Novel copolycarbonates containing 1,4:3,6-dianhydro-D-glucitol or 1,4:3,6dianhydro-D-mannitol units, with various methylene chain lengths, were synthesized by bulk and solution polycondensations, of several combinations of carbonate-modified sugar derivatives and aliphatic diols. Bulk polycondensations of 1,4:3,6-dianhydro-2,5bis-O-(phenoxycarbonyl)-D-glucitol or 1,4:3,6-dianhydro-2,5-bis-O-(phenoxycarbonyl)-Dmannitol with four ␣,-alkanediols having methylene chain lengths of 4, 6, 8, and 10, respectively, at 180°C afforded the corresponding copolycarbonates with numberaverage molecular weight (M n ) values up to 19. 2 ϫ 10 3 . 13 C NMR analysis disclosed that these polymers had scrambled structures in which the sugar carbonate and aliphatic carbonate moieties were nearly randomly distributed along a polymer chain. However, solution polycondensations between 1,4:3,6-dianhydro-2,5-bis-O-(p-nitrophenoxycarbonyl)-D-glucitol or 1,4:3,6-dianhydro-2,5-bis-O-(p-nitrophenoxycarbonyl)-D-mannitol, and the ␣,-alkanediols in sulfolane or dimethyl sulfoxide at 60°C gave well-defined copolycarbonates having regular structures consisting of alternating sugar carbonate and aliphatic carbonate moieties with M n values up to 33. 8 ϫ 10 3 . Differential scanning calorimetry demonstrated that all the copolycarbonates were amorphous with glasstransition temperatures ranging from 1 to 65°C, which decreased with increasing lengths of the methylene chain of the aliphatic diols. Additionally, all the copolycarbonates were stable up to 310 -330°C as estimated by thermogravimetric analysis.
Novel polycarbonates, with pendant functional groups, based on 1,4:3,6‐dianhydrohexitols and L‐tartaric acid derivatives were synthesized. Solution polycondensations of 1,4:3,6‐dianhydro‐bis‐O‐(p‐nitrophenoxycarbonyl)hexitols and 2,3‐di‐O‐methyl‐L‐threitol or 2,3‐O‐isopropylidene‐L‐threitol afforded polycarbonates having pendant methoxy or isopropylidene groups, respectively, with number average molecular weight (Mn) values up to 3.61 × 104. Subsequent acid‐catalyzed deprotection of isopropylidene groups gave well‐defined polycarbonates having pendant hydroxyl groups regularly distributed along the polymer chain. Differential scanning calorimetry (DSC) demonstrated that all the polycarbonates were amorphous with glass transition temperatures ranging from 57 to 98 °C. Degradability of the polycarbonates was assessed by hydrolysis test in phosphate buffer solution at 37 °C and by biochemical oxygen demand (BOD) measurements in an activated sludge at 25 °C. In both tests, the polycarbonates with pendant hydroxyl groups were degraded much faster than the polycarbonates with pendant methoxy and isopropylidene groups. It is noteworthy that degradation of the polycarbonates with pendant hydroxyl groups was remarkably fast. They were completely degraded within only 150 min in a phosphate buffer solution and their BOD‐biodegradability reached nearly 70% in an activated sludge after 28 days. The degradation behavior of the polycarbonates is discussed in terms of their chemical and physical properties. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3909–3919, 2005
A series of poly(ester amide)s were synthesized by solution polycondensations of various combinations of p-toluenesulfonic acid salts of O,OЈ-bis(␣-aminoacyl)-1,4:3,6-dianhydro-D-glucitol and bis( p-nitrophenyl) esters of aliphatic dicarboxylic acids with the methylene chain lengths of 4 -10. The p-toluenesulfonic acid salts were obtained by the reactions of 1,4:3,6-dianhydro-D-glucitol with alanine, glycine, and glycylglycine, respectively, in the presence of p-toluenesulfonic acid. The polycondensations were carried out in N-methylpyrrolidone at 40°C in the presence of triethylamine, giving poly(ester amide)s having number-average molecular weights up to 3.8 ϫ 10 4 . Their structures were confirmed by FTIR, 1 H-NMR, and 13 C-NMR spectroscopy. Most of these poly(ester amide)s are amorphous, except those containing sebacic acid and glycine or glycylglycine units, which are semicrystalline. All these poly(ester amide)s are soluble in a variety of polar solvents such as dimethyl sulfoxide, N,Ndimethylformamide, 2,2,2-trifluoroethanol, m-cresol, pyridine, and trifluoroacetic acid. Soil burial degradation tests, BOD measurements in an activated sludge, and enzymatic degradation tests using Porcine pancreas lipase and papain indicated that these poly(ester amide)s are biodegradable, and that their biodegradability markedly depends on the molecular structure. The poly(ester amide)s were, in general, degraded more slowly than the corresponding polyesters having the same aliphatic dicarboxylic acid units, both in composted soil and in an activated sludge. In the enzymatic degradation, some poly(ester amide)s containing dicarboxylic acid components with shorter methylene chain lengths were degraded more readily than the corresponding polyesters with Porcine pancreas lipase, whereas most of the poly(ester amide)s were degraded more rapidly than the corresponding polyesters with papain.
Poly(ester carbonate)s with different compositions were synthesized by bulk polycondensation of 1,4: 3,6-dianhydro-d-glucitol with diphenyl sebacate and diphenyl carbonate in the presence of zinc acetate as a catalyst. Most of the poly(ester carbonate)s as well as the corresponding polycarbonate were amorphous, except the poly(ester carbonate) with a small carbonate content and the corresponding polyester, which are semicrystalline. All these poly(ester carbonate)s are soluble in chloroform, pyridine, dimethylformamide, dimethyl sulfoxide, and N,N-dimethylacetamide. Soil burial degradation tests, biochemical oxygen demand (BOD) measurements in an activated sludge, and enzymatic degradation tests indicated that these poly-(ester carbonate)s are potentially biodegradable. The biodegradability was found to be maximum for the poly(ester carbonate)s with carbonate contents of 10 -20 mol % and to decrease markedly for the poly(ester carbonate)s with the carbonate content above 50 mol %. The biodegradability of the poly(ester carbonate)s is discussed in terms of the crystallinity, glass transition temperature, and surface hydrophobicity of the polymer films.
We investigated restricted diffusion of ionic species in glucitol-type lithium polymer electrolytes by observing echo-intensity changes of pulsed gradient spin echo NMR which reflect carrier diffusion behavior. Echo attenuation showed an anomalous feature attributable to deviation from random walk migration due to the restricted diffusion. The attenuation behavior depended on the diffusion time for measurement, Δ, in the range of 40 ms < Δ < 160 ms. This revealed that the size of the boundary structure which causes diffusion restriction was micrometer order. We speculated that a kind of micron size domain, which is an aggregation unit of entangled polymer chains, is responsible for the diffusion restriction. Simulations based on a rectangular model showed characteristic features of echo-changing behavior against two dominant factors: inherent diffusion coefficient, D, and domain size, a, which depend on variable parameters, observed temperature, T, and salt concentration, C, of the polymer electrolyte. Estimated D and a of the anion species by fitting the experimental data to a restricted diffusion model increased with increasing T and C. On the other hand, D and a of the cation species showed decreasing tendency with increased T and C. This difference would be attributed to their migration mechanisms: The cation is attracted by oxygen sites and takes the hopping process from site to site along the polymer chain in migration, whereas anion is weakly attracted by the polymer, leading to the migration free from the site-hopping process. Coulombic effect would provide stronger restricted situation on the cation compared with that due to the morphological domain structure, leading to the anomalous change in restriction parameters.
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