Fabrication of Polymeric Nanocellular Structure by Photochemical Foaming Technique

• Project/Area Number: 17H03453
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Reaction engineering/Process system
• Research Institution: Kyoto University
• Principal Investigator: Ohshima Masahiro 京都大学, 工学研究科, 教授 (60185254)
• Co-Investigator(Kenkyū-buntansha): 引間 悠太 京都大学, 工学研究科, 助教 (50721362) ; 吉元 健治 京都大学, 日本－エジプト連携教育研究ユニット, 特定准教授 (00645278)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥13,390,000 (Direct Cost: ¥10,300,000、Indirect Cost: ¥3,090,000); Fiscal Year 2019: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2018: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2017: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
• Keywords: ナノセルラーフォーム / 微細発泡体 / 化学発泡 / 高分子成形加工 / 光反応 / 機能性材料 / 発泡 / ナノセルラー / 光 / 高分子 / 成型加工 / 共重合体 / 成形加工

Outline of Final Research Achievements

TThe aim of this research was to establish a photochemical reaction foaming method: By synthesizing a copolymer having a functional group that generates gas in response to ultraviolet (UV) irradiation and heat, the photochemical reaction foaming method allows us to create a transparent nanocellular polymer foamed film, which has the order of nanometer diameter pores with an ordered structure.
By optimizing the UV irradiation amount, the amount of the photo-acid generator (PAG), the heating temperature and the time, we succeeded to create a foamed plastic film that has ultra-fine bubbles of 100 to 200 nm in diameter with layer structure. The developed process is a simple process cannot need high temperature and high pressure as the conventional process.

Academic Significance and Societal Importance of the Research Achievements

断熱性をもった透明な発泡体が高機能性プラスチック材料として、省エネルギー社会の実現のために求められている。そのなかで、ナノスケールサイズの空隙をもち、高い発泡倍率を有して熱伝導低減効果をもつ部材は、世界的にもいまだ作られていない。世界では、超高圧で、ガスをプラスチック部材に含侵して、減圧により相分離を誘起して、微細空隙構造をもった発泡体を作る方法が検討されているものの、上記の目的を達するものは完成していない。この研究で開発した手法は、簡易であり、かつ従来の化学発泡法の限界を超える手法として位置づけられる。

Research Products

• [Journal Article] Development and Optimization of UV-Induced Chemical Foaming Process (2019)
  • Author(s): Rattanakawin Podchara, Kai Yamamura, Kenji Yoshimoto, Masahiro Ohshima
  • Journal Title: Journal of Photopolymer Science and Technology Volume: 32 Issue: 5 Pages: 693-698
  • DOI: 10.2494/photopolymer.32.693
  • NAID: 130007744451
  • ISSN: 0914-9244, 1349-6336
  • Year and Date: 2019-06-24
  • Peer Reviewed / Open Access
• [Journal Article] Synthesis of Photocleavable Block Copolymers for UV Induced Foaming (2018)
  • Author(s): Rattanakawin Podchara、Fan Weijia、Yamago Shigeru、Yoshimoto Kenji、Ohshima Masahiro
  • Journal Title: Journal of Photopolymer Science and Technology Volume: 31 Issue: 5 Pages: 647-650
  • DOI: 10.2494/photopolymer.31.647
  • NAID: 130007481453
  • ISSN: 0914-9244, 1349-6336
  • Year and Date: 2018-06-25
  • Peer Reviewed / Open Access
• [Presentation] Nanocellular Chemical Foam of Thin Film Using Blowing Agent Embedded Polymers (2019)
  • Author(s): Podchara Rattanakawin, Kenji Yoshimoto, Masahiro Ohshima
  • Organizer: FOAM2019, Society of Plastic Engineers
  • Int'l Joint Research
• [Presentation] 光化学反応による発泡プラスチックの創製 (2018)
  • Author(s): 山村海、Podchara Rattanakawin、吉元健治、大嶋正裕
  • Organizer: プラスチック成形加工学会第29回年次大会
• [Presentation] UV induced chemical foaming of self-assembled block copolymers (2018)
  • Author(s): Podchara Rattanakawin、山村海、Wejja Fan、吉元健治、大嶋正裕、山子茂
  • Organizer: プラスチック成形加工学会第29回年次大会