WCA November 2020

only by di-functional acrylic monomer but also by urethane acrylate oligomer. The dynamic mechanical analyses suggested the presence of a separated phase for the films with enhanced tensile strength by bimodal tanδ curves. However, bimodal tanδ curves alone could not define phase separation status. In this work, AFM was applied in order to confirm the detail about phase separation of soft coating films for optical fibre. As a result, we found that AFM was suitable for visualisation of the morphologies of phase separate films with low Young’s modulus. As a next step, we are going to examine the Run2 film and elucidate the mechanism that Run2 film had similar mechanical strength as Run5 film in spite of lower Young’s modulus. 4 References [1] M. Mori, Z. Komiya, T. Ukachi, Radtech ’98 North America UV/EB Conference Proceedings, 328 (1998).

Courtesy of IWCS Cable & Connectivity Symposium, Charlotte, North Carolina, USA, September/October 2019.

Figure 3 shows an AFM phase image of modulus and adhesion maps of the Run5 film. The characteristic phase separated morphologies consisting of bright and dark nanophasic domains were observed in both maps. Bright domains (higher modulus domains) in modulus maps corresponded with dark domains (lower adhesion domains). This result yields that it is assumed that these domains were composed of rigid polyurethane and acrylate sequences. On the contrary, dark domains (lower modulus domains) in modulus maps corresponded with bright domains (higher adhesion domains). It is assumed that these domains were composed of flexible polyether segments. 3 Conclusions It was found that the tensile strength of low modulus UV curable urethane acrylate resin was greatly affected not ❍ ❍ Figure 3 : AFM phase images (Run5). Upper figure: modulus map, lower figure: adhesion map

Tsukuba Laboratories, JSR Corporation 25 Miyukigaoka, Tsukuba, Ibaraki, 305-0841 Japan Tel : +81 29 856 1218 Email : kunpei_kobayashi@jsr.co.jp Website : www.jsr.co.jp

53

www.read-wca.com

Wire & Cable ASIA – November/December 2020