Ultra-micro-cellular foaming using super critical CO_2

超临界CO_2超微孔发泡

• 批准号: 12650751
• 负责人: OHSHIMA Masahiro
• 金额: $ 2.43万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650751/
• 关键词: Plastic Foam; Micro-cellular foam; CO_2; Bubble nucleation; Bubble growth; Visual observation; Nano-composite; Foaming; 高分子成形加工; ポリプロピレン; 核生成; 気泡; ポリオレフィン; マイクロセルラー; 二酸化炭素; マイクロセルラープラスチック; 発泡; 超臨界流体

The visual observation of physical foaming processes is conducted to understand the bubble nucleation and bubble growth behavior in polymers and to develop the technique of micro cellular plastic foams, whose bubble size less than 1 micron meter and bubble density is larger than 10^9 bubbles per cm^3.The visual observation elucidates that to make the bubble size smaller. the bubble nucleation should be enhanced by increasing the foaming agent concentration, making pressure release rate fester, and/or reducing the surface tension of the polymer and the bubble growth rate should be reduced by depressing the mass transfer of foaming agents from polymer matrix to bubbles. The viscosity is a less important factor during the bubble growth process but it becomes an important factor in the process of coalescence and bubble stabilization and break-up. Controlling the temperature of the foaming process and carefully selecting the polymer, the transparent foams of polyolefin foams were created, where the bubble size is less than 1-micron meter. However, because of the low foaming rate, any appropriate applications of the created foams were not found at this stage unless the foaming rote is increased. Nano-composites, which is a composite of polypropylene and clay, were foamed. The effect of clay on nucleation was investigated and orientation of clay around the bubble was also investigated in order to make the mechanical strength of the foam higher.

为了解聚合物中气泡的成核和长大行为，发展泡径小于1 μ m、泡密度大于10^9个/cm ^3的微孔塑料泡沫技术，对物理发泡过程进行了可视化观察。应通过增加发泡剂浓度、使压力释放速率加快和/或降低聚合物的表面张力来增强气泡成核，并应通过抑制发泡剂从聚合物基质到气泡的质量传递来降低气泡生长速率。粘度在气泡生长过程中是一个次要因素，但在气泡的聚并、稳定和破裂过程中却成为一个重要因素。控制发泡过程的温度并仔细选择聚合物，产生聚烯烃泡沫的透明泡沫，其中气泡尺寸小于1微米。然而，由于低发泡速率，在该阶段没有发现所产生的泡沫的任何适当的应用，除非发泡速率增加。将聚丙烯和粘土复合而成的纳米复合材料进行发泡。研究了粘土对成核的影响，并研究了粘土在气泡周围的取向，以提高泡沫的机械强度。

项目成果

K.Taki, T.Nakayama, T.Yatsuzuka, M.Ohshima: "Visual Observation of Batch and Continuous Foaming Processes"Cellular Plastics. (In print). (2003)

K.Taki、T.Nakayama、T.Yatsuzuka、M.Ohshima：“间歇和连续发泡过程的目视观察”多孔塑料。

M.Okamoto, P.H.Nam, P.Maiti, T.Kotaka, T.Nakayama, M.Takada, M.Ohshima, A.Usuki, N.Hasegawa, H.Okamoto: "Biaxial-axial flow-induced alignment of silicate layers in polypropylene/clay nanocomposite foam"Nano letters. 1・9. 503-505 (2001)

M.Okamoto、P.H.Nam、P.Maiti、T.Kotaka、T.Nakayama、M.Takada、M.Ohshima、A.Usuki、N.Hasekawa、H.Okamoto：“双轴流诱导的硅酸盐层排列聚丙烯/粘土纳米复合泡沫”Nano letter. 1・9. 503-505 (2001)

M. Okamoto, P. H. Nam, P. Maiti, T. Kotaka, T. Nakayama, M. Takada, M. Ohshima, A. Usuki, N. Hasegawa, H. Okamoto: "Biaxial-axial flow-induced alignment of silicate layers in polypropylene/clay nanocomposite foam"Nano letters. vol.1, No.9. 503-505 (2001)

M. Okamoto、P. H. Nam、P. Maiti、T. Kotaka、T. Nakayama、M. Takada、M. Ohshima、A. Usuki、N. Hasekawa、H. Okamoto：“硅酸盐层的双轴流诱导排列

M. Ohshima: "Polymeric foaming in the 21^<st> century"Proc. of Thai-Japan Polymer Processing Workshop, Bangkok, March. 36-44 (2001)

M. Ohshima：“21世纪的聚合物发泡”Proc。

M.Ohshima: "Polymeric foaming in the 21^<st> century"Proc. of Thai-Japan Polymer Processing Workshop. 36-44 (2001)

M.Ohshima：“21世纪的聚合物发泡”Proc。