Water stable fibers and articles comprising starch, and methods of making the same

Abstract

Water stable fibers and articles made therefrom are formed from a thermoplastic composition comprising destructured starch, polyhydric alcohol, acid, and optionally triglyceride. Processes for making water stable compositions may comprise melt extruding a mixture of destructured starch, polyhydric alcohol, acid, and optionally triglyceride, to form an extrudate, and heating the mixture, extrudate, or both to provide a water stable article.

1 . A fiber comprising a thermoplastic starch composition, said composition comprising:
 a. destructured starch; and   b. ester condensation products formed from a reactant mixture comprising:
 i. polyhydric alcohol having alcohol functional groups; and 
 ii. acid with at least one functional group selected from the group consisting of: 
 carboxylic acid; carboxylic acid anhydride; and combinations thereof; 
   said functional groups being present in said reactant mixture in a molar ratio of said alcohol functional groups to said at least one acid functional group of from about 1:1 to about 200:1;   
       wherein said fiber is Water Stable. 
     
     
         2 . The fiber of  claim 1 , said composition further comprising transesterification products formed from a reactant mixture comprising: polyhydric alcohol and triglyceride. 
     
     
         3 . The fiber of  claim 1 , wherein said acid is selected from the group consisting of: monoacid; diacid; polyacid; polymer comprising at least one acid moiety; co-polymer comprising at least one acid moiety; anhydrides thereof; and combinations thereof. 
     
     
         4 . The fiber of  claim 3 , wherein said acid is selected from the group consisting of: adipic acid; sebatic acid; lauric acid; stearic acid; myristic acid; palmitic acid; oleic acid; linoleic acid; sebacic acid; citric acid; oxalic acid; malonic acid; succinic acid; glutaric acid; maleic acid; fumaric acid; phthalic acid; isophthalic acid; terphthalic acid; acrylic acid; polyacrylic acid; ethylene acrylic acid copolymers; methacrylic acid; itaconic acid; glycidyl methacrylate; and combinations thereof. 
     
     
         5 . The fiber of  claim 3 , wherein said acid is selected from the group consisting of: maleic acid anhydride; phthalic acid anhydride; succinic acid anhydride; and combinations thereof. 
     
     
         6 . The fiber of  claim 1 , wherein said polyhydric alcohol is selected from the group consisting of: glycerol; glycol; sugar; sugar alcohol; and combinations thereof. 
     
     
         7 . The fiber of  claim 1 , wherein said thermoplastic composition further comprises additional polymer selected from the group consisting of: polyhydroxyalkanoate; polyvinyl alcohol; polyethylene; polypropylene; maleated polyethylene; maleated polypropylene; polyethylene terephthalate; polylactic acid; modified polypropylene; nylon; caprolactone; and combinations thereof. 
     
     
         8 . The fiber of  claim 1 , wherein said fiber is biodegradable. 
     
     
         9 . The fiber of  claim 8 , wherein said thermoplastic composition further comprises an additional polymer selected from the group consisting of: polyvinyl alcohol; ester polycondensates; aliphatic/aromatic polyesters; and combinations thereof. 
     
     
         10 . The fiber of  claim 9 , wherein said polymers are selected from the group consisting of: polybutylene succinate; polybutylene succinate co-adipate; co-polyesters of butylene diol, adipic acid, terephtalic acid, and combinations thereof; and combinations thereof. 
     
     
         11 . The fiber of  claim 1 , wherein said fiber is selected from the group consisting of monocomponent fibers; multicomponent fibers; multiconstituent fibers; and combinations thereof. 
     
     
         12 . The fiber of  claim 11 , wherein said fiber is a multicomponent fiber having a sheath and a core, said core comprising said thermoplastic starch composition. 
     
     
         13 . The fiber of  claim 11 , wherein said sheath comprises polymers selected from the group consisting of: polyethylene terephthalate; polyethylene; polypropylene; polyhydroxyalkanoate; polylactic acid; polyester; and combinations thereof. 
     
     
         14 . The fiber of  claim 11 , wherein said fiber is a multicomponent fiber having an islands-in-the-sea configuration, wherein said islands comprise said thermoplastic starch composition. 
     
     
         15 . A nonwoven fabric comprising the fiber of  claim 1 . 
     
     
         16 . A personal hygiene article comprising the fiber of  claim 1 . 
     
     
         17 . An absorbent article comprising the fiber of  claim 1 .