Synthesis of UV‐curable hyperbranched polyurethane (meth)acrylate oligomers via thiol‐ene “click” chemistry

Abstract

First, the second‐generation hyperbranched poly(amine‐ester) (G2‐OH) was successfully prepared by thiol‐ene “click” chemistry. Subsequently, a series of photosensitive hyperbranched oligomers (G2‐ORs) were synthesized by facile modifications of the G2‐OH with acryloyl chloride, methacryloyl chloride, IPDI‐HEA, and IPDI‐HEMA, respectively. The structures of hyperbranched oligomers were characterized by element analysis, FT‐IR, 1H NMR, GPC and viscosity measurement. It was shown that these synthesized oligomers have narrow molecular weight distribution and low intrinsic viscosity at 30°C. UV–vis spectra results showed that the G2‐ORs had sharp absorption bands at around 202 nm. The results of photosensitivities measurement indicated that the G2‐Macr shows the highest photosensitive than other hyperbranched oligomers in the absence of photoinitiator. In addition, these UV‐cured photosensitive G2‐ORs had good thermal properties. The solubilities of the synthesized hyperbranched oligomers were also examined. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

UV‐curable polyurethane acrylate resin containing multiple active terminal groups for enhanced mechanical properties

“…It is worth noting that the two ─NCO groups in IPDI have distinct reaction activity . The reaction activity of ─NCO on the hexatomic ring (Position a) is higher than that on the side chain (Position b) . Thus, the selective reaction between ─OH group of HEMA and ─NCO group on the hexatomic ring can be preferentially carried out in Step 1 by controlling the reaction at a lower temperature of 60 °C.…”

Synthesis of a branched photosensitive copolymer and its application for negative‐type photoresists

“…However, all of the TGA curves of the copolymers showed complicated and mainly two‐stage decompositions. The first stage of weight loss, occurring from 180 to 250°C, was attributed to the degradation of the terminal groups grafted by HEMA . The second stage, appearing from 250 to 300°C, was ascribed to polymer chain degradation, a complex process including double‐bond thermal crosslinks, and the weight loss in this stage reached a maximum …”

Recent Advances in Click Chemistry Applied to Dendrimer Synthesis

“…Over the last five years, there has been a net increase in the number of dendrimers relying on either TEC or TYC. The two reactions were coupled to several other reactions such as Michael Addition [192], CuAAC [103,193], epoxy opening [194], esterification [192,195,196] and silane chemistry [197,198]. In 2009 and 2010, silane chemistry was used with either Grignard [199] or NaBH 4 [200], demonstrating the sturdiness of the thioether.…”