Compositions comprising low molecular weight polyhydroxyalkanoates and methods employing same

Abstract

Polyhydroxyalkanoate compositions including hot melt adhesive compositions, biodegradable wax compositions, and protective coating compositions are provided and include a low molecular weight polyhydroxyalkanoate, a terminally-modified polyhydroxyalkanoate, or both. The compositions are biodegradable and environmentally friendly. Methods of protecting an article, such as a food product like cheese, are also provided and include coating or encapsulating the article with a composition containing a low molecular weight polyhydroxyalkanoate, a terminally-modified polyhydroxyalkanoate, or both.

1 - 42 . (canceled)  
   
   
       43 . A hot melt adhesive composition comprising: 
 a biodegradable polyhydroxyalkanoate having at least one of the terminal end groups selected from: 
 a) —CO—CH═CR 9 R 10 ;  
 b) —OR 11 ;  
 c) —COOR 12 ;  
 d) —COR 13 ; or  
 e) —O − M +   
 wherein R 9 , R 10 , R 11 , R 12 , or R 13  which are the same or different, represents saturated or unsaturated hydrocarbon radicals, halo- or hydroxy-substituted radicals, hydroxy radicals, nitrogen-substituted radicals, oxygen-substituted radicals, or a hydrogen atom, with the proviso that R  11  is not a hydrogen atom, and M +  is a counterion;  
   optionally comprising at least one tackifying resin; and    optionally comprising at least one wax;    wherein the hot melt adhesive composition has a viscosity of less than about 100,000 centipoise at 150° C.    
   
   
       44 . The hot melt adhesive composition of  claim 43 , wherein one of said terminal end groups is —CO—CH═CR 9 R 10 .  
   
   
       45 . The hot melt adhesive composition of  claim 43 , wherein one of said terminal end groups is —OR 11 .  
   
   
       46 . The hot melt adhesive composition of  claim 43 , wherein one of said terminal end groups is —COOR 12 .  
   
   
       47 . The hot melt adhesive composition of  claim 43 , wherein said polyhydroxyalkanoate has a molecular weight of from about 500 to less than 20,000.  
   
   
       48 . The hot melt adhesive composition of  claim 43 , wherein said polyhydroxyalkanoate has a molecular weight of from about 20,000 to about 1.5 million.  
   
   
       49 . The hot melt adhesive composition of  claim 43 , further comprising at least one reactive monomeric component.  
   
   
       50 . The hot melt adhesive composition of  claim 49 , wherein said reactive monomer is at least one of an epoxy monomer, an acrylate monomer, a methacrylate monomer, a silicone monomer, a siloxane monomer, a urethane monomer, an isocyanate monomer, an anhydride monomer, an oxime, and combinations thereof.  
   
   
       51 . The hot melt adhesive composition of  claim 43 , wherein said at least one tackifying resin is present in said composition.  
   
   
       52 . The hot melt adhesive composition of  claim 43 , wherein said at least one tackifying resin is present in said composition in an amount of up to about 60 wt % based on the total weight of the composition.  
   
   
       53 . The hot melt adhesive composition of  claim 43 , wherein said at least one wax is present in said composition.  
   
   
       54 . The hot melt adhesive composition of  claim 43 , wherein said at least one wax is present in said composition in an amount of up to about 40 wt % based on the total weight of the composition.  
   
   
       55 . The hot melt adhesive composition of  claim 43 , wherein the polyhydroxyalkanoate is a polymer of one or more subunits having the chemical formula:  
       T-[—OCR 1 R 2 (CR 3 R 4 ) n CO-] p -Q  
     wherein n is 0 or an integer up to about 100; p is from about 0 to about 100; R 1 , R 2 , R 3 , and R 4 , which are the same as each other or different from one another, are each independently selected from saturated and unsaturated hydrocarbon radicals, halo- and hydroxy-substituted radicals, hydroxy radicals, halogen radicals, nitrogen-substituted radicals, oxygen-substituted radicals, or hydrogen atoms; T is selected from hydrogen, an alkyl, aryl, alkaryl, or aralkyl group containing from about 1 to about 20 carbon atoms, or an R′″COO carboxylate group wherein R′″ is an aliphatic or aromatic hydrocarbon radical containing from about 1 to about 20 carbon atoms; and Q is selected from: 
 a hydroxy radical or an OR″ radical wherein R″ is a substituted or unsubstituted alkyl, aryl, alkaryl, or aralkyl radical containing from 1 to about 20 carbon atoms;  
 OAOH;  
 OAOOC(CH 2 ) y CHROH;  
 OAO{OC(CH 2 ) y CHRO} x H; or  
 B;  
 wherein each R is independently selected from hydrogen, a saturated alkyl group having from about 1 to about 16 carbon atoms, an unsaturated alkyl group having from about 2 to about 16 carbon atoms, or mixtures thereof; A is (CH 2 ) m  or (CH 2 CHR′O) m , where m is from about 1 to about 50 and R′ is hydrogen or methyl; x is from about 2 to about 50; y is from 0 to about 3; and B is selected from:  
 trimethylol propane when z is 1, 2, 3 or a mixture of 1, 2, and/or 3,  
 glycerol when z is 1, 2, 3 or a mixture of 1, 2, and/or 3,  
 triethanolamine when z is 1, 2, 3 or a mixture of 1, 2, and/or 3, or  
 sucrose when z is 1 to p where p is the number of free hydroxyl groups or derivatives present in said compound, and  
 wherein the number average molecular weight of the compound is at least about 500.  
 
   
   
       56 . The hot melt adhesive composition of  claim 43 , wherein the polyhydroxyalkanoate is selected from poly(hydroxybutyrate), polyhydroxybutyrate-co-hydroxyvalerate, polyhydroxybutyrate-co-4-hydroxybutyrate, polyhydroxybutyrate-co-3-hydroxyhexanoate, polyhydroxybutyrate-co-3-hydroxyheptanoate, or polyhydroxybutyrate-co-3-hydroxyoctanoate.  
   
   
       57 . The hot melt adhesive composition of  claim 43 , wherein the polyhydroxyalkanoate comprises a polymer selected from the group consisting of poly(lactic acid)s, poly(glycolic acid)s, 3-hydroxyacids, 4-hydroxyacids, 5-hydroxyacids, copolymers thereof, and blends thereof.  
   
   
       58 . The hot melt adhesive composition of  claim 43 , wherein the polyhydroxyalkanoate comprises a mixture of thermally depolymerizable polyhydroxyalkanoates.  
   
   
       59 . The hot melt adhesive composition of  claim 43 , further comprising at least one thermally depolymerizable polymer other than polyhydroxyalkanoate.  
   
   
       60 . The hot melt adhesive composition of  claim 49 , wherein the thermally depolymerizable polymer is selected from polycarbonates, polyolefins, polystyrenes, polyacetals, waxes, or combinations thereof.  
   
   
       61 . The hot melt adhesive composition of  claim 43 , wherein the polyhydroxyalkanoate is dissolved in a solvent or a mixture of solvents.  
   
   
       62 . The hot melt adhesive composition of  claim 43 , wherein said hot melt adhesive composition is biodegradable.  
   
   
       63 . The hot melt adhesive composition of  claim 44 , wherein said hot melt adhesive composition is biodegradable.  
   
   
       64 . An article comprising two components adhered together by the hot melt adhesive composition of  claim 43 .  
   
   
       65 . An article comprising two components each having a respective surface, and wherein the respective surfaces of the two components are adhered together with the hot melt adhesive composition of  claim 43 .  
   
   
       66 . A method of adhering two components together comprising: 
 providing two components; and    applying the hot melt adhesive composition of  claim 43  to said two components to adhere said two components together.    
   
   
       67 . A method of adhering two components together comprising: 
 providing two components;    applying the hot melt adhesive composition of  claim 43  to at least one of said two components; and    contacting one of said two components with the other of said two components such that said hot melt adhesive composition is between said two components.    
   
   
       68 . A wax composition comprising a polyhydroxyalkanoate selected from: 
 biodegradable polyhydroxyalkanoates having a molecular weight of from about 500 to less than about 50,000; or    biodegradable polyhydroxyalkanoates having at least one of the terminal end groups selected from: 
 a) —CO—CH═CR 9 R 10 ;  
 b) —OR 11 ;  
 c) —COOR 12 ,  
 d) —COR 13 ; or  
 e) —O − M +   
 wherein R 9 , R 10 , R 11 , R 12 , or R 13  which are the same or different, represents saturated or unsaturated hydrocarbon radicals, halo- or hydroxy-substituted radicals, hydroxy radicals, nitrogen-substituted radicals, oxygen-substituted radicals, or a hydrogen atom, with the proviso that R  11  is not a hydrogen atom, and M +  is a counterion;  
   wherein said wax composition exhibits at least one of the following properties:    a crystalline to microcrystalline structure;    a capacity to acquire gloss when rubbed;    a capacity to produce pastes or gels with suitable solvents or when mixed with other waxes;    a low viscosity at just above the melting point; and    a low solubility in solvents for fats at room temperature.    
   
   
       69 . The wax composition of  claim 68 , further comprising at least one other component selected from paraffin waxes, microcrystalline waxes, high density low molecular weight polyethylene waxes, by-product polyethylene waxes, Fischer-Tropsch waxes, oxidized Fischer-Tropsch waxes, hydroxy stearamide waxes, fatty amide waxes, and combinations thereof.  
   
   
       70 . A film comprising the wax composition of  claim 68 .  
   
   
       71 . An article having a protective coating thereon wherein said protective layer comprises the wax composition of  claim 68 .  
   
   
       72 . An article having a protective coating thereon wherein said protective layer comprises the wax composition of  claim 69 .  
   
   
       73 . The wax composition of  claim 68 , further comprising a pigment or dye.  
   
   
       74 . A food product having a first protective coating on a surface thereof, said protective coating comprising the wax composition of  claim 68 .  
   
   
       75 . The food product of  claim 74 , wherein said food product comprises a cheese product.  
   
   
       76 . The food product of  claim 74 , further comprising a second protective coating on a surface of said first protective coating, said second protective coating comprising a wax composition of  claim 68  that differs from said first protective coating.  
   
   
       77 . The food product of  claim 76 , wherein said second protective coating comprises a polyhydroxyalkanoate having a number average molecular weight that is less than the number average molecular weight of the polyhydroxyalkanoate of said first protective coating.  
   
   
       78 . A method of protecting a food product, comprising applying to a surface of said food product a protective coating comprising the wax composition of  claim 68 .  
   
   
       79 . The method of  claim 78 , wherein said food product is a cheese product.  
   
   
       80 . The method of  claim 78 , comprising encapsulating said food product in said protective coating.  
   
   
       81 . An alkanoic acid ester oligomer having a number average molecular weight of greater than about 1000 and having a formula selected from:  
       R′{OCHR(CH 2 ) n CO} m OCH 2 CH 2 OR′  (VII)  
     wherein R represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, R′ represents a hydrogen atom or an acetate group, n is from about 1 to about 3, and m is from about 1 to about 3;  
       R′{OCHR(CH 2 ) n CO} m OCH 2 CH(CH 3 )OR′  (VIII)  
     wherein R′ is a hydrogen atom or an acetate group, n is from about 1 to about 3, and m is from about 1 to about 3; or  
       R′{OCHR(CH 2 ) n CO} m OR″  (IX)  
     wherein R represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, R′ represents a hydrogen atom or an acetate group, R″ represents a hydrogen atom or an alkyl group having from about 1 to about 10 carbon atoms, n is from about 1 to about 3, m is from about 1 to about 3, and said oligomer has the following Hansen solubility parameters: 
 dispersive—from about 16 to about 22,  
 polar—from about 3 to about 12, and  
 hydrogen—from about 6 to about 17.  
 
   
   
       82 . A solution comprising a solute dissolved in or mixed with an alkanoic acid ester oligomer of  claim 81 .  
   
   
       83 . The solution of  claim 82 , wherein said alkanoic acid ester monomer comprises an alkanoic acid ester monomer of formula (VII).  
   
   
       84 . The solution of  claim 82 , wherein said alkanoic acid ester monomer comprises an alkanoic acid ester monomer of formula (VIII).  
   
   
       85 . The solution of  claim 82 , wherein said alkanoic acid ester monomer comprises an alkanoic acid ester monomer of formula (IX).  
   
   
       86 . An alkanoic acid ester oligomer having a number average molecular weight of greater than about 1000 and having one or more of the following formulae:  
       R′(OCHR′CH 2 ) p  {OCHR(CH 2 ) n CO} m OR″  (X)  
     wherein R represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, R′ represents a hydrogen atom or an acetate group, R″ is a hydrogen atom or and alkyl group having from about 1 to about 18 carbon atoms; n is from about 1 to about 3, m is from about 1 to about 30, and p is from about 1 to about 100;  
       R′{OCHR(CH 2 ) n CO} m OCH 2 CHR″) q OR″  (XI)  
     wherein R represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, R′ is a hydrogen atom or an acetate group, R″ represents a hydrogen atom or a methyl group, n is from about 1 to about 3, and m is from about 1 to about 30, and q is from about 1 to about 100; or  
       R′(OCHR′CH 2 ) p {OCHR(CH 2 ) n CO} m (OCH 2 CHR″) q OR″  (XII)  
     wherein R represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, R′ represents a hydrogen atom or a methyl group, R″ represents a hydrogen atom or an alkyl group having from about 1 to about 18 carbon atoms, n is from about 1 to about 3, m is from about 1 to about 30, p is from about 1 to about 100, and q is from about 1 to about 100.  
   
   
       87 . A liquid mixture or solution comprising a surface active agent, said surface active agent comprising an alkanoic acid ester oligomer of  claim 86 .  
   
   
       88 . The liquid mixture or solution of  claim 87 , wherein said alkanoic acid ester monomer has the formula (X).  
   
   
       89 . The liquid mixture or solution of  claim 87 , wherein said alkanoic acid ester monomer has the formula (XI).  
   
   
       90 . The liquid mixture or solution of  claim 87 , wherein said alkanoic acid ester monomer has the formula (XII).