Method of making and using shape memory polymer composite patches

Abstract

A method of repairing a composite component having a damaged area including: laying a composite patch over the damaged area; activating the shape memory polymer resin to easily and quickly mold said patch to said damaged area; deactivating said shape memory polymer so that said composite patch retains the molded shape; and bonding said composite patch to said damaged part.

1 . A product comprising: A multi-layer thermo-reversible dry adhesive comprising: a first layer comprising a soft dry adhesive; a second layer comprising a shape memory polymer; wherein the thermo-reversible dry adhesive has a first shape at a first temperature and a second shape at a second temperature with a load applied. 
   
   
       2 . A product as set forth in  claim 1  wherein the shape memory polymer comprises: at least one of a rigid epoxy or a flexible epoxy; and at least one of a crosslinking agent or a catalytic curing agent; wherein the rigid epoxy is an aromatic epoxy having at least two epoxide groups, the flexible epoxy is an aliphatic epoxy having at least two epoxide groups, and the crosslinking agent is one of a multi-amine, an organic multi-carboxylic acid, or an anhydride. 
   
   
       3 . A product as set forth in  claim 1 , wherein the soft dry adhesive comprises: at least one of a rigid epoxy or a flexible epoxy; and at least one of a crosslinking agent or a catalytic curing agent;
 wherein the rigid epoxy is an aromatic epoxy having at least two epoxide groups, the flexible epoxy is an aliphatic epoxy having at least two epoxide groups, and the crosslinking agent is one of a multi-amine, an organic multi-carboxylic acid, or an anhydride.   
   
   
       4 . A product as set forth in  claim 1  further comprising a substrate wherein the multilayer thermo-reversible dry adhesive is positioned on top of the substrate with the first layer in contact with the at least one substrate. 
   
   
       5 . A product as set forth in  claim 4  wherein the pull-off force of the multilayer thermo-reversible dry adhesive with the curved structure is about 0 to 50 N/cm2 for one of the at least one substrate. 
   
   
       6 . A product as set forth in  claim 4  wherein the pull-off force of the multilayer thermo-reversible dry adhesive with the relatively flat structure is about 10 to about 200 N/cm2 for one of the at least one substrate. 
   
   
       7 . A method comprising: forming a multilayer thermo-reversible dry adhesive comprising: forming a first layer by curing a first component, a second component and a third component; forming a second layer over the first layer comprising pouring a mixture of a fourth component and a fifth component over the first layer and curing the second layer; and post-curing the first and second layers to form a multi-layer thermo-reversible adhesive having a curved structure at a first temperature and having a relatively flat structure at a second temperature with a load applied. 
   
   
       8 . A method as set forth in  claim 7  wherein the first component, the second component and the third component comprises: at least one of a rigid epoxy or a flexible epoxy; and at least one of a crosslinking agent or a catalytic curing agent; wherein the rigid epoxy is an aromatic epoxy having at least two epoxide groups, the flexible epoxy is an aliphatic epoxy having at least two epoxide groups, and the crosslinking agent is one of a multi-amine, an organic multi-carboxylic acid, or an anhydride. 
   
   
       9 . A method as set forth in  claim 7  wherein the first component, the second component and the third component comprise an aromatic diepoxy, an aliphatic diepoxy, and a diamine. 
   
   
       10 . A method as set forth in  claim 9  wherein the aromatic epoxy is diglycidyl ether of bisphenol A epoxy monomer with an approximate epoxy equivalent weight of 180. 
   
   
       11 . A method as set forth in  claim 9  wherein the aliphatic epoxy is NGDE. 
   
   
       12 . A method as set forth in  claim 9  wherein the diamine is polypropylene glycol)bis (2-aminopropyl)ether with an average molecular weight of 230. 
   
   
       13 . A method as set forth in  claim 7  wherein the fourth component and the fifth component comprise an aliphatic diepoxy and a diamine, and wherein the components are present in an amount sufficient to provide, upon curing of the second layer, a soft epoxy dry adhesive layer having a glass transition temperature of −90° C. to 200° C. and having a pull-off strength of 1-200 N/cm 2 . 
   
   
       14 . A method comprising: providing a multilayer thermo-reversible dry adhesive comprising at least one dry adhesive layer and at least one shape memory polymer layer; heating the multilayer thermo-reversible dry adhesive to a temperature higher than the glass transition temperature of the shape memory polymer; imposing a load on the multilayer thermo-reversible dry adhesive while cooling to a temperature below the glass transition temperature of the shape memory polymer, so that the multilayer thermo-reversible dry adhesive forms a strong adhesive bond to an underlying substrate and; releasing the multilayer thermo-reversible dry adhesive from the substrate by heating the multilayer thermo-reversible dry adhesive to a temperature above the glass transition temperature of the shape memory polymer. 
   
   
       15 . A method as set forth in  claim 14  wherein the load is about 1 N/cm 2  to about 20 N/cm 2 . 
   
   
       16 . A method as set forth in  claim 14  wherein the glass transition temperature of the shape memory polymer is about 25 to about 200° C. 
   
   
       17 . A method as set forth in  claim 14  wherein the glass transition temperature of the dry adhesive is about −90 to about 200° C. 
   
   
       18 . A method as set forth in  claim 14  wherein the underlying substrate comprises one of stainless steel, glass, aluminum alloy 5657, polypropylene, or Teflon.