Monvisade, Pathavuth
Loading...
Preferred name
Monvisade, Pathavuth
Alternative Name
Monvisade, P.
Main Affiliation
Email
pathavuth.mo@kmitl.ac.th
8 results
Now showing 1 - 8 of 8
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Photocrosslinked Poly(Vinyl Alcohol)–Tung Oil–Natural Rubber Films: A Sustainable Solution for Enhanced Water Resistance and Mechanical Properties in Biodegradable Packaging(2025-06-20); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Study on Crosslinked Structure and Thermal Properties of Polymer Networks Based on Tung Oil and PVA with Different Catalytic Systems(2017-04-01); Yamaguchi, MasayukiThis work focuses on the effect of different catalytic systems on network structures and thermal properties of the polymer networks from poly(vinyl alcohol) (PVA) and Tung oil. The polymer networks based on Tung oil and PVA using potassium persulfate (KPS) as a thermal catalyst or KPS and sodium thiosulfate as a redox catalyst were performed at 60 °C and 80 °C. FTIR results confirmed that Tung oil could be crosslinked by both catalysts. Moreover, at 60 °C, it can be seen that the crosslinking reaction with the redox catalyst could occur better than with the thermal catalyst. To prove the crosslinking reaction of PVA in the polymer networks, water resistance of the polymer networks was also investigated. It was found that the PVA was successfully crosslinked by thermal catalyst but was not by redox catalyst. Besides, from this result, it could be suggested that, in the redox system, structure of the polymer networks was mainly formed by Tung oil. From DMA results, T<inf>g</inf> of PVA with the thermal catalyst is higher than that with the redox catalyst because of the network formation of PVA in thermal catalytic system. While the T<inf>g</inf> of Tung oil in the polymer networks with the redox catalyst is higher than that with the thermal catalyst. This is reasonable because the crosslinking reaction of Tung oil with the redox catalyst could easily occur better than with the thermal catalyst. Altogether, crosslink structure of Tung oil exhibited major influence on properties of PVA/Tung oil polymer network. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The effect of glycerol/water and sorbitol/water on the plasticization of hydroxyethylacryl chitosan/sodium alginate films(2015-11-04); Yamaguchi, MasayukiThis research aimed to investigate on the effects of glycerol/water and sorbitol/water on the plasticization of hydroxyethylacryl chitosan (HC)/sodium alginate (SA) films. The HC/SA films were prepared with different amount of glycerol or sorbitol as a plasticizer (25, 40 and 50% w/w) and kept at different relative humidity (0% RH and 50% RH) in order to restrict the content of water within the films. The results from differential scanning calorimetry (DSC) showed the miscibility of polymer and plasticizers (glycerol and sorbitol) for all blend compositions. A remarkable reduction of glass transition temperature (T<inf>g</inf>) could be obtained by adding glycerol over 40% w/w. For sorbitol plasticized films, although the addition of sorbitol could reduce T<inf>g</inf>, it was still higher than room temperature. It was claimed that glycerol could gain more effective plasticizing than sorbitol in the HC/SA films. In the cooperation with water as co-plasticizer (glycerol/water or sorbitol/water), the T<inf>g</inf> values of all films were dramatically decreased to -50 °C for glycerol/water plasticized films and down to 0 °C for sorbitol/water plasticized films. The reasonable flexible films could be obtained by the use of either glycerol/water or sorbitol/water as couple plasticizers. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dual covalent and ionic crosslinked xanthan gum–PVA hydrogel films for enhanced drug release performance(2025-11-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Development of hydroxyethylacryl chitosan/alginate hydrogel films for biomedical application(2014-12-01); Yamaguchi, MasayukiNovel hydrogel films composed of hydroxyethylacryl chitosan (HC) and sodium alginate (SA) were prepared for biomedical application by using calcium chloride (CaCl<inf>2</inf>) as a nontoxic ionic crosslinker to form a semi-interpenetrating polymer network (semi-IPN). HC was successfully prepared by following a Michael addition reaction of chitosan (CS) and hydroxyethylacrylate completely dissolved in distilled water at 70 °C. The distribution pattern of Ca<sup>2+</sup> ions were well-dispersed within the hydrogel films examined by scanning electron microscope-energy dispersive spectrometry (SEM-EDS), implying uniformity of crosslinking. The swelling behavior of the hydrogel films in distilled water, simulated gastric fluid (SGF, pH = 1.2) and phosphate buffer solution (PBS, pH = 7.4) were investigated. The equilibrium swelling degree of the hydrogel films in distilled water increased with a decreas of either the SA content or the concentration of CaCl<inf>2</inf>. The hydrogel films showed pH-dependent behavior in that the shapes of the hydrogel films were stable in SGF while they degraded in PBS. The tensile strength and elongation of the hydrogel films reached 12.1 MPa and 162%, respectively, which presented reasonable mechanical properties during use and enough flexibility to follow skin movement. Cell viability of the hydrogels was measured using a methylthiazol tetrazolium (MTT) assay. The results indicated that the hydrogel films are not cytotoxic. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancing Structural Stability and Drug Release Control in Xanthan Gum–Poly(vinyl alcohol) Hydrogel Films via Ferric Ion Crosslinking(2026-05-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Surface improvement on water and oil affinities and absorption rate of PVA/Tung oil-coated paperboard and fiberboard(2016-03-01); Yamaguchi, MasayukiA novel coating material on paperboard and fiberboard from poly(vinyl alcohol) (PVA) modified with Tung oil was developed. The PVA/Tung oil coating was cured at several conditions: 25, 40, 50, and 60°C, in the presence of two types of catalysts, i.e., thermal catalyst using potassium persulfate (KPS) and redox catalyst using KPS and sodium thiosulfate. The chemical crosslinked structure of PVA/Tung oil-coating films was confirmed by FTIR. The result indicated the decrease in the double bonds of Tung oil by crosslinking reaction, especially at 60°C. In comparison with the same curing temperature, the films with redox catalyst showed more reduction in the number of double bonds of Tung oil. DMA results of the PVA/Tung oil-coating materials with redox catalyst showed the lowering of the heights of both β transition peak of Tung oil and α transition peak of PVA. FTIR and DMA results confirmed the more efficient crosslinking reaction of redox catalytic system than that of the thermal catalytic system. The water resistance and mechanical properties of these coating materials exhibited better values as projected to higher curing temperature and redox catalyst. SEM images showed the smooth surface of PVA/Tung oil covered on the paperboards with ~72 µm in thickness. The contact angle of water or oil drop and dynamic change in contact angle on the surfaces of PVA/Tung oil-coated paperboards and fiberboards were investigated. The results show the contact angles for both water and oil were lower than those of the uncoated ones, indicating the improvement of water and oil affinities of the PVA/Tung oil-coating materials. The dynamic changes in contact angle of the coated ones also decreased, suggesting the reduction in water and oil absorption rates of these coated substrates. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Combination of Tung oil and natural rubber latex in PVA as water based coatings for paperboard application(2015-11-04); Yamaguchi, MasayukiThis research is focused on the preparation of the PVA/TO/NRL coatings for paperboard by using poly(vinyl alcohol) (PVA) as substance and blending with Tung oil (TO) and/or natural rubber latex (NRL) in order to enhance water resistance and dynamic mechanical properties. The effects of TO: NRL ratios on the structures were investigated by water resistance property and dynamic mechanical thermal analysis (DMA). The results showed that the water resistance property was improved by crosslinking of TO and film forming of NRL. The PVA/TO/NRL coating containing both TO and NRL gave better thermal behavior than those with only TO or NRL. For paperboard application, the PVA/TO/NRL coatings were applied on the paperboard to study water affinity and absorption rate on the coated surface. The rate of contact angle change of water on coated paperboards decreased depending on the ratios of TO and NRL.