Thermoplastic elastomer compositions having biorenewable content

Abstract

Thermoplastic elastomer compositions, in particular derived from one or more styrenic block copolymers wherein at least one styrenic block copolymer comprises a controlled distribution copolymer block including a conjugated diene and a mono alkenyl arene, a plurality of biorenewable materials, preferably a softener and one or more synergistic additives such as a polar polymer; a synergistic block copolymer such as a relatively high molecular weight styrenic block copolymer; and/or filler. Numerous desirable articles can be formed from the compositions. Processes for preparing the compositions and articles are disclosed.

1 . A thermoplastic elastomer composition, comprising:
 a styrenic block copolymer comprising at least one controlled distribution copolymer block having a conjugated diene and a mono alkenyl arena;   a biorenewable softener comprising a natural ester; and   at least one synergistic additive comprising one or more of starch, thermoplastic starch, a biorenewable polar polymer, and a high molecular weight styrenic block copolymer.   
     
     
         2 . The composition according to  claim 1 , wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 5 to 90 parts by weight, wherein the natural ester is an ester-containing oil which is present in an amount from 1 to 85 parts by weight, and wherein the composition further includes a polyolefin, wherein all said parts are based on 100 parts by weight of the composition. 
     
     
         3 . The composition according to  claim 2 , wherein the biorenewable polar polymer is present in an amount from about 2 to about 60 parts by weight, and wherein the composition is free of mineral oil. 
     
     
         4 . The composition according to  claim 2 , wherein the composition further includes a functionalized styrenic block copolymer. 
     
     
         5 . The composition according to  claim 2 , wherein the composition includes one or more of the starch and the thermoplastic starch in an amount from 2 parts to 80 parts by weight. 
     
     
         6 . The composition according to  claim 2 , wherein the biorenewable polar polymer is present in an amount from about 2 parts to about 60 parts by weight, wherein the ester-containing oil is present in an amount from about 10 parts to about 65 parts by weight, and wherein the composition is free of a mineral oil. 
     
     
         7 . The composition according to  claim 1 , wherein the composition includes the high molecular weight styrenic block copolymer in an amount from about 1 parts to about 30 parts by weight per 100 parts by weight of the composition, and wherein the composition further includes a polyolefin. 
     
     
         8 . The composition according to  claim 1 , wherein the biorenewable polar polymer is present in an amount from 1 to 80 parts by weight, wherein the natural ester is an ester-containing oil which is present in an amount from 1 to 85 parts by weight, wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 10 to 70 parts by weight, wherein all said parts are based on 100 parts by the weight of the composition. 
     
     
         9 . The composition according to  claim 8 , wherein the biorenewable polar polymer is one or more of a polylactic acid, polylactide, poly(glycolic acid), polyglycolide, poly(lactic-co-glycolic), poly(lactide-co-glycolide), polyglyconate, poly(hydroxyalkanoate), polyorthoester, polycaprolactone, polydioxanone, polyanhydride, and polyether-block-amide. 
     
     
         10 . The composition according to  claim 9 , wherein the composition further includes a polyolefin, and wherein the composition further includes the high molecular weight styrenic block copolymer. 
     
     
         11 . The composition according to  claim 2 , wherein the ester-containing oil comprises hydrogenated oil. 
     
     
         12 . The composition according to  claim 3 , wherein the high molecular weight styrenic block copolymer is present in an amount from about 2 to about 20 parts by weight, wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 20 to 35 parts by weight, wherein the biorenewable polymer is present in an amount from 2 to 20 parts by weight, and wherein the ester-containing oil is present in an amount from 10 to 65 parts by weight. 
     
     
         13 . The composition according to  claim 5 , wherein the one or more of the starch and thermoplastic starch are present in an amount from 2 to 40 parts by weight, wherein a dispersion aid is present wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 15 to 70 parts by weight, wherein the ester-containing oil is present in an amount from 10 to 65 parts by weight, and wherein the composition further includes a functionalized styrenic block copolymer. 
     
     
         14 . A thermoplastic elastomer composition, comprising:
 a styrenic block copolymer comprising at least one controlled distribution copolymer block having a conjugated diene and a mono alkenyl arene;   a biorenewable softener comprising an ester-containing oil; and   one or more of starch and thermoplastic starch in an amount from about 2 parts to about 80 parts by weight, wherein all parts are based on 100 parts by weight of the composition.   
     
     
         15 . The composition according to  claim 14 , wherein a dispersion aid is present in an amount from about 1 to about 80 parts by weight based on 100 total parts by weight of starch and thermoplastic starch, and wherein a polyolefin is also present. 
     
     
         16 . The composition according to  claim 14 , wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 5 to 90 parts by weight, wherein the ester-containing oil is present in an amount from about 5 to about 75 parts by weight and wherein the composition further includes a functionalized styrenic block copolymer. 
     
     
         17 . The composition according to  claim 14 , wherein the styrenic block copolymer having the controlled distribution copolymer block is present in an amount from 20 to 35 parts by weight, wherein the ester-containing oil is present in an amount from 10 to 65 parts by weight, and wherein the one or more of starch and thermoplastic starch is present in an amount from 2 to 40 parts by weight. 
     
     
         18 . The composition according to  claim 17 , wherein the composition further includes a functionalized styrenic block copolymer. 
     
     
         19 . An article comprising the composition according to  claim 1 . 
     
     
         20 . A process for preparing a thermoplastic elastomer composition, comprising the step of combining the components set forth in  claim 14 , utilizing a one step compounding process.