Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From carboxylic acid or derivative thereof
Reexamination Certificate
1999-04-05
2001-11-20
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From carboxylic acid or derivative thereof
C528S172000, C528S183000, C528S229000, C528S315000
Reexamination Certificate
active
06320018
ABSTRACT:
FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION
The invention relates to a supramolecular polymer containing monomeric units that form H-bridges with one another.
Such polymers are described in Lehn J.-M. Angew. Chem. 1988, 100.91, which describes polymers based on monomeric units that form 3 H-bridges with one another.
A drawback of the polymers described in the aforementioned publication is that even these 3-fold H-bridges do not associate sufficiently for many possible applications of supramolecular polymers. It has been found that no association constants higher than 10
5
M
−1
can be realized for 3-fold H-bridges with neutral molecules. These supramolecular polymers have thus shown no properties characteristic of polymers with only covalent bonds between the monomers. In addition, the synthesis of the building blocks that associate the most strongly is particularly difficult and cannot be carried out on a large scale.
SUMMARY OF THE INVENTION
The invention now provides polymers containing H-bridge-forming monomeric units in which the bond via the H-bridges is much stronger than with the known supramolecular polymers.
This is achieved according to the invention by using H-bridge-forming monomers which, in pairs, form at least 4 H-bridges with one another.
The term “supramolecular polymer” is understood to mean an organic compound that obtains its polymeric properties, for example with respect to mechanical strength, etc., essentially through a combination of covalent bonds and secondary specific interactions, the latter preferably having a high bond strength and contributing substantially to the polymeric behaviour.
There has for many years been an interest in supramolecular polymers in which the monomers are at least in part bound to one another via H-bridges.
Advantages of such polymers are that, in principle, materials with polymeric properties can be obtained in which the bond via the H-bridges can be used in a reversible manner, and that the polymer can be composed from simple low-molecular-weight units. As the H-bridges are much weaker at higher temperatures, implying a more rapid exchange between monomers than at low temperatures, an important advantage is obtained in processing: at higher temperatures only monomeric units (that can be easily handled) are essentially present which, when the temperature is lowered, form a rigid, dimensionally stable polymer. The “polymerisation step” takes place under mild conditions in comparison with the polymerisation of polymers that are only covalently bound, and is greatly simplified because no catalysts or other additives have to be added.
DETAILED DESCRIPTION OF THE INVENTION
In a supramolecular polymer, H-bridge-forming monomeric units are, with the exception of the polymeric ends, bound via at least 2 bonds (“on at least 2 sides”). An H-bridge-forming monomeric unit is in the context of this invention understood to be a unit that is on at least one side linked via at least 4 H-bridges to another H-bridge-forming monomeric unit in the supramolecular polymer, and is moreover on at least one side bound in the supramolecular polymer via a different, for example covalent, bond. In the case of a linear supramolecular polymer consisting exclusively of H-bridge-forming monomeric units the H-bridge-forming monomeric units are for example bound on 2 sides to the adjacent H-bridge-forming monomeric unit, with there being a covalent bond on one side and on the other side a bond via at least 4 H-bridges.
The H-bridge-forming monomeric units that can be used in the process according to the invention may be self-complementary, which means that at least 2 identical monomeric units form at least 4 H-bridges with one another; it is however also possible for the supramolecular polymer to contain 2 (or more) different types of H-bridge-forming monomeric units, with 2 different monomeric units always forming at least 4 H-bridges with one another. A combination is of course also possible. Preferably, the H-bridges are oriented parallel to one another. Particularly suitable H-bridge-forming monomeric units are those units that contain a structural element having the general form (1) or (2)
in which the C-Xi and C-Yi linkages each represent a single or double bond, n is 4 or more and X
1
. . . X
n
represent donors or acceptors that form H-bridges with the H-bridge-forming monomeric unit containing a corresponding structural element (2) linked to them, with X
i
representing a donor and Y
i
an acceptor and vice versa.
The H-bridge-forming monomeric units preferably have an essentially flat, rigid structure; in particular, the monomeric unit preferably contains one or more flat 6-rings and/or one or more H-bridges. In a linear supramolecular polymer the bonds preferably associate via the H-bridges only in the direction of the supramolecular polymer chain.
The invention is in particular aimed at H-bridge-forming monomeric units having 4 donors or acceptors, so that they can in pairs form 4 H-bridges with one another. Preferably the H-bridge-forming monomeric units have 2 successive donors, followed by 2 acceptors, for example monomeric units according to formula 1 with n=4, in which X
1
and X
2
both represent a donor and an acceptor, respectively, and X
3
and X
4
both an acceptor and a donor, respectively.
A particularly suitable H-bridge-forming monomeric unit that can be used in the polymers according to the invention is the compound (3.a) or the tautomeric form (3.b) thereof:
The H-bridge-forming monomeric units according to formulas 3.a and 3.b, respectively, may be bound in the supramolecular polymer in various ways. These H-bridge-forming monomeric units may for example be bound in the supramolecular polymer via a linking unit R
2
, with R
1
representing a random side chain, or vice versa, while it is also possible for the supramolecular polymer to contain linkages via both R
1
and R
2
.
As side chains, R
1
and R
2
may in principle represent any group that is inert in the formation of the supramolecular polymer, for example an alkyl, alkoxy or aryl group, whether or not substituted, or groups containing esters or ethers; the side chain may however also be a polymeric chain. The number of C atoms in these groups is in no way critical and lies for example between 1 and 40 C atoms, in particular between 1 and 20 C atoms. Preferably the side chain is an alkyl group.
As linking units, R
1
and R
2
may also represent all kinds of shorter or longer chains, for example saturated or unsaturated alkyl chains, siloxane chains, ester chains, ether chains and any chain of atoms used in traditional polymer chemistry, whether or not substituted.
These self-complementary compounds can be easily prepared on a large scale and can be easily modified.
The invention also relates to compounds containing structural elements having the general formula 4.a or 4.b.
where ″″ stands for an H-bridge.
Polymers according to the invention may be composed in several ways. The polymers may consist substantially of H-bridge-forming monomeric units with a low molecular weight, optionally mixtures of such H-bridge-forming monomeric units, as a result of which an essentially linear polymer may be formed; also conceivable on the other hand are (essentially linear) polymers in which the H-bridge-forming monomeric units are linked to 2 ends of the polymers so that polymeric chains are linked to one another via the H-bridges. In addition, a number of H-bridge-forming monomeric units can be grafted onto polymers, as a result of which a form of cross-linking via H-bridges may be obtained. Mixed forms are of course also possible. Both low- and high-molecular, linear or branched polymers can be used as the polymers, for example polymers known from traditional polymer chemistry, or mixtures of such polymers.
REFERENCES:
patent: 433188 A (1991-06-01), None
patent: 2657082 (1991-07-01), None
Derwent 91-179975125.*
Urbanski, et al. “Potential Antimalarial Compounds1. IX2. Pyrimidine Derivatives of Urea and Guanidine”, Journal of Medicinal Chemistr
Beijer Felix H.
Brunsveld Lucas
Meijer Egbert W.
Sijbesma Rintje P.
DSM N.V.
Hampton-Hightower P.
Pillsbury & Winthrop LLP
LandOfFree
Supramolecular polymer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Supramolecular polymer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Supramolecular polymer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2592224