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The saccharogenic liquid obtained by the enzymatic saccharification of food wastes was used as a medium for production of bacterial cellulose (BC). The enzymatic saccharification of food wastes (SFW) was carried out by the cultivation supernatant of Trichoderma inhamatum KSJ1. 5.6 g/L of BC was produced in a new modified 50 L bubble column bioreactor by Acetobacter xylinum KJ1. The productivity was similar to that of a modified 10 L bubble column bioreactor (5.8 g/L). When pure oxygen was supplied into the scaled-up culture conditions, 6.8 g/L (12% enhancement) of BC was produced, indicating a very useful method for BC mass production. The oxygen uptake rate (OUR) and q O2 (specific oxygen uptake rate) were 0.214 mg-DO/L·min and 0.257 mg-DO/g-cell·min, respectively. The physical properties, such as morphology, molecular weight, crystallinity, and tensile strength of BCs produced in static culture (A), 10 L (B) and 50 L (C) modified bubble column cultures were investigated. All BCs showed fibrils with highly networking structure. The number average molecular weight of BCs in A, B and C was 2,314,000, 1,878,000, and 1,765,000, respectively. All of the BCs had a form of cellulose I representing pure cellulose. The relative degree of crystallinity showed the range of 79.6-86.0%. Tensile strengths of BC sheet in A, B and C were 1.75, 1.21, and 1.19 kg/mm 2 , respectively. In conclusion, BC production by the modified bubble column culture mode of 50 L brought more favorable results in terms of the physical properties and its ease of scale-up.

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ABSTRACT:The premelting behavior of bacterially synthesized polyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), abbreviated as P(HB-co-HHx), was investigated by two-dimensional Fourier-transform infrared (2D FTIR) correlation spectroscopy. The temperature-dependent dynamic spectra were measured over a temperature range of 25-300°C. We focused our study on the thermally induced intensity fluctuations of bands for CAO (1700 -1760 cm Ϫ1 ), COH (2910 -3010 cm Ϫ1 ) and COOOC groups (1220 -1310 cm Ϫ1 ) stretching vibrations. Changes of crystalline conformation due to the thermal perturbation could be detected by the intensity and location variations of those characteristic bands responding to the variations of dipole moments. 2D correlation analysis indicated that the appearance of fully amorphous component did not happen simultaneously with the disappearance of crystalline component, suggesting that there was an intermediate state between ordered crystalline and amorphous states in P(HB-co-HHx).

ABSTRACT:Ternary blends of Poly(ethylene terephthalate) (PET), Polyamide-6 (PA6) and phenoxy were prepared to compatibilize immiscible blends of PET and PA6. Phenoxy phase during melt mixing was characterized using electron microscopes, SEM and TEM. For PA6 matrix blends, it resided at the interface between PET and PA6 and forms an encapsulating layer during melt mixing. For PET matrix blends agglomerate particles were observed as a result of coalescence even though phenoxy encapsulated minor PA6 phase. The encapsulation of phenoxy onto PET or PA6 was interpreted in terms of a spreading concept combined with solubility parameter. Although phenoxy added as a compatibilizer does not stabilize the morphology it increases the tensile properties of PA6/PET blends.KEY WORDS Polymer Blend / Encapsulation / Compatibilization / Poly(ethylene terephthalate) (PET) / Polyamide-6 (PA6) / Phenoxy / Encapsulation by homopolymers may be an alternative for compatibilization of immiscible polymer blends when the preparation of compatibilizers such as block or reactive copolymers is not available. If a third polymer added moves to the interface between matrix and dispersed phase, and forms an encapsulating layer during melt mixing, it has potential to act as a compatibilizer. [1][2][3][4] This polymer should satisfy other prerequisites such as strengthening of the interface to become effective compatibilizer. Since simple encapsulation by third homopolymers generates two different weak interfaces between encapsulating polymer and matrix (or dispersed phase), the third must be carefully chosen to accomplish successful compatibilization. 5 This requirement may be one of the main reasons why encapsulation does not attract attention for compatibilization of immiscible polymer blends.Whether the third polymer forms an encapsulating layer or not depends on two different factors. First, a thermodynamic factor such as interfacial tension has been considered the main driving force for encapsulation of ternary polymer blends. A third polymer added to immiscible polymer blends tends to move to the interface and encapsulate the minor phase when the sum of interfacial tension associated with the third is smaller than the interfacial tension between the original pair. A spreading coefficient, λ ij , explains the importance of interfacial tension in the morphology of ternary polymer blends. 1 When polymer 3 is added to the immiscible blends of matrix polymer 1 and dispersed polymer 2, † To whom correspondence should be addressed. Kinetic factors such as melt viscosity affect final morphology irrespective of thermodynamic consideration. Nemirovski and coworkers 6 reported that when the viscosity of an encapsulating polymer, predicted from the interfacial tension difference, is higher than that of the minor phase, encapsulation is limited by high viscosity, thus balancing the thermodynamic driving force. Chemical reactions between blend components during mixing affect the morphology evolution of ternary polymer blends, as reported for ternary elas...

Abstract:In this study, we investigated the effects of oxidative permanent hair coloring agents on the dyeability and the damage of human hair. p-phenylenediamine and toluene-2.5-diamine sulfate were used as a hair coloring agent precursers. The degree of dyeability was checked by the change of CIELAB L* value according to dyeing time. And the damage of hair was evaluated by the tensile strength and morphological change of hair in SEM. When the hair was dyed, the CIELAB L* value was decreased with dyeing time regardless of the type of precursers. But when the hair was dyed after nutritional treatment, the CIELAB L* value showed lower level. This means that the nutritional treatment covers the scale of hair and protects the hair from the chemicals.

Generally, hair treatments by complementary actions to give a sense of activity are permanent setting, dyeing, and bleaching, etc. In this study, we investigated the wave formation ability and hair damage occuring in permanent setting and bleaching process. The wave formation ability was evaluated by the differences of length and curl diameter after permanent setting. And the hair damage was also evaluated by the protein release ability and SEM of hair. The bleached hair immediately after permanent setting treatment has better wave formation ability, but much more damaged than the bleached hair after rinsing thoroughly with warm water. It was considered that the chain of hair keratin broke down easily by the bleaching action in the existence of permanent setting agents.

An attempt was made to synthesize an adsorbent by the photoinduced grafting of acrylic acid (AA) onto polypropylene nonwoven fabrics using benzophenone (BP) as a photosensitizer in a CH 3 OH/H 2 O medium. As the BP concentration was increased, the graft yield was increased up to a specific value and then decreased, and the effect of AA concentration showed the same tendency. It was also found that the graft yield increased with the reaction time and temperature. The amounts of ammonia adsorbed onto polypropylene nonwoven fabrics grafted with AA (PP-g-AA) were dependent on the graft yield, adsorption time, and ammonia gas pressure. The adsorption capacity of PP-g-AA was 5.86 mmol/g at the graft yield of 116.6%, which was much higher than that of active carbon or silica gel.