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WO2009038567A1 - Copolymères stables - Google Patents

Copolymères stables Download PDF

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Publication number
WO2009038567A1
WO2009038567A1 PCT/US2007/020507 US2007020507W WO2009038567A1 WO 2009038567 A1 WO2009038567 A1 WO 2009038567A1 US 2007020507 W US2007020507 W US 2007020507W WO 2009038567 A1 WO2009038567 A1 WO 2009038567A1
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WO
WIPO (PCT)
Prior art keywords
poly
solution
autoclaving
free radical
stable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2007/020507
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English (en)
Inventor
Lev Bromberg
Elmer C. Lupton
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B L Partnership
Original Assignee
B L Partnership
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Filing date
Publication date
Application filed by B L Partnership filed Critical B L Partnership
Priority to PCT/US2007/020507 priority Critical patent/WO2009038567A1/fr
Publication of WO2009038567A1 publication Critical patent/WO2009038567A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
    • C08F283/06—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
    • C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
    • C08J3/075—Macromolecular gels
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • C08L51/006—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to block copolymers containing at least one sequence of polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2351/00—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers

Definitions

  • the present invention relates to graft reverse thermal copolymer solutions which show enhanced stability.
  • the present invention further relates to water soluble graft reverse thermal copolymer solids which can be used to manufacture the graft reverse thermal copolymer solutions.
  • the present invention further relates to the use of these graft reverse thermal copolymer solutions in medical and pharmaceutical applications and in other areas.
  • PAA segments are grafted onto a polyether backbone (typically represented by a PEO-PPO-PEO copolymer) via C-C bonding. It is believed that he PEO-PPO-PEO copolymers act as chain transfer agents in polymerization of acrylic acid, when hydrogen abstraction from these polyethers is allowed. The transfer to propagating polymer in acrylic emulsion polymerization is known to be often substantial and leading to a gelled polymer.
  • the copolymers of PAA and polyethers resulting from the novel synthetic route possess micelle-forming capability and have been used in topical drug delivery, pharmaceuticals, and consumer products [Ron, E.
  • Polymers Polyoxyethylene-b-polyoxypropylene-b-polyoxyethylene-g-polyfacrylic acid) Polymers (Smart HydrogelTM) as a Carrier in Controlled Delivery of Proteins and Peptides, Proc. Polym. Mater. Sci. Eng. 1997, 76, 276; Bromberg, L. E., Orkisz, M. J., Ron, E. S. Bioadhesive Properties of Polyoxyethylene-b-polyoxypropylene-b-polyoxyethylene-g-poly(acrylic acid) Polymers (Smart HydrogelTM), Polym. Prepr. 1997, 38, 626; Bromberg, L. E., Ron, E. S.
  • the polymer formed from grafting the branched polyelectrolyte poly(sodium acrylate) (PAA) to the surface-active triblock copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b- poly(ethylene oxide) (PEO-PPO-PEO) represents a class of unique new materials that undergo reversible gelation in semidilute (1 wt % and below) aqueous solutions over a narrow temperature range.1-11
  • the covalent grafting via C-C bonding results in high molecular weight (above 105 Da) PEO-PPO-PEO-g-PAA polymers with regular short-chain branching" and in Huibers et. al.
  • the invention is solution of a graft reverse thermal hydrogel, which solution, when measured at a temperature T t ⁇ ms i t i on + ⁇ T where ⁇ T is between 0 and 20 degrees C, displays a complex viscosity after autoclaving which is not degraded to a large extent from its complex viscosity prior to autoclaving.
  • the invention is the solid graft reverse thermal copolymer which, when dissolved in aqueous solution, will display a complex viscosity after autoclaving, when measured at a temperature Transition + ⁇ T where ⁇ T is between 0 and 20 degrees C, which is not degraded to a large extent from its complex vi scos ity prior to autoclaving.
  • the invention is a solution of a graft reverse thermal hydrogel, which solution, when measured at a temperature Tra ns i t i on + ⁇ T where ⁇ T is between 0 and 20 degrees C, displays a complex viscosity after aging for one year at 25 degrees C which is not degraded to a large extent from its complex viscosity prior to aging.
  • the invention is the use of the solution of a graft reverse thermal hydrogel, which retains its complex viscosity after autoclaving or aging, for medical or pharmaceutical applications or for cosmetic applications.
  • graft reverse thermal copolymer to mean the materials taught by patents 5,939,485, 6.316.011 and similar copolymers manufactured by grafting a polyionic component onto a thermally responsive component during the process of free radical synthesis of the poly- ionic component.
  • graft reverse thermal hydrogel to mean the aqueous solution of a graft reverse thermal copolymer which displays the property of increasing substantially in complex viscosity upon a relatively small change in solution temperature.
  • the hydrogel In order to meet our definition of graft reverse thermal copolymer and and graft reverse thermal hydrogel, the hydrogel must display the property of increasing substantially in complex viscosity upon a relatively small change in solution temperature.
  • a graft reverse thermal hydrogel and/or graft reverse thermal copolymer may lose its ability to display a substantially increased complex viscosity upon a relatively small change in solution temperature.
  • This material would still fit our definition of graft reverse thermal hydrogel and graft reverse thermal copolymer during the period of time that it displayed the property of substantially increasing its complex viscosity upon a relatively small change in solution temperature.
  • a medical or pharmaceutical application to mean an application where the material or materials are used to achieve or to attempt to achieve a medical or pharmaceutical objective including a veterinary, dental or botanical or other such plant health related objective.
  • Such an application would include but not be limited to the medical or pharmaceutical applications taught in L.E. Bromberg, E.C. Lupton, M.E. Schiller, MJ. Timm, G. McKinney , "Responsive Polymer Networks and Methods of their Use", U.S. Pat. 5,939,485, August 17, 1999; L.E. Bromberg, E.C. Lupton Jr., M.E. Schiller, M.J. Timm, G. W. McKinney III, M. Orkisz, B.
  • Schiller teaches the use of a crosslinked gel to achieve the medical or pharmaceutical objective; one type of embodiment of our invention uses the materials taught here to achieve the medical or pharmaceutical objective outlined by Schiller
  • a cosmetic application to mean an application where the material or materials are used to achieve or to attempt to achieve a cosmetic objective.
  • a cosmetic application would include but not be limited to the cosmetic applications taught in L. E. Bromberg, E.C. Lupton, M.E. Schiller, MJ. Timm, G. McKinney , "Responsive Polymer Networks and Methods of their Use", U.S. Pat. 5,939,485, August 17, 1999; L.E. Bromberg, E.C. Lupton Jr., M.E. Schiller, M.J. Timm, G. W. McKinney III, M. Orkisz, B.
  • Schiller teaches the use of a crosslinked gel to achieve the cosmetic objective; one type of embodiment of our invention uses the materials taught here to achieve the cosmetic objective outlined by Schiller
  • Fig 1. is a series of viscosity temperature curves of a graft reverse thermal hydrogel before autoclaving and after one, two and three autoclave cycles. This material shows thermal degradation to a large extent.
  • Figure 2 is a series of viscosity-temperature curves of a graft reverse thermal hydrogel before autoclaving and after one, two and three autoclave cycles. This is the material of the invention and does not show thermal degradation to a large extent.
  • Fig 3 shows a drawing of the structure of the graft reverse thermal hydrogel above and below the transition temperature.
  • Fig. 4 shows another example of the instability of the prior art graft reverse thermal hydrogel.
  • Ammonium persulfate or peroxides such as lauroyl peroxide, benzoyl pe ⁇
  • the peroxy -0-0- bond in APS is analogous to the one in organic peroxides. APS is a relatively
  • the sulfate radical then attacks the monomer (acrylic acid) causing its polymerization, or, if a
  • polyether is present in the reaction system, it may cause hydrogen abstraction.
  • the very nature of the synthesis of Pluronic-PAA resulting in large amounts of poly ether-radicals can cause instability of the copolymers in the presence of atmospheric oxygen.
  • Degradation of polyethers in the presence of air at elevated temperatures has been described [Yang, Li; Heatley, Frank; Blease, Trevor G.; Thompson, Robert I. G. Eur. Polym. J. 1996, 52(5), 535-547] (This reference is explicitly incorporated herein by reference.) and was shown to cause the loss of molecular weight.
  • significant structural changes were the formation of formate ester and hydroxy end-groups, the former predominating.
  • the amount of O 2 incorporation is not a simple function of aging time or temperature and is often dictated by trace impurities and catalysts. For instance, it may be generally affected by the presence of quinones and the like customarily added to the monomer for stability. The disappearance of the ether hydroperoxides via free radical decomposition leading to new radical initiation will create the remainder of the secondary degradation species CH 3 CH 3
  • reaction 8 It can be postulated that in simple polyethers, mechanism for formation of ketones and alcohols is a bimolecular termination reaction of ether-peroxy radicals (eq 8). Tertiary per- oxy radicals cannot undergo bimolecular termination via this mechanism; alternative multistep mechanisms still produce alcohols and ketones for tertiary radicals. If the termination shown in eq 8 were the only reaction, the concentration of ketones and alcohols would be equal. Chain scission via a cyclic peroxide intermediate can also be a mechanism for the formation of ketones. Alkoxy radicals, formed from a homolysis reaction of the corresponding hydroperoxides, may also yield secondary alcohols (eq 9a) or aldehydes (eq 9b). A variety of different mechanisms for the production of alcohols and ketones can be suggested for the oxidation of polyethers.
  • Pluronic F 127 NF was obtained from BASF Corp. (Parsippany, NJ) and used without further treatment. Acrylic acid (99%) was purchased from Aldrich Chemical Co. (Milwaukee, WI) and was vacuum-distilled prior to the use. Dodecane (98%) and ammonium persulfate (99+%) were obtained from Aldrich and used as received. Poly(vinylpyrrolidinone-co-l- hexadecene) (Ganex V-216) (dispersion stabilizer) was obtained from International Specialty Products (Wayne, NJ) and used without further treatment. All other chemicals, gases and organic solvents of the highest purity available were obtained from commercial sources. Synthesis
  • Poly(ethylene oxide)-6-poly(propylene oxide)-6-(polyethylene oxide)-g-poly(acrylic acid) (CAS #186810-81- 1) was synthesized by dispersion/emulsion polymerization of acrylic acid as follows: Acrylic acid (40 g) in a 125-mL flask was partially neutralized by addition of 50 w/w% aqueous NaOH solution while stirring. The degree of neutralization of acrylic acid was 6 mol%. Upon redissolu- tion of the formed precipitate, Pluronic (35 g) was charged into the flask and allowed to completely dissolve in acrylic acid under constant stirring.
  • a 500-mL multinecked, thermostatted flanged glass reactor equipped with a mechanical stirrer, syringe sampler, thermometer, programmable heater bath, and a gas inlet/outlet was charged with 400 mL of 1 w/v% Ganex solution in dodecane and was deoxygenated for 2 h by nitrogen flow while stirring.
  • the reactor was heated up to 70 0 C at 2 °C/min under constant nitrogen flow and was kept at this temperature for 1 h under stirring. Then the reactor was allowed to equilibrate at 20 0 C, the nitrogen flow was discontinued and the slurry of the resulting polymer was filtered off on air using Whatman filter paper (retention 10 ⁇ m). The polymer was repeatedly washed with excess hexane in separation funnels. The resultant white powder was dried in a rotor evaporator at 40 0 C for 24 h and dissolved in DI water at room temperature under stirring and constant purging of the forming solution by gentle air bubbling. The pH was adjusted to 7.0 by 5M NaOH solution. The process of dissolution took about 4 days. The polymer resulting from the above synthetic procedure is termed "unstabilized" Pluronic-PAA. Characterization Procedures
  • transition range to mean the temperature range within which the primary substantial increase in complex viscosity is occurring.
  • the transition range occurs from 27 degrees C to about 40 degrees C.
  • it occurs from about 22 degrees C to about 39 degrees C.
  • it can be more difficult to identify the upper end of the transition range because the complex viscosity of the material continues.
  • there clearly is a break in the curve and a change in the slope of the viscosity- temperature curve. This break in the curve and change in the slope identifies the upper end of the viscosity-temperature curve.
  • transition temperature Transition
  • transition temperature to mean the midpoint of the transition range. Since in figure 1 , the transition range is from about 27 degrees C to about 40 degrees C, the transition temperature would be about 33.5 degrees C. Since in figure 2 the transition range is from about 22 degrees C to about 39 degrees C, the transition temperature is about 30.5 degrees C. In some cases, it has been observed for the graft reverse thermal hydrogels of the prior art that after autoclaving or after aging, in addition to the dimution or loss of complex viscosity in response to temperature increase, the transition range and transition temperature are shifted.
  • Chart 1 Retention of complex viscosity at the transition temperature for a graft reverse thermal hydrogel of the prior art
  • the solution becomes so degraded by autoclaving or by aging that no measurable change in viscosity is seen upon temperature increase and no transition range and transition temperature can be determined.
  • the same transition temperature should be used after autoclaving or aging as before autoclaving or aging
  • Acrylic acid (40 g) in a 125-mL flask was partially neutralized by addition of 50 w/w% aqueous NaOH solution while stirring. The degree of neutralization of acrylic acid was 6 mol%.
  • Pluronic (35 g) was charged into the flask and allowed to completely dissolve in acrylic acid under constant stirring.
  • a glass reactor as in Example 1 was charged with 400 mL of 0.2 w/v% Ganex solution in dodecane and was deoxygenated overnight by nitrogen flow while stirring.
  • Freshly prepared 300 mg/mL aqueous ammonium persulfate solution (2 mL) was added into the solution of Pluronic in acrylic acid under stirring.
  • the reactor was heated up to 70 0 C at 2 °C/min under constant nitrogen flow and was kept at this temperature for 2 h under stirring. Then the reactor was allowed to equilibrate at 20 0 C, the nitrogen flow was discontinued and the slurry was transferred to the separation funnel with excess hexane under nitrogen blanket.
  • the polymer powder was then dried under vacuum (1 mTorr) at 4O 0 C overnight and the dry powder was kept at -7O 0 C.
  • the Pluronic-PAA powder was then dissolved in deaerated 0.1 M NaOH solution at 4 0 C while bubbling nitrogen through the solution.
  • the resulting 10 w/v% solution was snap-frozen in liquid nitrogen and lyophilized for 48 h at 1-5 mTorr using a VirTis Freezemobile freeze dryer.
  • the resulting fluffy powder was quickly dissolved in DI water at 2 w/v% and pH was adjusted to 7.0.
  • the solutions were tested Theologically as described in Example 1. Results
  • Graft Reverse Thermal Hydrogel (poly(ethylene oxide) -b-poly (propylene oxide) -b- poly(ethylene oxide) -g-poly (acrylic acid) ) which is stabilized to degradation by aging
  • the graft reverse thermal hydrogel of Example II is allowed to age for one year at 25 degrees C. Measurement of the complex viscosity at a temperature TtransMo n + ⁇ T where ⁇ T is between 0 and 20 degrees C shows that the complex viscosity is 90% of greater of the complex viscosity measured prior to aging.
  • Acrylic acid (99%), lauroyl peroxide (97%), benzoyl peroxide (97%), dodecane (99+%), 2,2'- azobisisobutyronitrile (98%, AIBN), and 2,2,6,6,-tetramethyl-l- ⁇ i ⁇ eridinyloxy (99%, TEMPO) were purchased from Aldrich Chemical Co. (Milwaukee, WI) and used as received.
  • Initiators 2,2'-azobis(2,4-dimethylpentanenitrile) (Vazo 52) and lj'-azobiscyclohexanecarbonitrile (Vazo 88) were obtained from DuPont Specialty Chemicals (Wilmington, DE) and were recrystallized from cold acetone.
  • Poly(vinylpyrrolidinone-co-l-hexadecene) (Ganex V-216) (dispersion stabilizer) was obtained from International Specialty Products (Wayne, NJ) and used as received. All other chemicals, gases, and organic solvents of the highest purity available were obtained from commercial sources.
  • Synthesis was carried out on a laboratory scale in an adiabatic mode.
  • Poly(ethylene oxide)-b-poly(propylene oxide)-b-(poly(ethylene oxide))-g-poly(acrylic acid) was synthesized by dispersion/emulsion polymerization of acrylic acid along with simultaneous grafting of poly (aery Hc acid) onto Pluronic backbone as follows: Acrylic acid in a 125-mL flask was partially neutralized by the addition of 50 w/w % aqueous NaOH solution while stirring. The degree of neutralization of acrylic acid was 6 mol %. Upon redissolution of the formed precipitate, Pluronic was charged into the flask and allowed to completely dissolve in acrylic acid under constant agitation.
  • a 500-mL multinecked, thermostated flanged glass reactor equipped with a mechanical stirrer, syringe sampler, thermometer, programmable heater bath, and a gas inlet/outlet was charged with 400 mL of Ganex solution in dodecane and was deoxyge- nated overnight by nitrogen flow while stirring. The rate of stirring and the ratio of the impeller diameter to the diameter of the vessel allowed for turbulence and micromixing.
  • Initiator system comprising a solution of peroxide and/or azo compound in a small amount of acrylic acid was added into the solution of Pluronic in acrylic acid under stirring. The resulting solution was deoxygenated by nitrogen flow for 1 h and introduced into the reactor under nitrogen blanket while stirring.
  • the polymer was repeatedly washed with excess heptane and then with excess hexane in separation funnels.
  • the resultant white powder was dried under vacuum (10 "3 Torr) at 40 0 C for 24 h. After filtration using filter paper and washing by heptane and hexane the polymer was exposed to air.
  • the polymer thus synthesized was dissolved in DI water, in the presence of air, for about a week and the pH was adjusted to 7.0 by 5M NaOH solution.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)

Abstract

L'invention porte sur un hydrogel à tenue thermique, inversé, greffé, qui ne présente pas de perte substantielle de viscosité complexe à et jusqu'à 20 degrés au-dessus de la température de transition lors d'un passage à l'autoclave ou d'un vieillissement. D'autres modes de réalisation comprennent le copolymère à tenue thermique, inversé, greffé, qui peut être dissous dans de l'eau pour produire l'hydrogel à tenue thermique, inversé, greffé, un procédé de fabrication du copolymère à tenue thermique, inversé, greffé, et des applications pour l'hydrogel à tenue thermique, inversé, greffé, stable.
PCT/US2007/020507 2007-09-21 2007-09-21 Copolymères stables Ceased WO2009038567A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2007/020507 WO2009038567A1 (fr) 2007-09-21 2007-09-21 Copolymères stables

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2007/020507 WO2009038567A1 (fr) 2007-09-21 2007-09-21 Copolymères stables

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WO2009038567A1 true WO2009038567A1 (fr) 2009-03-26

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5939485A (en) * 1995-06-19 1999-08-17 Medlogic Global Corporation Responsive polymer networks and methods of their use
US20050235852A1 (en) * 2002-10-31 2005-10-27 Agfa-Gevaert N.V. Process for the offset printing of functional patterns
US20060036043A1 (en) * 2002-12-09 2006-02-16 Basf Aktiengesellschaft Method for the production of low-odor hydrogel-forming polymers

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5939485A (en) * 1995-06-19 1999-08-17 Medlogic Global Corporation Responsive polymer networks and methods of their use
US20050235852A1 (en) * 2002-10-31 2005-10-27 Agfa-Gevaert N.V. Process for the offset printing of functional patterns
US20060036043A1 (en) * 2002-12-09 2006-02-16 Basf Aktiengesellschaft Method for the production of low-odor hydrogel-forming polymers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"FRIED. Polymer science and technology.", 1995, PRENTICE-HALL PTR, UPPER SADDLE RIVER, NJ, ISBN: 013685561-X, pages: 32 - 33 *

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