The blend films of poly(butylene succinate) (PBS) and cellulose triacetate were prepared by using the solvent-cast technique. Titanium tetraisopropoxide (TP) was further added to the blend during the blend process. The effects of the addition of TP on the structure and hydrolysis behavior of the blend films have been investigated with GPC, FT-IR, 13C-NMR and so on. As a result, we have the following conclusions: (i) the addition of TP accelerates the hydrolysis of blend films, (ii) the addition of TP does not influence the water vapor permeation of the blend films, and (iii) TP reacts with the esteric site of PBS and scissors the main chain of PBS
The influence of chain entanglement density on the ultra-drawing of ultra-high-molecular-weight polypropylene (UHMW-PP) has been studied by comparison of the gel-like spherulite pressing method (the GSP method) and the gel-casting method, using two kinds of specimens prepared from 2.0wt% solution of UHMW-PP. The only major difference between the specimens in both methods is the cooling rate of solution. The influence of chain entanglement density in an undrawn specimen on the increase in strength and modulus with ultra-drawing has been discussed. It was found that the slopes of strength and modulus versus draw ratio (DR) were steeper in the gel-casting method. This difference was concluded to be due to the difference of chain entanglement density of undrawn specimens, by considering the fine structure and the maximum draw ratio (λmax). And, it was considered that the differences in the above slopes between both methods could not be explained by the changes of crystalline orientation and crystalline size but by the change of fraction of folded-chain crystals (or extended-chain crystals) with ultra-drawing.
Through the measurements of dimensional change and birefringence, density and small-and wide-angle X-ray diffraction of drawn poly(ethylene terephthalate) (PET) fibers after the heat treatment under various conditions, relations between the fine structure and characteristics of spontaneous elongation was investigated. It was concluded that in the PET fibers which show spontaneous elongation: 1) Crystallites are oriented to a certain direction with respect to the fiber axis, while molecular chains in the amorphous region are in the unoriented state. 2) Crystalline region is composed of folded chain crystals. 3) Crystalline regions are contacted with each other at a particular angle. It was also considered that irreversible spontaneous elongation of PET fiber is associated with the growth of crystallites, and therefore the elongation ratio increases with an increase in the heat-treatment temperature.
The applicability of chitosan to the adsorption treatment of anionic dyes in waste water from dyeing was evaluated. Factors affecting adsorption were investigated. It was revealed that the size of dyes resulting from molecular weight or aggregation affected the adsorption of dyes on chitosan. In addition the effects of temperature and the addition of sodium chloride for decolorization of waste water are discussed
Cellulase was covalently modified with a water soluble polymer; maleic acid methylvinylether copolymer. The molecular weight of the cellulase modified with the polymer was increased. Actually the crude modified enzyme includes the modified cellulase fraction and the unmodified cellulase fraction. And the specific activity of the crude modified cellulase was nearly equal to that of the native cellulase. Optimum pH of the modified cellulase shifted slightly to alkaline region and thermal stability was increased. When the crude modified cellulase was used in the cotton yarns treatment, the rate of weight loss for the yarns was as fast as that of native cellulase. However, the breaking strength of the yarns treated with the modified cellulase was higher than that of the yarns treated with the native cellulase. The rate of weight loss with the modified cellulase fraction was very slower than that with the native cellulase. These results might suggest that the modified cellulase could not easily penetrated into the amorphous region because of its high molecular weight.
Rosin-alum internal-sized handsheets were analyzed by electron spectroscopy for chemical analysis (ESCA) and time of flight secondary ion mass spectrometry (TOF-SIMS) to reveal the distribution of rosin sizes and aluminum components in the handsheets. Results obtained from ESCA showed that distribution of rosin-sizing agents in handsheets became more even as pulps were beaten to higher degree. TOF-SIMS images of cross sections of the handsheets showed that rosin-sizing agents and aluminum components existed both on pulp-fiber surfaces and inside the pulp-fiber wall. Furthermore, these images showed that rosin sizes were distributed more evenly in handsheets and inside pulp-fiber walls with increasing beating degrees. These observations were confirmed by ESCA results. The distribution of rosin-sizing agents in handsheets and inside pulp-fiber walls was found to become more homogeneous by increased beating degrees.