No-matrix resins

No-matrix resins, i.e., resins devoid of inert matrix as described by Bolto et al. constitute a novel way of enhancing the capacity of thermally regenerable resins. In the idealized structure of a no-matrix resin, active groups of one type are grouped into domains of size 0.01-5 pm, adjacent to domains of opposite character in porous particles of the conventional size 300-1200 pm. Thermally regenerable capacities up to 2.1 meq/g should be possible in the absence of any diluent. 

In no-matrix resins, triallylamine is used as the self-crosslinking monomer with methacrylic or acrylic acid as the acidic monomer. The crosslinked resin obtained by polymerizing a mixture of triallylamine and an acidic monomer would be expected to have the sites arranged so that maximum interaction occurs between amine and carboxylic acid groups as shown in Fig. 9 Indeed, such particles have no thermally regenerable capacity and electron micrographs of these products show a uniform gel phase with no segragation of sites into domains. Obviously, measures are necessary to prevent such interactions. Several approaches have been made to minimize the internal salt formation in no-matrix resins these are discussed below. 

No matrix resins have also been prepared by the polymerization of methacrylamide (MAAm) or acrylamide (AAm) and TAA using y-irradiation. The solvent used for polymerization has a profound influence on the capacity, but a smaller effect on the swelling behaviour. Ethanol, methanol, and DMF are to be preferred to just water, and ethanol is found to be the best solvent for this system giving a resin having a capacity of 1.07 meq/g when the ratio of MAAm to TAA in the polymerization mixture is 1.7. 

Fig. 11. Pictorial representation of no-matrix resin prepared by using electrically neutral acid precursor...

The electron micrographs of no-matrix resins prepared by the precursor method show that there are discrete acidic and basic domains in which the acidic groups are in effect, embedded in a matrix of the polyamine. A possible mode of polymerization is one in which block copolymers are formed as a result of the formation, initially, of a macroradical. The marked dependence of the thermally regenerable capacity of a resin on the solvent suggests that a macroradical may be involved, since their formation and stability are also greatly dependent on the solvent. However, a study of some linear analogues suggests that this is an oversimplified picture. 

While the thermally regenerable plum pudding resins can be classified as composite resins without ambiguity, the authors are of the opinion that it may not be appropriate to use such a classification for thermally regenerable no-matrix resins. Unlike the plum pudding resin, which is obtained by blending two independent resins in an inert matrix, the no-matrix resin is devoid of aify inert matrix and refers to a polymer matrix in which the weakly acidic and weakly basic domains are segregated. 

Modified nylons are blends of nylon resins and specially grafted nylon resins. In the Du Pont family of Zytel resin, certain blends have been designated Supertough to emphasize the improvement in impact that blends provide over standard resins. General Electric s Noryl GTX resins consist of a nylon matrix resin and a PPO resin in dispersed form. A highly sophisticated blend, it maintains a filled nylon s HPT with no sacrifice of impact resistance. 

ODUR-110-WR, but no detailed lithographic evaluation has been published. Since the matrix resin is cyclized rubber, one would expect the same swelling limitation on resolution evident in conventional negative photoresists. 

For non-conducting fibers, such as glass, the matrix resin is the more conductive phase, at least early in cure, and one would expect some internal polarization effects to be visible in parallel-plate data. However, in spite of a large body of literature on glass fiber composites (see Sect. 5), we have found no clearly documented cases of Maxwell-Wagner effects in fiber-reinforced composites. We speculate that... 

Some gem quality pieces of ammolite are stabilised with epoxy or other resin before cutting, to prevent the delicate surface from flaking. However, some material is cut without prior treatment. The cut pieces are then polished, and finished in one of three ways. The most valuable and rare pieces are solid shell, with no matrix on the back. Thinner slices are made into doublets to reinforce the material by adding an extra layer of natural matrix on the back. Triplet stones have both an extra matrix back, and a cap of synthetic spinel or quartz. 

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