Biodegradable nanopolymer compositions and biodegradable articles made thereof

Abstract

Biodegradable nanopolymer compositions and methods of making the compositions are provided. In a general embodiment, the present disclosure provides a biodegradable nanopolymer composition made from starting material comprising poly(lactic acid), co-polyester polymer with adipic acid compounded and nanoparticles of a mineral material such as silica and magnesium silicate. In addition, the present disclosure provides processes for making the biodegradable nanopolymer compositions as well as biodegradable articles made using the biodegradable nanopolymer compositions such as molded, formed and extruded articles.

1 . A composition made from starting materials comprising: 
 between about 20% and about 97% by weight of poly(lactic acid) polymer (PLA) on the basis of the total weight of the polymer composition;    between about 0.5% and about 65% by weight of a co-polyester polymer with adipic acid on the basis of the total weight of the polymer composition;    nanoparticles of a mineral material selected from the group consisting of silica, nanoclays of the vermiculite family, magnesium silicate and combinations thereof; and    organic peroxide.    
     
     
         2 . The composition of  claim 1 , wherein the nanoparticles comprise between about 0.01% and about 6% by weight on the basis of the total weight of the polymer composition.  
     
     
         3 . The composition of  claim 1 , wherein the organic peroxide comprises between about 0.01% and about 5% by weight on the basis of the total weight of the polymer composition.  
     
     
         4 . The composition of  claim 1 , wherein the nanoparticles of the mineral material have a size ranging between about 20 and about 500 nanometers.  
     
     
         5 . The composition of  claim 1 , wherein the nanoparticles of the mineral material have a degree of purity of at least 99.9%.  
     
     
         6 . The composition of  claim 5 , wherein the degree of purity is 99.99%.  
     
     
         7 . The composition of  claim 1  comprising between about 5% and about 35% of calcium sulfate.  
     
     
         8 . The composition of  claim 1  comprising organically coated calcium carbonate.  
     
     
         9 . The composition of  claim 1  comprising an oligomeric chain extender.  
     
     
         10 . The composition of  claim 9 , wherein the oligomeric chain extender is selected from the group consisting of styrene-acrylic copolymers, oligomers containing glycidyl groups incorporated as side chains and combinations thereof.  
     
     
         11 . The composition of  claim 1  comprising between about 1% and about 32% of particles of a mineral filler selected from the group consisting of magnesium silicate, talc and combinations thereof, the mineral filler having a particle size ranging between about 0.2 and about 4.0 microns.  
     
     
         12 . The composition of  claim 1 , wherein the organic peroxide is selected from the group consisting of diacetyl peroxide, cumyl-hydro-peroxide, dibenzoyl peroxide, dialkyl peroxide, 2,5-methyl-2,5-di(terbutylperoxy)-hexane and combinations thereof.  
     
     
         13 . The composition of  claim 1 , wherein the co-polyester polymer is selected from the group consisting of polyester, co-polyester and combinations thereof.  
     
     
         14 . A molded, extruded or thermoformed article comprising: 
 a biodegradable composition made from starting materials comprising between about 20% and about 97% by weight of poly(lactic acid) polymer, between about 0.5% and about 65% by weight of co-polyester polymer with adipic acid, between about 0.01% and about 6% by weight of nanoparticles of a mineral material selected from the group consisting of silica, nanoclays of the vermiculite family, magnesium silicate and combinations thereof, and between about 0.01% and about 5% by weight of organic peroxide, each on the basis of the total weight of the biodegradable composition.    
     
     
         15 . The article of  claim 14 , wherein the nanoparticles of the mineral material have a size comprised between about 20 and about 500 nanometers.  
     
     
         16 . The article of  claim 14 , wherein the nanoparticles of the mineral material have a degree of purity of at least 99.9%.  
     
     
         17 . The article of  claim 16 , wherein the degree of purity is 99.99%.  
     
     
         18 . The article of  claim 14 , wherein the biodegradable composition comprises between about 5% and about 35% of calcium sulfate.  
     
     
         19 . The article of  claim 14 , wherein the biodegradable composition comprises organically coated calcium carbonate.  
     
     
         20 . The article of  claim 14 , wherein the biodegradable composition comprises an oligomeric chain extender.  
     
     
         21 . The article of  claim 14 , wherein the article is selected from the group consisting of utensils, food service-ware, forks, spoons, knives, chopsticks, containers, cups, plates, pots and combinations thereof.  
     
     
         22 . The article of  claim 14  comprising particles of a mineral filler selected from the group consisting of magnesium silicate, talc and combinations thereof, the mineral filler having a particle size between about 0.2 and about 4.0 microns.  
     
     
         23 . A method of producing an article comprising a biodegradable composition, the method comprising: 
 (i) providing between about 20% and about 97% by weight of poly(lactic acid) polymer, between about 0.5% and about 65% by weight of co-polyester polymer with adipic acid, between about 0.01% and about 6% by weight of nanoparticles of a mineral material selected from the group consisting of silica, nanoclays of the vermiculite family, magnesium silicate and combinations thereof, and between about 0.01% and about 5% by weight of organic peroxide, each on the basis of the total weight of the biodegradable composition;    (ii) mixing the constituents of (i) so as to prevent the creation of aggregates;    (iii) heating the mixture to a temperature ranging from about 95° C. to about 135° C.; and    (iv) forming the heated mixture to obtain a desired shape of the article.    
     
     
         24 . The method of  claim 23 , wherein the nanoparticles of the mineral material are indirectly introduced into a barrel of a mixer/extruder.  
     
     
         25 . The method of  claim 23 , wherein the nanoparticles of the mineral material are introduced into a barrel of a mixer/extruder through a side feeder.  
     
     
         26 . The method of  claim 23 , wherein the nanoparticles of the mineral material have a size ranging between about 20 and about 500 nanometers.  
     
     
         27 . The method of  claim 23 , wherein the nanoparticles of the mineral material have a degree of purity of at least 99.9%.  
     
     
         28 . The method of  claim 27 , wherein the degree of purity is at least 99.99%.  
     
     
         29 . The method of  claim 23  comprising adding in step i) between about 5% and about 35% of calcium sulfate.  
     
     
         30 . The method of  claim 23  comprising adding in step i) organically coated calcium carbonate.  
     
     
         31 . The method of  claim 23  comprising adding in step i) an oligomeric chain extender.  
     
     
         32 . The method of  claim 23  comprising adding in step i) between about 1% and about 32% of particles of a mineral filler selected from the group consisting of magnesium silicate, talc and combinations thereof, the mineral filler having a particle size ranging between about 0.2 and about 4.0 microns.  
     
     
         33 . The method of  claim 23 , wherein forming the heated mixture includes subjecting the biodegradable composition to a process selected from the group consisting of injection molding, profile extrusion, thermoform extrusion and combinations thereof.