A simple method for preparing monoclinic single crystals of ZSM-5 is developed. The ZSM-5 crystals are pressed with a weight of 50 g at an angle of 45° relative to the b and c crystallographic axes of twin ZSM-5 crystals while the temperature is simultaneously increased to 573 K. The temperature is then slowly reduced to 313 K, and these steps are repeated three times. The monoclinic structure of the single crystals of ZSM-5 produced using this method is then determined.

l f a y 20, 195s COMMUNICATIONS TO THE EDITOR 2595 bically on a minimal salt medium containing Dgalacturonic acid as the sole carbon source. After 24 hours a t 37", the cells were harvested, disrupted by sonic vibration and the extract partially purified by isoelectric precipitation. A reaction mixture containing 50 pmoles of either I or I11 was incubated separately with the extract for one hour a t 37" and the reaction products isolated by chromatography on Dowex-1-formate5 or by paper chromatography with ethyl acetate: acetic acid:water (3 :1:3) as the solvent system. In either case, there was a clear separation of unreacted starting material and of a more rapidly moving component which was isolated and identified as I1 or IV, respectively.Both of the unknown products gave color reactions characteristic of uronic acids6,' but which were stable to bromine water under conditions where the alduronic acids were completely oxidized. Upon treatment with HI04 under acidic conditions,8 formaldehyde was not formed and the presence of a 2-keto acid therefore presumed unlikely. Quantitative measurement at pH 6.29 showed that 3.1 and 2.8 moles of HI04 were taken up per mole of I1 and IT?, respectively. The glycolic acid formedl0 was 1.0 and 1.1 moles per mole of I1 and IV, a result in close accord with the theoretical values for 5-keto acids.Further evidence that the enzymatic reaction products were I1 and I V was provided by reduction with KBH4. The resulting aldonic acids were lactonized and chromatographed on paper in three different solvent systems. Upon visualization of the lactones with hydroxylamine and FeCla,ll it was seen that I1 yielded galactono-and altronolactones while IV yielded gulono-and mannonolactones. These results are definitive for the structures as written.The crystalline brucine salt of D-frUCtUrOniC acid was prepared by a modification of the procedure used to synthesize crystalline D-tagaturonic acid.I2 Paper chromatography in several solvents revealed that I1 invariably co-chromatographed with authentic D-tagaturonic acid and that IT' acted similarly with pure D-fructuronic acid. Upon incubation of the synthetic keturonic acids with the enzyme, the formation of the corresponding alduronic acids (I or IIIj was readily demonstrable. Finally, the crystalline brucine derivatives of I1 and IV were prepared and checked by mixed melting points with the authentic derivatives.Recent results' suggest that irradiation of polyethylene a t room temperature and doses below 29 X lozo e.v.g.-' causes no change2 in crystallinity, but that on fusion and solidification subsequent to the irradiation, the crystallinity decreased. \Ve have confirmed these results by a direct measurement a t room temperature of the amorphous content of polyethylene utilizing the infrared absorption bands3 a t lOS0 and 1303 cm. -I. The open circles of Fig. 1 demonstrate the constancy of the crystallinity of S5% crystallinc Mar-( I -i k l D ) / D x 1 0 2 ' 2 .o I .o 0 3.0 2 .o I .o 2 .o I .o 0 4 8 D x 1 6~' Fig. 1.-Open circles, are relati...

Polylactic acid (PLA) is a biomass material made of starch. Compact disc recordable (CD-R) discs with a PLA substrate were prepared and their properties were measured. Although the glass transition point of PLA is lower than that of polycarbonate (PC), the PLA substrate is usable for CD-R discs. It was confirmed that the substrate is usable for recordable optical discs at temperatures under 50 °C.