CHCl3/triethanolamine: a new mixed solvent for preparing high-molecular-weight main-chain benzoxazines through Mannich-type polycondensation was written by Wang, Ping;Liu, Xuya;Lai, Hua;Li, Wei;Huang, Geng;Li, Yulin;Yang, Po. And the article was included in Polymer Journal (Tokyo, Japan) in 2022.Application of 620-92-8 The following contents are mentioned in the article:
Abstract: Mannich-type polycondensation with 4,4′-diaminodiphenylmethane (DDM), 2,2-bis(4-hydroxyphenol) propane (BPA) and paraformaldehyde (PF) in different solvents was carried out to prepare main-chain benzoxazines. When pure CHCl3 was used as the solvent, the decomposition rate of PF in CHCl3 was very slow, thus preventing gelation caused by the formation of triazine in the early reaction, producing P(B-D)1 composed of partially closed and unclosed structures. The addition of alk. triethylamine into CHCl3 (CHCl3/triethylamine = 6:1) greatly enhanced the decomposition rate of PF but gave a large triazine gel. The introduction of triethanolamine into CHCl3 was found to promote the decomposition of PF, enhance the polymerization rate, and prevent gelation caused either by the formation of triazine or by the ring-opening of oxazine ring through a solvation effect. Polymers P(B-D) 6P(B-D)8 obtained in CHCl3/triethanolamine had a high-oxazine content and a high number mol. weight (Mn) near 8000. Further optimization of Mannich-type polycondensation in CHCl3/triethanolamine gave preferred conditions: a CHCl3/triethanolamine ratio of 4:1, a PF of 1.2 equiv and a reaction time of 24 h. Compared with P(B-D)1 and P(B-D)3 (obtained in toluene/ethanol), P(B-D)9 obtained under the optimized conditions showed a higher Mn (10,000) and a higher yield (97.0%). The optimized conditions were also applicable for other kinds of diamines and bisphenols. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Application of 620-92-8).
4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Similar to water, an alcohol can be pictured as having an sp3 hybridized tetrahedral oxygen atom with nonbonding pairs of electrons occupying two of the four sp3 hybrid orbitals. Under carefully controlled conditions, simple alcohols can undergo intermolecular dehydration to give ethers. This reaction is effective only with methanol, ethanol, and other simple primary alcohols.Application of 620-92-8
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts