Polylactic acid (PLA) with low moisture vapor transmission rates by grafting through of hydrophobic polymers directly to PLA backbone

Patent metadata

Field	Value
Publication number	US-9725548-B2
Application number	US-201615257513-A
Country	US
Kind code	B2
Filing date	Sep 6, 2016
Priority date	Oct 21, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Polylactic acid-backbone graft and bottlebrush copolymers with low moisture vapor transmission rates are synthesized by polymerizing a lactide-functionalized hydrophobic macromonomer using ring-opening polymerization (ROP). In some embodiments of the present invention, the macromonomer is a lactide-functionalized hydrophobic polymer that may be synthesized by, for example, polymerizing a hydrophobic monomer (e.g., a fluorinated vinyl monomer such as 2,2,2-trifluroethyl methacrylate) capable of undergoing radical polymerization (e.g., styrenic, vinylic, acrylic, etc.) using a brominated lactide initiator via atom transfer radical polymerization (ATRP). The brominated lactide initiator may be 3-bromo-3,6-dimethyl-1,4-dioxane-2,5-dione prepared by, for example, reacting lactide with N-bromosuccinimide in the presence of benzoyl peroxide.

First claim

What is claimed is:

1. A polylactic acid-backbone graft copolymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein HY is a phenyl group functionalized with a fluorine-containing moiety or C(O)OR′, wherein R′ is an alkyl group having one or more carbon atoms functionalized with a fluorine-containing moiety, wherein the variables x, y, z, and n each denotes a degree of polymerization of a respective repeating unit, wherein the value of the variable n is greater than 1, and wherein the value of the variables x, y, and z each is equal to or greater than 1.

2. A polylactic acid-backbone bottlebrush copolymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein HY is a phenyl group functionalized with a fluorine-containing moiety or C(O)OR′, wherein R′ is an alkyl group having one or more carbon atoms functionalized with a fluorine-containing moiety, wherein the variables x and n each denotes a degree of polymerization of a respective repeating unit, and wherein the value of the variables x and n each is greater than 1.

3. A polylactic acid-backbone copolymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein HY is a phenyl group functionalized with a fluorine-containing moiety or C(O)OR′, wherein R′ is an alkyl group having one or more carbon atoms functionalized with a fluorine-containing moiety, wherein the variables x, y, z and n each denotes a degree of polymerization of a respective repeating unit, wherein the value of the variable n is greater than 1, wherein the value of the variable x is either equal to zero or equal to or greater than 1, and wherein the value of the variables y and z each is equal to or greater than 1.

4. The polylactic acid-backbone copolymer as recited in claim 3 , wherein the polylactic acid-backbone copolymer is synthesized by polymerizing a lactide-functionalized hydrophobic macromonomer alone or with lactide using ring-opening polymerization (ROP), wherein the lactide-functionalized hydrophobic macromonomer is a lactide-functionalized hydrophobic polymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein HY is a phenyl group functionalized with a fluorine-containing moiety or C(O)OR′, wherein R′ is an alkyl group having one or more carbon atoms functionalized with a fluorine-containing moiety, wherein the variable n denotes a degree of polymerization of a repeating unit, and wherein the value of the variable n is sufficient to provide the lactide-functionalized hydrophobic polymer with a number-average molecular weight M n between about 1000 and about 10,000.

5. The polylactic acid-backbone copolymer as recited in claim 3 , wherein the polylactic acid-backbone copolymer is a polylactic acid-backbone bottlebrush copolymer having the following formula:

wherein the variables x and n each denotes a degree of polymerization of a respective repeating unit, and wherein the value of the variables x and n each is greater than 1.

6. The polylactic acid-backbone copolymer as recited in claim 5 , wherein the polylactic acid-backbone bottlebrush copolymer is synthesized by polymerizing 3-poly(2,2,2-trifluoroethyl methacrylate)-3,6-dimethyl-1,4-dioxane-2,5-dione alone using ring-opening polymerization (ROP).

7. The polylactic acid-backbone copolymer as recited in claim 3 , wherein the polylactic acid-backbone copolymer is a polylactic acid-backbone graft copolymer having the following formula:

wherein the variables x, y, z and n each denotes a degree of polymerization of a respective repeating unit, wherein the value of the variable n is greater than 1, and wherein the value of the variables x, y and z each is equal to or greater than 1.

8. The polylactic acid-backbone copolymer as recited in claim 7 , wherein the polylactic acid-backbone graft copolymer is synthesized by polymerizing 3-poly(2,2,2-trifluoroethyl methacrylate)-3,6-dimethyl-1,4-dioxane-2,5-dione and lactide using ring-opening polymerization (ROP).

Assignees

• IBM

Inventors

• Boday Dylan J
• Mauldin Timothy C

Classifications

• C08G63/91

  Polymers modified by chemical after-treatment · CPC title

• C08G63/08

  Lactones or lactides · CPC title

• C08F220/22

  Esters containing halogen · CPC title

• C08F293/005 Primary

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C08F214/18

  Monomers containing fluorine · CPC title