochloric acid firstly, and a novel Composite Resin with good properties based on poly(asprtic acid) modified with γ-aminpropyltriethoxysilane(KH550), poly(arylic acid) and modified attapulgite(MATP) was prepared through a simple one-step method in an aqueous system. Resins prepared and Attapulgite were characterized by Fourier transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), thermogravimetric analysis(TGA) and X-ray diffraction(XRD), effects of synthetic parameters on the absorbing properties, sensitivity to environmental media and swelling behavior of the composite resin were studied. Results showed that when the content of MATP was 5wt%, the content of initiator was 0.8wt%, the content of crosslinking agent was 0.1wt%, the reaction temperature was 70℃, the maximum swelling ratios of the composite resin were reached in distilled water and physiological saline, corresponding to 805.2 g/g and 120.3 g/g, respectively, which were obviously better than KPAsp resin. |
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