Water-soluble polyphosphorodiamidates (PPDAs) and structural analog polyphosphates (PPEs) are synthesized by the metal-free radical thiol-ene polyaddition. To ensure complete water-solubility, we transform the thioether functionalities in the polymer backbone to sulfones by oxidation with peroxide. Due to a significant difference in the hydrolytic stability of P-N and P-O bonds, the chemical structure around the phosphorus atom in the main chain controls the degradation kinetics. The pendant ester group is used to further control the degradation rates of the polymers. Under acidic conditions, PPDAs show a fast and pH-dependent hydrolysis rate of the main chain, while PPEs are stable under such conditions, which was monitored by NMR spectroscopy. Under basic conditions, in contrast, the P-O-bonds can be hydrolyzed, while the P-amides are relatively stable. This set of hydrophilic and degradable polymers enlarges the family of phosphorus-containing polymers and might be useful in the field of drug delivery or tissue engineering and to date is the only route to prepare PPDAs by thiol-ene polymerization.

通过金属自由基硫醇-烯的加成反应，合成了水溶性聚二氨基磷酸二酯（PPDA）和结构类似物多磷酸盐（PPE）。为确保完全的水溶性，我们通过用过氧化物氧化将聚合物主链中的硫醚官能团转化为砜。由于PN和PO键的水解稳定性存在显着差异，因此主链中磷原子周围的化学结构控制着降解动力学。侧酯基团用于进一步控制聚合物的降解速率。在酸性条件下，PPDA显示出快速且依赖于pH值的主链水解速率，而PPE在这种条件下是稳定的，可通过NMR光谱监测。相反，在基本条件下，PO键可以水解，而对位酰胺相对稳定。这组亲水性和可降解聚合物扩大了含磷聚合物的种类，可能在药物递送或组织工程领域有用，并且迄今为止是通过硫醇-烯聚合制备PPDA的唯一途径。