Plexiglas: from synthetic glass to cationic exchanging resin

Istituto di Istruzione Superiore Galileo Galilei Jesi
Noor Gholam;Elisa Ausili;Lorenzo Soverchia


Plexiglas is a macromolecule (poly-methyl-methacrylate) obtained by polymerization of the Methyl Methacrylate. Cation exchanging resins have acidic groups such as COOH (carboxyl) and SO3H (sulfonic) which fix metallic cations dissolved in water releasing an equivalent of protons through the following reaction: 2 RCOOH + Me2+ (RCOO)2Me + 2 H+ Regeneration is made treating the exhausted resin with diluted hydrochloric acid (HCl) which moves the equilibrium to the left. The aim of our research is to re-use the discarded Plexiglas by transforming it into a cationic exchanging resin. Alkaline hydrolysis transforms the COOCH3 group into COO– group; the obtained group is then transformed into COOH group by means of a treatment with HCl. After the alkaline hydrolysis spectra of the solid show the characteristic band of the asymmetric stretching of the COO– (1610-1550) at 1567 (1st experiment) and at 1555 (2nd experiment). Instead after the acidic treatment the spectra of the solid show that this band has disappeared. On the contrary the characteristic band of the OH stretching of the COOH group (3300-2500) at 3228 (1st experiment) and at 3200 (2nd experiment) appears. The water hardness, due to Ca2+ and Mg2+ ions, is studied to verify the capability of the obtained resin to capture these cations. For this purpose, some mineral water is percolated through the micro-columns. There are three experimental evidences to validate the hypothesis: EDTA molecule (Ethylene Di-amino Tetra-Acetic acid, disodium salt) to estimate hardness is not required The pH of the percolated water through the column decreases from 8 of the mineral water without any treatment, to 6.3 after the treatment as expected The spectrum recorded in the visible range of the percolated mineral water through the column plus EBT (Eriochrome Black T) indicator is the same as the spectrum obtained using de-ionized water plus the same amount of EBT In conclusion, the study has provided evidence that it is possible to convert Plexiglas into cationic exchanging resin.

「為配合國家發展委員會「推動ODF-CNS15251為政府為文件標準格式實施計畫」,以及 提供使用者有文書軟體選擇的權利,本館檔案下載部分文件將公布ODF開放文件格式, 免費開源軟體可至LibreOffice 下載安裝使用,或依貴慣用的軟體開啟文件。」

檔案名稱 檔案大小 格式
Plexiglas: from synthetic glass to cationic exchanging resin 1 MB Adobe Reader(Pdf)檔案