Poly , matrix resin

On processing butadiene-styrene thermoplastic rubbers, the major effect on mechanical property deterioration is a result of the agglomeration of styrene particles [58]. For ABS (acrylonitrile-butadiene-styrene) resins, mechanical properties deteriorate on processing due to double bond oxidation. At more severe conditions, a decrease of the matrix resin [poly(styrene-co-acrylonitrile)] molecular weight is a superimposed effect [59]. 

Figure 13. Bisarylazide-rubber resists. The matrix resin is cyclized poly(cis-isoprene). The sensitizers are bisarylazides. A typical structure of one commonly employed sensitizer is provided.

Table 22. Properties of graphite fibre composite using poly as a matrix resin...

Addition poly(imide) oligomers are used as matrix resins for high performance composites based on glass-, carbon- and aramide fibers. The world wide market for advanced composites and adhesives was about 70 million in 1990. This amounted to approximately 30-40 million in resin sales. Currently, epoxy resins constitute over 90% of the matrix resin materials in advanced composites. The remaining 10% are unsaturated polyester and vinylester for the low temperature applications and cyanate esters and addition poly(imides) for high temperatures. More recently thermoplastics have become important and materials such as polyimides and poly(arylene ether) are becoming more competitive with addition polyimides. 

Throughout this chapter the chemical concepts employed to synthesize and cure addition poly(imides) have been discussed and their use as matrix resins for fiber composites has frequently been mentioned. The most important property of the imide backbone structure is the inherent thermal stability. The target of achieving the temperature performance of linear poly(imide) has not been reached, because of the aliphatic nature of the reactive endgroups, and because of the low molecular weight of the imide backbone required for processing. Future developments of addition polyimides will, as in the past, focus on the requirement of high thermal and thermal oxidative stability of the crosslinked... 

Research has also been aimed at the development of more-transparent base-soluble matrix resins. For example, novolacs prepared from pure p-cresol absorb less strongly at 250 nm than do typical photoresist novolacs containing a mixture of cresol isomers. Unfortunately, p-cresol novolac is only sparingly soluble in aqueous base and has limited usefulness (28, 57). Other examples of more-transparent matrix resins include poly(dimethyl glutarimide) (PMGI) (58) and copolymers of methyl methacrylate (MMA) and methacrylic acid (MAA) [P(MMA-MAA)]. 

Polymer chemistry is important in obtaining adhesion to the glass surface (Figure 10). The tensile reinforcement factor—the ratio of tensile strengths of the reinforced system to the matrix resin—is used as a measure of adhesion. Two dissimilar polymers, polypropylene and nylon, are used to illustrate the importance of polymer chemistry. Polypropylene is an inherently difficult polymer to reinforce because of its nonpolar nature and lack of reactivity. Nylon, on the other hand, is highly polar and is one of the easiest thermoplastics to reinforce. The modified poly-... 

There are no accurate determinations of the overall contributions of peptide components to the compositions of HS and of SOM. The difficulties arise from the problems of separating these from other components of the SOM mixtures. Use of DMSO + 1% 12M HC1 and XAD-8 resin [(poly)methylmethacrylate] technology enabled Appelqvist et al. (1996) to decrease the amino acid content of a HA by 23%, and the decrease was uniform for the different amino acid groupings. This still left considerable amounts of peptide material in association with the HAs. Some may well have been in association with the humic matrix, and some may have been covalently linked to the humic core through, for example, the formation of Schiff... 

Wijdenes and Geomini (170) examined the effects of the phenolic resin composition, its molecular weight distribution, solvent composition, and prebake temperature on the interfacial layer formation. They found that combined use of poly(p-vinylphenol) (structure 3.10) as matrix resin and cyclohexanone as the casting solvent in the diazoquinone resist formulation minimizes mixing of the two layers and yields a capped PCM structure without any plasma treatment. 

Hedrick, J.L. Yilgdr, I. Wilkes, G.L. McGrath, J.E. Chemical modification of matrix resin networks with engineering thermoplastics. I. Phenolic hydroxyl terminated poly(aryl ether sulfone)-epoxy systems. Polym. Bull. 1985, 13, 201-208. 

O-methylated PHOST [179]. This terpolymer was originally developed as a chemically amplified laser resist for circuit board application [180] and then as a single layer 193 nm positive resist [181], which will be described in more detail later. Another interesting three-component approach is the use of a N-acetal polymer as a dissolution inhibitor of poly(3-methyl-4-hydroxystyrene) [182]. A deep UV resist consisting of poly(3-methyl-4-hydroxystyrene-co-4-hydroxystyrene), poly(N,0-acetal), bis(arylsulfonyl)diazomethane, and a photobase was reported from Hoechst (currently Clariant). The function of the photobase is described later. A copolymer of 4-hydroxystyrene with styrene was also employed as a matrix resin. 

Hed Hedrick, J. L., Yilgor, I., Jurek, M., Hedrick. J. C., Wilkes, G. L., McGrath, J. E. Chemical modification of matrix resin networks with engineering thermoplastics 1. Synthesis, morphology, physical behaviour and toughening mechanisms of poly (arylene ether sulfone) modified epoxy networks. Polymer 32 (1991) 2020-2032. 

The Choice of a Matrix Resin. As was mentioned earlier, the common matrix resins for today s lithography are phenolic resins such as Novolac and poly(4-hydroxystyrene). Though some of our early work had involved simple water soluble alcohols such as poly(vinyl alcohol), schemes for their reversible in situ insolubilization were sometimes complicated by irreversible processes or side-reactions. As a result we chose to test the water-soluble linear polymer that is obtained by free-radical polymerization of 2-isopropenyl-2-oxazoline, 1. Monomer 1 can be polymerized through a variety of techniques, as shown in Scheme 1 (6,7). Both radical or anionic polymerization conditions lead to a polymer containing pendant oxazoline rings, while a more complex structure is obtained under cationic conditions as both the vinyl and the oxazoline moieties are reactive. 

In practice, the intrinsic reactivity of the oxazoline ring with cationic species may render the poly(2-isopropenyl-2-oxazoIine) resin 2 too reactive for use in a fully water-soluble resist. However the ability of oxazoline ring to react with a variety of simple molecules makes polymer 2 well-suited for this study focused on the exploration of new designs and the demonstration of key concepts. We are currently evaluating several other types of reactive matrix resins that may ultimately be better suited than 2 for the design of fully functional positive tone water-soluble resists. 

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