Poly(alkylene phosphate)s by polycondensation of phosphonic diamides with diols

Abstract

Polycondensation of diols with phosphonic bis(dialky1amide)s leads to high-molecular-weight polyphosphites (a, up to 4 . lo4). Model reactions of 1-butanol, 2-butanol and phenol with phosphonic bis(diethy1amide) (1) were studied and it was established, that these reactions exhibit characteristic induction periods. Linearization of the kinetic curves after addition of amines prior to reaction enabled us to postulate the mechanism of esterification, involving activation of 1 by hydrogen-bonding to amines. However, the major side reaction lowering the degree of polymerization was found to be dealkylation of the formed ester units by added and/or evolved amine. Therefore, in order to increase the rate of polycondensation and to prevent the formed polymer chain from breaking down by dealkylation, the process was conducted at increased temperature (90°C) in a nonsolvent for the polymer of higher molecular weight. Thus, the polymer separates from the major solution and becomes less prone to dealkylation.

The Use of Transesterification Method for Obtaining Phosphorus‐Containing Polymers

“…On the other hand, the first PPE with high molecular weight was prepared more than 20 years ago by using ROP. 8,9,20,[23][24][25][26]33,[56][57][58][59][60][61][62][63][64][65] The initial attempts to prepare high molecular weight polyphosphonates esters by the transesterification method were unsuccessful. 8,9,20,[23][24][25][26]33,[56][57][58][59][60][61][62][63][64][65] The initial attempts to prepare high molecular weight polyphosphonates esters by the transesterification method were unsuccessful.…”

“…In the last 30 years, a variety of different polyphosphonates and polyphosphate esters have been produced 8,9,20,[23][24][25][26]33,[56][57][58][59][60][61][62][63][64][65] and transesterification is one of the most important method used in the field. This transesterification method described by Myrex et al 56 showed several advantages.…”

“…These polymers, as shown in Fig. [2][3][4][5][6][7][8][9][10] During the last decades, the development of PPEs chemistry showed the possibility of obtaining PPEs with various structures. [2][3][4][5][6][7][8][9] Polyphosphates with P-O bonds are suitable for flameretardation applications.…”

“…1, can be prepared by polycondensation of dimethyl phosphonate with diols by ring-opening polymerizations (ROPs) of cyclic phosphites and transesterification of polyphosphonate oligomers. [2][3][4][5][6][7][8][9] Polyphosphates with P-O bonds are suitable for flameretardation applications. These polyphosphates were investigated as biomaterials in the past decades (in drug/gene delivery and tissue engineering fields).…”

Recent Progress in Polyphosphoesters: From Controlled Synthesis to Biomedical Applications

“…They have studied extensively the synthesis of these polymers, obtained by various routes, such as ring-opening polymerization (ROP), polycondensation, and polyaddition. [4][5][6][7] Since the 1980s, several groups, representatives including Leong's and Zhuo's groups, have explored the biomedical applications of PPEs, initially for controlled drug delivery. [8][9][10][11][12][13][14][15] Since the late 1990s, taking advantage of the versatility of the PPE's pendant groups, they have conjugated various groups to PPEs for gene delivery and tissue engineering applications.…”