Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From sulfur-containing reactant
Reexamination Certificate
2001-02-12
2003-07-08
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From sulfur-containing reactant
C528S226000, C528S228000, C528S230000, C528S242000, C528S295000, C528S482000, C528S486000, C528S487000, C528S492000
Reexamination Certificate
active
06590067
ABSTRACT:
FIELD OF THE INVENTION
The present invention is in the field of polymers containing basic groups and ion-exchange groups. The invention relates in particular to methods for lateral chain modification of aryl main chain polymers with aromatic ketones and aldehydes containing basic nitrogen (N) groups and to the polymers made according to the methods.
RELATED ART
A) Polymers Modified with Basic N
There are still relatively few basic N-modified polymers on the market, the most important of which are mentioned below:
poly(4-vinyl pyridine), poly-2-vinyl pyridine) and copolymers.
These two polymers are commercially available, also as block copolymers with polystyrene. They are used for example as pre-stages for anion exchange membranes (Reiner, Ledjeff
1
, Gudernatsch, Krumbholz
2
) or complexed with Schiff's bases containing cobalt for selective oxygen permeation
3
. The drawback with this class of polymer is the tertiary C—H-bond in the polymer main chain, which is susceptible to oxidation.
Polybenzimidazols
Polybenzimidazols are a class of polymers which have considerable chemical and mechanical stability. Many types of polybenzimidazols (fully and partly aromatic) have already been synthesised and examined
4
. However, only a few types are produced commercially, of which the most important is the polymer PBI (poly[(2,2-m-phenylene)-5,5′-bibenzimidazol) produced by Celanese under the commercial name CELAZOLE. This polymer is used, inter alia, in the form of low-flammability textiles
5
for the Fire Brigade. The drawbacks with this polymer are that it is difficult to dissolve in organic solvents and so has poor working properties. In addition, this polymer is very expensive.
Polyethylene imine
Polyethylene imine is used in organic chemistry and biochemistry as a precipitating agent for proteins
6.
The advantage of this polymer is that by virtue of its highly hydrophilic nature (1 N on 2 C), it is water soluble and therefore, in its pure form, will not form any resistant membranes. Furthermore, by virtue of its purely aliphatic structure, it is not very chemically stable.
B) Anion Exchange Polymers and Membranes
The commercial anion exchange polymers and membranes can be divided into two main categories:
anion exchange polymers which are produced by reaction of chlorinated
7
or bromomethylated
8
polymers with tertiary amines. The drawback with this reaction is the carcinogenic nature of the halomethylation reaction and the lack of chemical stability of the aromatic-CH
2
—NR
3
+grouping.
anion exchange polymers produced by the alkylation of tertiary N, for example of poly(vinyl pyridine)
1,2,9
with halogen alkanes
1,2
. The disadvantage with this reaction is that only very few commercial polymers with tertiary N are available (see above) and thus the range of membrane properties to be achieved is limited. The drawback with poly(vinyl pyridine)s is limited chemical stability (see above).
C) Cation Exchange Polymers Sulphonated in the Lateral Group
There are very few commercial polymers and membranes of this type. The most important are:
nafion
10
This polymer has a perfluoralkyl main chain and a perfluorether lateral chain at the end of which hangs a sulphonic acid group. This polymer is used in applications which require great chemical membrane stability, for example, in membrane fuel cells
11
. The disadvantage of this polymer is its high price ($800/sq.m) and complicated production process
10
.
poly-X 2000
12
This polymer consists of a poly(phenylene) main chain and an aryl lateral chain. The precise name of this polymer is poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene). This polymer is sulphonated
12
only at the end of the lateral chain. Reportedly
12
, this polymer in the sulphonated form has good proton conductivity levels even at temperatures in excess of 100° C. at which the proton conductivity of sulphonated poly(ether ether ketone) (PEEK) drops markedly. This property could be brought out by a better association of the sulphonic acid groups in the poly-X 2000, since the sulphonic acid groups are in the lateral chain in the case of the poly-X 2000—in the sulphonated PEEK, the sulphonic acid groups are in the main chain and consequently, on account of the rigidity of the PEEK main chain, they associate less readily. A drawback with this polymer is its poorer thermal stability compared with sulphonated PEEK
12
and the fact that it is not commercially available.
SUMMARY OF THE INVENTION
The invention is directed to:
(1) A method for the lateral chain modification of engineering aryl main chain polymers with arylene-containing basic N-groups by the addition of aromatic ketones and aldehydes containing tertiary basic N-groups (such as for example tertiary amine, pyridine, pyramidine, and triazine) to the metallized polymer.
(2) Lateral chain modified polymers obtainable by the methods of the invention, whereby the lateral chain contains at least one aromatic group which carries a tertiary basic N.
(3) A method for quaternizing the tertiary N of the modified polymers obtainable according to the invention with halogen alkanes in order thus to incorporate anion exchanger groups into the lateral chain modified polymer.
(4) Engineering aryl main chain polymers carrying in the lateral chain anion exchanger functions and obtainable by the methods of the invention.
(5) A method for the lateral chain modification of engineering main chain polymers with arylene-containing basic N groups by the following reaction of aromatic carboxylic acid Ar—COOR′ containing tertiary basic N groups (such as for example tertiary amine, pyridine, pyramidine, and triazine) with the metallized polymer P—Me:
(6) Lateral chain modified polymers obtained by the methods of the invention in which the side chain contains at least one aromatic group which carries a tertiary basic N.
(7) A method of quaternizing the tertiary N of the modified polymers obtained by the methods of the invention with halogen alkanes to incorporate anion exchanger groups into the lateral chain modified polymer.
(8) Engineering aryl main chain polymers carrying in the lateral chain anion exchanger functions obtainable by the methods of the invention.
(9) A method for the lateral chain modification of engineering aryl main chain polymers with aromatic groups containing sulphonic acid radicals by the following sequence of reactions:
(9a) Reaction of the aromatic carboxylic acid ester Ar—COOR′ or carboxylic acid halide Ar—COHal with the metallized polymer P—Me:
(9b) Controlled electrophilic sulphonation of the lateral group with sulphuric acid SO
3
/P(O)(OR)
3
, CISO
3
H, or other sulfonating reagent. The lateral group is in this case so selected that its reactivity for sulphonation is substantially higher than the reactivity of the polymer main chain for sulphonation.
(10) Engineering aryl main chain polymers which only carry sulphonic acid functions in the lateral chain, obtainable by the methods of the invention.
(11) Membranes of the polymers obtainable according to the present invention, in which the membranes may be unvulcanised or covalently cross-linked.
(12) A method of producing acid-based blends/acid-based blend membranes from the basic polymers of the invention with polymers containing sulphonic acid, phosphonic acid or carboxyl groups.
(13) A method of producing acid-based blends/acid-based blend membranes from the basic polymers of the invention with the polymer of the invention containing sulphonic acid groups.
(14) Acid-based blends/acid-based blend membranes obtainable by the methods of the invention, whereby the blends/blend membranes may in addition be covalently cross-linked.
(15) Use of the ion exchange polymers of the invention in the form of membranes in membrane processes such as in polymer electrolyte membrane fuel cells (PEFC), direct methanol fuel cells (DMFC) and electrodialysis.
(16) Use of hydrophilic polymers of the invention containing the basic N in the lateral group in the form of membranes in dialysis and in reversed osmosis, nanofiltration, diffusion dialysis, ga
Haring Thomas
Kerres Jochen
Ullrich Andreas
Truong Duc
Universitaet Stuttgart
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