The Preparation Of β-cyclodextrin High-molecular Polymers And Their Applications

As an excellent embedding adsorption material,β-cyclodextrin can form the embedding compounds with a variety of hydrophobic material, which could increase the the solubilization of hydrophobic drugs and also could protect and slow-release the sensitivity of natural pigment and natural hydrophobic medicine. Due to its poor solubility,β-CD is likely to precipitate from aqueous solution by crystallization, especially when fl-CD is formed the embedding compounds with the hydrophobic drugs or pigment. In order to increase the solubility of β-CD in the water, water-soluble β-CD polymers were synthesized through free radical copolymerization reaction with β-CD vinyl derivatives and other hydrophilic monomer.Supramolecular chemistry is a research hotspot of chemistry in recent years. Different from the traditional chemistry which is focused on the broken of the old chemical bonds and the formation of new one in the products, supramolecular chemistry is more focused on determination, identification and coordination between molecules. The β-CD can be formed embedding compounds with other chemical molecular, thus the research of independent outfit on β-CD becomes a typical representative and important research content in the field of supramolecular chemistry. This article also expect that the preparation of β-CD vinyl derivatives could provide a new way in the preparation of other β-CD polymers. In this paper, the main contents of the research include:β-CD maleate (CDM) and β-CD itaconate (CDI) were prepared by esterification of β-cyclodextrin (β-CD) with maleic acid and itaconic acid using phosphate as a catalyst in a semi-dry process. The esterification of β-CD was carried out using [Maleic acid] or [Itaconic acid] 4 mol/mol of CD; M/L ratio 1:0.6; temperature 110℃; [4-methoxyphenol] 2.5% amount of acid; reaction time 3.5h. The esterification rate of CDM and CDI are 70.38% and 21.02%, respectively. We found that CDM and CDI were both monoesters. Here, we also established a new evaluation method for the rate of esterification.The β-cyclodextrin-acrylamide copolymer (CDM-AM Ⅰ) was prepared from acrylamide and β-CD maleate (CDM) using K2S2O8 as initiator. The synthesis conditions of polymer CDM-AM (Ⅰ) were as follows:initiator concentration 0.02 mol/L; CDM:AM mass ratio 1:1 (CDM 3.6 g and AM 3.6 g); amount of water 10 ml; reaction temperature 70℃; reaction time 2 h; under those synthesis conditions, the yield of CDM-AM (Ⅰ) was 81% and the weight-average molecular weight was 40,500. The natamycin (NM) and carbendazim (MBC) could formed stable inclusion complexes with CDM-AM copolymer, and the solubility and fungicidal activity of the complexes were investigated. The stability constant of NM-CDM-AM (Ⅰ) and MBC-CDM-AM (Ⅰ) complexes at 303 K were of 10725.45 M-1 and 3000.89 M-1, respectively. The complexes were characterized using phase solubility diagrams, NMR spectra and UV spectra. The analysis of the biological activities of these two complexes indicated that they possessed enhancing fungicidal activities compared to NM and MBC alone.The β-cyclodextrin-acrylamide copolymer (CDM-AM Ⅱ) was prepared from acrylamide and β-CD maleate (CDM) using γ-ray as initiator. The synthesis conditions of polymer CDM-AM (Ⅱ) were as follows:CDM:AM mass ratio 1:1 (CDM 3.6 g and AM 3.6 g); irradiation dose 4 kGy; dosage of DMF aqueous solution 20 ml; under those synthesis conditions, the yield of CDM-AM (Ⅱ) was 75% and the weight-average molecular weight was 43,300. The natamycin (NM) and carbendazim (MBC) could formed stable inclusion complexes with CDM-AM copolymer, and the solubility and fungicidal activity of the complexes were investigated. The stability constant of NM·CDM-AM (Ⅱ) and MBC-CDM-AM (Ⅱ) complexes at 303 K were of 13,446.06 M-1 and 2,595.3 M-1, respectively. The complexes were characterized using phase solubility diagrams, NMR. spectra and UV spectra. The analysis of the biological activities of these two complexes indicated that they possessed enhancing fungicidal activities compared to NM and MBC alone.The β-cyclodextrin-N-Vinyl-2-pyrrolidone copolymer (CDM-NVP) was prepared from N-Vinyl-2-pyrrolidone (NVP) and β-CD maleate (CDM) using γ-ray as initiator. The synthesis conditions of polymer CDM-NVP were as follows:CDM:NVP mass ratio 1:0.7 (CDM 3.6 g and NVP 2.52 g); irradiation dose 4 kGy; dosage of DMF aqueous solution 20 ml; under those synthesis conditions, the yield of CDM-NVP was 84% and the weight-average molecular weight was 20, OOO.The natamycin (NM) and carbendazim (MBC) could formed stable inclusion complexes with CDM-NVP copolymer, and the solubility and fungicidal activity of the complexes were investigated. The stability constant of NM·CDM-NVP and MBC·CDM-NVP complexes at 303 K were of 12,988.54 M1 and 865.94 M-1, respectively. The complexes were characterized using phase solubility diagrams, NMR spectra and UV spectra. The analysis of the biological activities of these two complexes indicated that they possessed enhancing fungicidal activities compared to NM and MBC alone.