Menthyl methacrylate

More recently, such studies have been extended to nonhydrocarbon chiral comonomers, for example, menthyl acrylate and menthyl methacrylate (379, 382). Of notable interest, especially for microsequence investigation, are fluorescence studies combined with CD spectra carried out on copolymers containing the caibazole fragment (382). It is interesting to note that the induction of... 

In the case of poly-menthyl-methacrylate, an evaluation of the type and degree of stereoregularity of the unfractionated polymers, obtained by different polymerization processes, has been made by converting poly-menthyl-methacrylate into polymethyl-methacrylate and then determining the stereoregularity of the methyl derivative thus obtained by N. M. R. analysis (135). 

The fact that large-modulation SRGs are formed only above a certain threshold amount of functionalization was also shown by Andruzzi et al.J for amorphous as well as LC polymers. They investigated copolymers derived from two photochromic monomers, 6-(4-oxy-4 -cyanoazobenzene)h x-l-yl methacrylate and 8-(4-oxy-4 -cyanoazobenzene)oct-l-yl methacrylate, and a nonphotochromic comonomer, (-)-menthyl methacrylate. Considerable amplitudes were obtained for all polymers with more than 30% of azofunctionalization. The maximum amplitudes were observed for copolymers possessing 75-80% of dye content, not the fully functionalized homopolymers. 

Second virial coefficient of poly(p-menthyl methacrylate)... 

Poly(5-p-menthyl methacrylate) exhibits an intermediate value. It has the most flexible, yet most bulky substituent since no bridging is present. Poly(isobomyl methacrylate) has the lowest Coo value its substituent, which is bridged, is more rigid but smaller than the menthyl group. Poly(l-adamantyl methacrylate) with a doubly bridged ring has the largest C. Probably, the observed C o variations could not be predicted. 

Referred to one monomeric unit, at 25(poly-menthyl-methacrylate) and 15 °C [poly-(/ )-l-phenylethyl-methacrylate]. 

Matsuzaki and Sugimoto [12] have shown that the specific rotation in the copolymer of 1 -menthyl methacrylate with maleic anhydride or TV-p-tolylmaleimide depends on the 1-menthyl methacrylate content, and that the copolymers obtained become optically inactive after cleavage of the optically active side chain by hydrolysis with sulfuric acid. 

Fig. 10a and b. Fluorescence spectra of 9-iso-propylcarbazole (NIPC) and of copolymers of N-vinyl-carbazole (NVC) with (—)-menthyl acrylate (a) and (—)-menthyl methacrylate (b) having different NVC contents... 

For all copolymers of NVC with optically active menthyl derivatives the variation in induced circular dichroic absorption exhibits a maximum with increasing NVC content. For copolymers of NVC and (—)-menthyl vinyl ether this maximum is very pronounced and occurs at approximately 20% NVC content . Copolymers of NVC with (—)-menthyl acrylate and (—)-menthyl methacrylate show rather similar maxima, at about 40% and 50% NVC contents respectively. Typical trends are shown in Fig. 16. 

Fig. 16. Variation of the differential dichroic absorption (Ae) with chemical composition in copolymers of N-vinylcarbazole (NVC) with — — (—)-menthyl methacrylate (240 nm) —A— (—)-menthyl acrylate (257 nm) — — (—)-menthyl vinyl ether (265 nm)...

Poly(5-p-menthyl methacrylate) (Poly(]-(5-p-menthyloxycarbonyl)-]-methylethylene))... 

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