Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Nitrogen-containing reactant
Reexamination Certificate
1999-11-05
2001-08-07
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Nitrogen-containing reactant
C528S487000, C528S489000, C524S839000
Reexamination Certificate
active
06271340
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention concerns the preparation of polymers with low polydispersity and/or controlled molecular weight and architecture by the use of living free radical polymerization initiated by an alkoxyamine or an appropriate nitroxide-initiator combination. It also concerns novel compounds usefull in such polymerizations and methods for their preparation.
Living radical polymerization based on the use of alkoxyamine initiators was invented by Rizzardo et al and is described in U.S. Pat. No. 4,581,429. Recent publications by Georges et al (Trends Polym. Sci., 1994, 2, 66-72), Hawker (J. Am. Chem. Soc., 1994, 116, 11185-11186) and others have described the application of the methodology to the synthesis of narrow polydispersity polystyrenes. The nitroxide component in these latter studies is most often 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or one of its derivatives. We have now discovered the advantages of nitroxide-mediated living free-radical polymerizations employing imidazoline nitroxides (1) as further defined hereafter:
The characteristics of a living polymerization are discussed by Quirk and Lee (
Polymer International
27, 359 (1992)) who give the following experimentally observable criteria:
1. Polymerization proceeds until all of the monomer has been consumed. Further addition of monomer results in continued polymerization.
2. The number average molecular weight (or the number average degree of polymerization) is a linear function of conversion.
3. The number of polymer molecules (and active centers) is a constant which is sensibly independent of conversion.
4. The molecular weight can be controlled by the stoichiometry of the reaction.
5. Narrow molecular weight distribution polymers are produced.
6. Block copolymers can be prepared by sequential monomer addition.
7. Chain end-functionalized polymers can be prepared in quantitative yield.
SUMMARY OF THE INVENTION
This invention provides a polymer of the Formula (2) below:
wherein:
R, R
1
, R
2
, R
3
are each independently selected from the group consisting of C
1
to C
18
alkyl, substituted C
1
to C
18
alkyl, C
6
to C
18
aryl, C
6
to C
18
substituted aryl; R groups that are in a geminal position with respect to each other can together form a 4-8 membered ring; R groups that are in a cis position with respect to each other can together form a 4-8 membered ring;
X is selected from the group consisting of hydrogen, C
1
to C
18
alkyl, substituted C
1
to C
18
alkyl, C
6
to C
18
aryl, C
6
to C
18
substituted aryl; acyl; X and R can form a 5-8 membered ring; X and R
3
can form a 5-8 membered ring;
M is one or more monomer units selected from the group consisting of styrene, substituted styrene, alkyl acrylate, alkyl methacrylate, substituted alkyl acrylate, substituted alkyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide,
N,N-dialkylacrylamide, N,N-dialkylmethacrylamide, isoprene and butadiene;
n is an integer greater than 1;
Y is a residue derived from a species that initiates free radical polymerization or is selected from the group consisting of C
1
to C
18
alkyl, substituted C
1
to C
18
alkyl, C
1
to C
18
alkoxy, substituted Cto C
18
alkoxy, C
6
to C
18
aryl, C
6
to C
18
substituted aryl. C
6
to C
18
aroyloxy, C
6
to C
18
substituted aroyloxy, (C
1
to C
18
alkoxy)carbonyloxy, (C
6
to C
18
aryloxy)carbonyloxy, and sulfate radical anions;
and
all substituents are independently selected from the group that consists of epoxy, hydroxy, C
1
to C
18
alkoxy, acyl, acyloxy, alkoxycarbonyl, aryloxycarbonyl, cyano, silyl, halo, and C
1
to C
18
dialkylamino.
The polymers of this invention have low polydispersity which provide improved flow properties in melt or solution. In addition, the presence of the nitroxyl end-group allows the formation of block copolymers by heating the preformed polymer with a different monomer. Alternatively, the nitroxyl end-group can be reduced or chemically modified to give a polymer with a more desirable end-group. The term “polymer(s)” employed herein includes block and graft copolymers and other complex architectures.
Specific monomers or comonomers from which M is derivable include the following:
methyl methacrylate, ethyl methacrylate, propyl methacrylate (all isomers), butyl methacrylate (all isomers), 2-ethylhexyl methacrylate, isobomyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, alpha-methylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (all isomers), butyl acrylate (all isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile, styrene, functional methacrylates, acrylates and styrenes selected from glycidyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate (all isomers), hydroxybutyl methacrylate (all isomers), N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, triethyleneglycol methacrylate, itaconic anhydride, itaconic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate (all isomers), hydroxybutyl acrylate (all isomers), N,N-dimethylaminoethyl acrylate, N,N-diethylaminoethyl acrylate, triethyleneglycol acrylate, methacrylarnide, N-methylacrylamide, N,N-dimethylacrylamide, N-tert-butylmethacrylamide, N-n-butylmethacrylarnide, N-methylolmethacrylamide, N-ethylolmethacrylamide, N-tert-butylacrylamide, N-n-butylacrylamide, N-methylolacrylamide, N-ethylolacrylamide, vinyl benzoic acid (all isomers), diethylaminostyrene (all isomers), alpha-methylvinyl benzoic acid (all isomers), diethylamino alpha-methylstyrene (all isomers). p-vinylbenzene sulfonic acid, p-vinylbenzene sulfonic sodium salt, trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, tributoxysilylpropyl methacrylate, dimethoxymethylsilylpropyl methacrylate, diethoxymethylsilylpropyl methacrylate, dibutoxymethylsilylpropyl methacrylate, diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropyl methacrylate, diethoxysilyLpropyl methacrylate, dibutoxysilyipropyl methacrylate, diisopropoxysilylpropyl methacrylate, trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, tributoxysilylpropyl acrylate, dimethoxymethylsilylpropyl acrylate, diethoxymethylsilylpropyl acrylate, dibutoxymethylsilylpropyl acrylate, diisopropoxymethylsilylpropyl acrylate, dimethoxysilylpropyl acrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate, diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide, N-burylmaleimide, butadiene, isoprene, chloroprene.
This invention provides a process for preparing the polymers of Formula (2) comprising contacting reactant (i) with one or both of reactants (ii) and (iii) wherein:
(i) is at least one monomer M;
(ii) is at least one imidoline nitroxide of the formula
and a source of free radicals Y•; and
(iii) is at least one alkoxyamine selected from the formula
wherein:
R, R
1
, R
2
, R
3
, X, M and Y are defined above;
Z is a group having at least one carbon atom such that the carbon centered radical
Z• is capable of initiating free-radical polymerization of monomer (M); Y and the reaction conditions are selected so that the Y(M)
n
—O moiety in the compounds of Formula (2) formed from reactants (i) and (ii) undergo facile homolysis; Z and the reaction conditions are selected so that the Z—O moiety and the Z(M)
n
—O moiety formed by reacting (i) with (iii) undergo facile homolysis; n is an integer of 1 or greater; and Y• can be produced thermally from the monomer (when one of the monomers is styrene or a styrene derivative) or from a free-radical initiator or combination of initiators.
Use of the nitroxides of Formula 1 (or the corresponding alkoxyamines) offers significant advantages over nitroxides previously employed in nitroxide-mediated polymerization: homopolymers, statistical copolymers and block copolymers which have controlled molecular weight, a narrow molecular weight distribution and a defined end-group fun
Anderson Albert G.
Gridnev Alexei
Moad Graeme
Rizzardo Ezio
Thang San Hoa
Costello James A.
Deshmukh Sudhir G.
E. I. Du Pont de Nemours and Company
Truong Duc
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