Versatile, facile and scalable route to polylactic acid-backbone graft and bottlebrush copolymers

Patent metadata

Field	Value
Publication number	US-9228044-B2
Application number	US-201414243191-A
Country	US
Kind code	B2
Filing date	Apr 2, 2014
Priority date	Apr 2, 2014
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

Polylactic acid-backbone graft and bottlebrush copolymers are synthesized by polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP). In some embodiments of the present invention, the macromonomer is a lactide-functionalized polymer that may be synthesized by, for example, polymerizing a monomer 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 method for synthesizing a polylactic acid-backbone bottlebrush or graft copolymer, comprising:
polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP), wherein the lactide-functionalized macromonomer is a lactide-functionalized polymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein R′ is a phenyl group, C(O)OR″, wherein R″ is an alkyl group having one or more carbon atoms, wherein the variable n denotes a degree of polymerization of a repeating unit, wherein the value of the variable n is sufficient to provide the lactide-functionalized polymer with a number-average molecular weight M n between about 1000 and about 10,000, wherein the lactide-functionalized macromonomer is 3-poly(styrene)-3,6-dimethyl-1,4-dioxane-2,5-dione.

2. The method as recited in claim 1 , wherein the step of polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP) includes polymerizing the 3-poly(styrene)-3,6-dimethyl-1,4-dioxane-2,5-dione alone to produce a polylactic acid-backbone bottlebrush copolymer having the following formula:

wherein variables x and n each denotes a degree of polymerization of a respective repeating unit, wherein the value of the variable n is sufficient to provide the repeating unit associated with the variable x with a number-average molecular weight M n between about 1000 and about 10,000, and wherein x is greater than 1.

3. The method as recited in claim 1 , wherein the step of polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP) includes polymerizing the 3-poly(styrene)-3,6-dimethyl-1,4-dioxane-2,5-dione and lactide to produce a polylactic acid-backbone graft copolymer having the following formula:

wherein 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 sufficient to provide the repeating unit associated with the variable y with a number-average molecular weight M n between about 1000 and about 10,000, and wherein x, y, and z are equal to 1 or greater.

4. A method for synthesizing a polylactic acid-backbone bottlebrush or graft copolymer, comprising:
polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP), wherein the lactide-functionalized macromonomer is a lactide-functionalized polymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein R′ is a phenyl group, C(O)OR″, wherein R″ is an alkyl group having one or more carbon atoms, wherein the variable n denotes a degree of polymerization of a repeating unit, wherein the value of the variable n is sufficient to provide the lactide-functionalized polymer with a number-average molecular weight M n between about 1000 and about 10,000, wherein the step of polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP) includes the steps of:
preparing a catalyst/initiator solution comprising a catalyst, an initiator and an organic solvent;
adding the catalyst/initiator solution to a reaction vessel;
removing at least some of the organic solvent from the catalyst/initiator solution in the reaction vessel;
adding the lactide-functionalized macromonomer to the reaction vessel;
heating the reaction vessel.

5. The method as recited in claim 4 , wherein the catalyst is Sn(Oct) 2 .

6. The method as recited in claim 5 , wherein the initiator is benzyl alcohol.

7. The method as recited in claim 6 , wherein the organic solvent is anhydrous toluene.

8. The method as recited in claim 7 , wherein the step of heating the reaction vessel includes the step of heating the reaction vessel to at least 120° C.

9. A method for synthesizing a polylactic acid-backbone bottlebrush or graft copolymer, comprising:
polymerizing a lactide-functionalized macromonomer using ring opening polymerization (ROP), wherein the lactide-functionalized macromonomer is a lactide-functionalized polymer represented by the following formula:

wherein R is a hydrogen atom or a methyl group, and wherein R′ is a phenyl group, C(O)OR″, wherein R″ is an alkyl group having one or more carbon atoms, wherein the variable n denotes a degree of polymerization of a repeating unit, wherein the value of the variable n is sufficient to provide the lactide-functionalized polymer with a number-average molecular weight M n between about 1000 and about 10,000;
heating the polylactic acid-backbone bottlebrush or graft copolymer to produce phase separation of polymeric components of the copolymer.

Assignees

• IBM

Inventors

• Boday Dylan J
• Mauldin Timothy C

Classifications

• C08G63/08 Primary

  Lactones or lactides · CPC title

• C08F257/02 Primary

  on to polymers of styrene or alkyl-substituted styrenes · CPC title

• C08G63/91

  Polymers modified by chemical after-treatment · CPC title

• C08F2438/01

  Atom Transfer Radical Polymerization [ATRP] or reverse ATRP · CPC title