Tochwin Anna, El-Betany Alaa, Tai Hongyun, Chan Kai Yu, Blackburn Chester, Wang Wenxin
School of Chemistry, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
Charles Institute of Dermatology, University College Dublin, Dublin 4, Ireland.
Polymers (Basel). 2017 Sep 13;9(9):443. doi: 10.3390/polym9090443.
Here, we report the synthesis of new thermoresponsive hyperbranched polymers (HBPs) via one-pot reversible addition-fragmentation chain transfer (RAFT) copolymerisation of poly(ethylene glycol)methyl ether methacrylate (PEGMEMA, = 475 g/mol), poly(propylene glycol)methacrylate (PPGMA, = 375 g/mol), and disulfide diacrylate (DSDA) using 2-cyanoprop-2-yl dithiobenzoate as a RAFT agent. DSDA was used as the branching agent and to afford the HBPs with reducible disulfide groups. The resulting HBPs were characterised by Nuclear Magnetic Resonance Spectroscopy (NMR) and Gel Permeation Chromatography (GPC). Differential Scanning Calorimetry (DSC) was used to determine lower critical solution temperatures (LCSTs) of these copolymers, which are in the range of 17⁻57 °C. Moreover, the studies on the reducibility of HBPs and swelling behaviours of hydrogels synthesized from these HBPs were conducted. The results demonstrated that we have successfully synthesized hyperbranched polymers with desired dual responsive (thermal and reducible) and crosslinkable (via thiol-ene click chemistry) properties. In addition, these new HBPs carry the multiplicity of reactive functionalities, such as RAFT agent moieties and multivinyl functional groups, which can afford them with the capacity for further bioconjugation and structure modifications.
在此，我们报道了通过聚（乙二醇）甲基醚甲基丙烯酸酯（PEGMEMA，Mn = 475 g/mol）、聚（丙二醇）甲基丙烯酸酯（PPGMA，Mn = 375 g/mol）和二硫代二丙烯酸酯（DSDA）的一锅法可逆加成-断裂链转移（RAFT）共聚反应，以2-氰基丙-2-基二硫代苯甲酸酯作为RAFT试剂，合成新型热响应性超支化聚合物（HBP）。DSDA用作支化剂，以使HBP带有可还原的二硫键基团。所得HBP通过核磁共振光谱（NMR）和凝胶渗透色谱（GPC）进行表征。差示扫描量热法（DSC）用于测定这些共聚物的低临界溶液温度（LCST），其范围为17⁻57 °C。此外，还对HBP的可还原性以及由这些HBP合成的水凝胶的溶胀行为进行了研究。结果表明，我们已成功合成出具有所需双重响应（热响应和可还原响应）和可交联（通过硫醇-烯点击化学）性能的超支化聚合物。此外，这些新型HBP带有多种反应性功能团，如RAFT试剂部分和多乙烯基官能团，这使其具有进一步生物共轭和结构修饰的能力。
