Method for in-situ synthesis of silicon nanoparticles

Patent metadata

Field	Value
Publication number	US-9617396-B2
Application number	US-201314379677-A
Country	US
Kind code	B2
Filing date	Feb 20, 2013
Priority date	Feb 22, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

The invention relates to a method for in-situ synthesis of silicon nanoparticles in a thermosetting polymeric matrix, the thermosetting and thermoset matrices obtained in this way and a material including same. The method includes the following steps: a) forming an aqueous-phase/organic-phase inverse emulsion, wherein the aqueous phase includes at least a basic catalyst and the organic phase includes at least a non-cross-linked (co)polymer precursor chosen from an aliphatic, cycloaliphatic or aromatic epoxy resin precursor, a polyester-imide precursor, an unsaturated/epoxy polyester (co)polymer precursor, a polyether/epoxy (co)polymer precursor and a polyurethane precursor; b) introducing, into the inverse emulsion formed in step a), at least one silicon precursor forming a complete network whereof the rate of hydrolysis is greater than the cross-linking speed of the (co)polymer and c) stirring the mixture obtained in step b) and heating to a temperature between 20° C. and 70° C.

First claim

The invention claimed is:

1. A method for in-situ synthesis of silica nanoparticles in a thermosetting polymer matrix,
wherein the method comprises the following steps:
a) forming an aqueous phase-organic phase inverted emulsion, in which the aqueous phase comprises at least one basic catalyst and the organic phase comprises at least one noncrosslinked (co)polymer precursor selected from a precursor of aliphatic, cycloaliphatic or aromatic epoxy resin, a polyester-imide precursor, a precursor of unsaturated polyester/epoxy (co)polymer, a precursor of polyether/epoxy (co)polymer and a polyurethane precursor;
b) introducing at least one silica precursor into the inverted emulsion formed in step a) forming a complete network whose rate of hydrolysis is greater than the rate of crosslinking of the (co)polymer and
c) stirring the mixture obtained in step b) and heating to a temperature between 20° C. and 70° C., and wherein no step of functionalization of the polymer precursor is carried out and no solvent or coupling agent is added.

2. The method as claimed in claim 1 , wherein the basic catalyst is selected from ammonia or urea.

3. The method as claimed in claim 1 , wherein the silica precursor forming a complete network is selected from the group consisting of tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetrakis(2,2,2-trifluoroethoxy)silane and tetrakis(1,1,1,3,3,3-hexafluoropropoxy)silane.

4. The method as claimed in claim 1 , characterized in that the precursor is a precursor of polyether/epoxy (co)polymer or a precursor of polyester-imide polymer and in that steps a) and b) are carried out in a double-wall reactor with temperature controlled at 20° C. and step c) is carried out at 70° C.

5. The method as claimed in claim 1 , wherein the ratio of the weight of silica precursor to the weight of (co)polymer precursor is between 1/100 and 35/100.

6. The method as claimed in claim 1 , wherein in step a) the noncrosslinked (co)polymer precursor does not contain hardener and in that it comprises a step of adding hardener to the mixture obtained after step c).

7. The method as claimed in claim 6 , wherein the hardener is a hardener based on acid anhydride.

8. The method as claimed in claim 6 , wherein the hardener is selected from the group consisting of methylhexahydrophthalic anhydride (MHHPA), methyltetrahydrophthalic anhydride (MTHPA), phthalic anhydride (PA), tetrahydrophthalic anhydride (THPA), and hexahydrophthalic anhydride (HHPA).

9. The method as claimed in claim 1 wherein the ratio of the weight of silica precursor to the weight of (co)polymer precursor 9/100.

10. A method for synthesis of a thermoset polymer matrix doped with silica nanoparticles comprising the following steps:
a1) carrying out the method as claimed in claim 1 ,
b1) heating the thermosetting matrix doped with silica nanoparticles obtained in step a1) to the temperature of hardening of the polymer matrix.

11. A method for in-situ synthesis of silica nanoparticles in a thermosetting polymer matrix, wherein the method comprises the following steps:
a) forming an aqueous phase-organic phase inverted emulsion, in which the aqueous phase comprises at least one basic catalyst and the organic phase comprises at least one noncrosslinked (co)polymer precursor selected from a precursor of aliphatic, cycloaliphatic or aromatic epoxy resin, a polyester-imide precursor, a precursor of unsaturated polyester/epoxy (co)polymer, a precursor of polyether/epoxy (co)polymer and a polyurethane precursor;
b) introducing at least one silica precursor into the inverted emulsion formed in step a) forming a complete network whose rate of hydrolysis is greater than the rate of crosslinking of the (co)polymer and
c) stirring the mixture obtained in step b) and heating to a temperature between 20° C. and 70° C.,
and wherein in step a) the noncrosslinked (co)polymer precursor does not contain hardener, and wherein the method comprises a step of adding a hardener to the mixture obtained after step c).

12. The method as claimed in claim 11 , wherein no step of functionalization of the polymer precursor is carried out and no solvent or coupling agent is added.

13. The method as claimed in claim 11 , wherein the basic catalyst is selected from ammonia or urea.

14. The method as claimed in claim 11 , wherein the silica precursor forming a complete network is selected from the group consisting of tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetrakis(2,2,2-trifluoroethoxy)silane and tetrakis(1,1,1,3,3,3-hexafluoropropoxy)silane.

15. The method as claimed in claim 11 , characterized in that the precursor is a precursor of polyether/epoxy (co)polymer or a precursor of polyester-imide polymer and in that steps a) and b) are carried out in a double-wall reactor with temperature controlled at 20° C. and step c) is carried out at 70° C.

16. The method as claimed in claim 11 , wherein the ratio of the weight of silica precursor to the weight of (co)polymer precursor is between 1/100 and 35/100.

17. The method as claimed in claim 11 , wherein the hardener is a hardener based on acid anhydride.

18. A method for synthesis of a thermoset polymer matrix doped with silica nanoparticles comprising the following steps:
a1) carrying out the method as claimed in claim 11 ,
b1) heating the thermosetting matrix doped with silica nanoparticles obtained in step a1) to the temperature of hardening of the polymer matrix.

19. The method as claimed in claim 11 , wherein the hardener is selected from the group consisting of methylhexahydrophthalic anhydride (MHHPA), methyltetrahydrophthalic anhydride (MTHPA), phthalic anhydride (PA), tetrahydrophthalic anhydride (THPA), and hexahydrophthalic anhydride (HHPA).

20. The method as claimed in claim 11 , wherein the ratio of the weight of silica precursor to the weight of (co)polymer precursor 9/100.

Assignees

• Commissariat Energie Atomique

Inventors

• Schubert Chloé
• Poncelet Olivier

Classifications

• C08K3/36

  Silica · CPC title

• C08J3/215 Primary

  at least one additive being also premixed with a liquid phase · CPC title

• H01B3/40

  epoxy resins · CPC title

• C08J2300/24

  Thermosetting resins · CPC title

• H01B3/302

  Polyurethanes or polythiourethanes; Polyurea or polythiourea · CPC title