Method for producing polymer nanofoam

Patent metadata

Field	Value
Publication number	US-10106665-B2
Application number	US-201615262600-A
Country	US
Kind code	B2
Filing date	Sep 12, 2016
Priority date	Nov 10, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A method for producing a polymer nanofoam includes: immersing a polymer material in carbon dioxide at a pressure greater than 5 MPa and a temperature of −30° C. to 40° C. to obtain a carbon dioxide-saturated polymer material, wherein the melt index of the polymer material measured at 230° C. and 3.8 kg is between 0.1 g/10 min and 8.0 g/10 min. Thereafter, the carbon dioxide-saturated polymer material is depressurized to atmospheric pressure, and then the carbon dioxide-saturated polymer material is heated to form the polymer nanofoam.

First claim

What is claimed is:

1. A method for producing a polymer nanofoam, comprising:
immersing a polymer material in carbon dioxide at a pressure greater than 5 MPa and a temperature of −30° C. to 40° C. to obtain a carbon dioxide-saturated polymer material, wherein the polymer material has a melt index (3.8 kg/230° C.) of 0.1-8.0 g/10 min, and a weight-average molecular weight of the polymer material is between 30,000 g/mol and 130,000 g/mol;
depressurizing the carbon dioxide-saturated polymer material to atmospheric pressure; and
heating the carbon dioxide-saturated polymer material to form the polymer nanofoam.

2. The method of claim 1 , wherein an average cell size of the formed polymer nanofoam is between 10 nm and 1000 nm.

3. The method of claim 1 , wherein a cell density of the formed polymer nanofoam is 10 12 cells/cm 3 or more.

4. The method of claim 1 , wherein a relative density of the formed polymer nanofoam is between 0.1 and 0.9.

5. The method of claim 1 , wherein the formed polymer nanofoam is a closed-cell structure, an open-cell structure, or a combination thereof.

6. The method of claim 1 , wherein a pressure during the immersion of the polymer material is larger than 5 MPa and less than 30 MPa.

7. The method of claim 1 , wherein a temperature of heating the carbon dioxide-saturated polymer material is between 0° C. and 115° C.

8. The method of claim 1 , wherein a time of heating the carbon dioxide-saturated polymer material is between 1 second and 300 seconds.

9. The method of claim 1 , wherein the polymer material comprises polymethyl methacrylate (PMMA), polycarbonate (PC), a cyclic olefin copolymer (COC), polysulfone (PSU), polylactic acid (PLA), thermoplastic urethane (TPU), or acrylonitrile-butadiene-styrene (ABS).

Assignees

• Univ Nat Taiwan Science & Technology

Inventors

• Yeh Shu-Kai
• Liao Zong-En
• Chu Chien-Chia

Classifications

• C08J9/20 Primary

  by suspension polymerisation in the presence of the blowing agent · CPC title

• F16L59/028

  Compositions for or methods of fixing a thermally insulating material · CPC title

• C08J9/122 Primary

  Hydrogen, oxygen, CO2, nitrogen or noble gases · CPC title

• C08J2205/044

  Micropores, i.e. average diameter being between 0,1 micrometer and 0,1 millimeter · CPC title

• C08J2205/052

  Closed cells, i.e. more than 50% of the pores are closed · CPC title