A block copolymer of cellulose and polystyrene (PS) was synthesized through atom transfer radical polymerization. Macroinitiators (MIs) were prepared by introducing 2-chloroacetamide to the reducing end of cellulose (degree of polymerization¼20, 50, 250). Subsequently, MIs were copolymerized with styrene monomer in a system of N,N,N ¢,N 00 ,N 00 -pentamethyldiethylenetriamine/CuCl or CuBr/ascorbic acid at 130 1C. The resulting copolymers were characterized by 1 H nuclear magnetic resonance and size-exclusion chromatography. The kinetic study indicated that the polymerization was controllable. The efficacy of copolymers in compatibilizing an immiscible cellulose/PS blend was confirmed by microscopic observation. The mechanism of thermal and thermo-oxidative decomposition of the blend was investigated by thermogravimetry.

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The carbon isotope ratios of bog peat in the Ozegahara peatland, Japan, were measured. The vertical variation of the bulk peat featured: 1) rapid decrease of the carbon isotope ratio (δ 13 C) near the surface, 2) broad rises in the ratio around depths corresponding to 3000, 5500, 7500 years BP with a period of approximately 2500 years, and 3) a further decrease toward the bottom. In order to understand the reasons for the changes, peat components were separated and their isotopic composition measured along with modern peat-forming vegetation. The selective decay of holocellulose is responsible for the rapid decrease of δ 13 C in the surface layers, and the transition from earlier vegetation caused the further decrease of δ 13 C near the bottom. The decay constant for holocellulose was estimated to be as small as 0.001 yr -1 . The variation of δ 13 C seemed to be synchronized with sea level change, but showed poor correlation with solar activity and the temperature change estimated from pollen analysis. The δ 13 C of peat mosses lacking in stomata would increase with the rise in atmospheric CO 2 . The increase in the atmospheric CO 2 occurring synchronously with sea level rise could be the reason for the periodical change. Some climatic information of the Holocene period may have been recorded in the Ozegahara bog peat.

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