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An optimization study utilizing response surface methodology (RSM) and central composite design (CCD) was conducted to investigate batch foaming processes using supercritical CO2 as the physical blowing agent for neat polylactide (PLA) and polylactide/polyurethane (PLA/PU) blend foams. This study investigates the effect of single processing parameters on the properties of neat PLA foams. We demonstrate a complex interplay between foaming conditions and resulting foam properties, driven by competing effects of cell collapse and nucleation under varying temperatures, pressure, and time. Notably, thicker cell walls and higher sphericity, achieved through optimized foaming conditions, significantly enhance the foam’s compressive modulus and resistance to localized collapse. These findings underscore the critical role of processing parameters in tailoring the mechanical properties of PLA foams for diverse applications. Significant interactions between foaming process parameters were identified, impacting the properties of neat PLA foams. Foam density and average cell size exhibited an inverse relationship with foaming temperature and time. Initially, increases in both parameters decreased foam density and increased average cell size, attributed to enhanced gas dissolution at higher temperatures and longer durations, promoting rapid cell growth. Subsequent rises in these factors slightly increased foam density, possibly due to instability of foam structure and excessive gas diffusion. Compressive modulus was influenced by temperature and time, achieving the highest modulus at 50% strain under shorter foaming times and lower temperatures, facilitating rapid PLA solidification and smaller crystallite growth. Cell density decreased with rising temperature and pressure, likely from increased CO2 dissolution fostering more cell nuclei and reduced cell merging. Optimal lightweight PLA foams were obtained at 180°C, 165 bar, and 2.3 hours. Moreover, chemically recycled PLA, synth

Eumelanin as a natural pigment present several key functional properties that can protect human skin from ultraviolet (UV) light. Photoprotection ability that can absorb most of the UV light as a result of aromatic compounds in its structures has drawn vast interest to harness its excellent properties for various applications. Major drawbacks shown by organic molecules as UV absorber that limits their application includes their short lifespan. Encapsulation of the compound by various shell materials has been extensively studied to further optimize and extend its shielding efficiency from UV radiation. Polylactide (PLA)-based copolymers are widely used in encapsulation of various active compounds, due to their biocompatibility and biodegradability, promoting the sustained release of the active compounds. In this study, stereocomplex PLA (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLAb-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA, was employed in the encapsulation of eumelanin. An oil in water emulsion (O/W) approach followed by solvent evaporation was performed in encapsulation process. Effect of eumelanin distribution in PLA’s enantiomers and ultrasonication on physicochemical properties, encapsulation efficiency, and release behavior of nano/microparticles was evaluated. The potential application of the resulting particles for sunscreen was also examined by measuring the UV absorbance and in vitro sun protection factor (SPF) of sunscreen containing particles in the UVA-UVB region. FTIR spectra of the particles show characteristic peaks of sc-PLA with the changes in the intensity of significant peaks that correspond to eumelanin, denoting the success of the encapsulation process. Morphological image analysis reveals that the resulting particles have spherical shaped with the particle size that can be controlled by applying ultrasonication. Distribution of eumelanin in copolymer and ultrasonication process promote the g

Greenhouse gas reduction from large point sources has been of interest for global warming mitigation. Coal-fired power plants with carbon capture and utilization (CCU) technology can minimize carbon emissions. In this study, Life Cycle Assessment (LCA) methodology is applied to evaluate the potential environmental risks of capturing carbon dioxide at the coal-fired power plant in Thailand and utilizing it in alternative methanol (CO2_MeOH) and formic acid (CO2_FA) productions through direct CO2 hydrogenation. The study aims to achieve low carbon growth and sustainable development success in Thailand. According to the analyses, the negative carbon feedstock provides larger decarbonization in the CO2-based productions than the conventional productions (i.e., -862 vs. 712 kgCO2-eq in a ton of MeOH production while 1.96E3 vs. 4.11E3 kgCO2-eq in a ton of FA production). Despite the net negative carbon emissions, CO2_MeOH production can rise 6 out of 8 investigated environmental impact indicators, when 2 out of those would increase in CO2_FA production. The maximum impact scores as a result of the energy demand of the carbon capture can be reduced by integrating the waste heat recovery from the carbon removal process. Consequently, the higher impacts would be 4 out of 8 indicators in the CO2_MeOH production, whereas the CO2_FA production remains the same pattern. Furthermore, the investment costs of CCU projects are estimated on a unit price basis to strengthen an economy with a clean energy transition. The findings revealed that the process with the waste heat integration could decrease not only the related environmental risks but also the investment cost. However, total production costs (1227 $/tCO2_MeOH & 1044 $/tCO2_FA) are still expensive to compete with the conventional production prices (295-368 $/tMeOH & 546 $/tFA) and the current global market prices (750 $/tMeOH & 500-800 $/tFA), that could be lowered if low electricity cost was available. Selling by-product oxy

Greenhouse gas reduction from large point sources has been of interest for global warming mitigation. Coal-fired power plants with carbon capture and utilization (CCU) technology can minimize carbon emissions. In this study, Life Cycle Assessment (LCA) methodology is applied to evaluate the potential environmental risks of capturing carbon dioxide at the coal-fired power plant in Thailand and utilizing it in alternative methanol (CO2_MeOH) and formic acid (CO2_FA) productions through direct CO2 hydrogenation. The study aims to achieve low carbon growth and sustainable development success in Thailand. According to the analyses, the negative carbon feedstock provides larger decarbonization in the CO2-based productions than the conventional productions (i.e., -862 vs. 712 kgCO2-eq in a ton of MeOH production while 1.96E3 vs. 4.11E3 kgCO2-eq in a ton of FA production). Despite the net negative carbon emissions, CO2_MeOH production can rise 6 out of 8 investigated environmental impact indicators, when 2 out of those would increase in CO2_FA production. The maximum impact scores as a result of the energy demand of the carbon capture can be reduced by integrating the waste heat recovery from the carbon removal process. Consequently, the higher impacts would be 4 out of 8 indicators in the CO2_MeOH production, whereas the CO2_FA production remains the same pattern. Furthermore, the investment costs of CCU projects are estimated on a unit price basis to strengthen an economy with a clean energy transition. The findings revealed that the process with the waste heat integration could decrease not only the related environmental risks but also the investment cost. However, total production costs (1227 $/tCO2_MeOH & 1044 $/tCO2_FA) are still expensive to compete with the conventional production prices (295-368 $/tMeOH & 546 $/tFA) and the current global market prices (750 $/tMeOH & 500-800 $/tFA), that could be lowered if low electricity cost was available. Selling by-product oxy

Eumelanin as a natural pigment present several key functional properties that can protect human skin from ultraviolet (UV) light. Photoprotection ability that can absorb most of the UV light as a result of aromatic compounds in its structures has drawn vast interest to harness its excellent properties for various applications. Major drawbacks shown by organic molecules as UV absorber that limits their application includes their short lifespan. Encapsulation of the compound by various shell materials has been extensively studied to further optimize and extend its shielding efficiency from UV radiation. Polylactide (PLA)-based copolymers are widely used in encapsulation of various active compounds, due to their biocompatibility and biodegradability, promoting the sustained release of the active compounds. In this study, stereocomplex PLA (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLAb-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA, was employed in the encapsulation of eumelanin. An oil in water emulsion (O/W) approach followed by solvent evaporation was performed in encapsulation process. Effect of eumelanin distribution in PLA’s enantiomers and ultrasonication on physicochemical properties, encapsulation efficiency, and release behavior of nano/microparticles was evaluated. The potential application of the resulting particles for sunscreen was also examined by measuring the UV absorbance and in vitro sun protection factor (SPF) of sunscreen containing particles in the UVA-UVB region. FTIR spectra of the particles show characteristic peaks of sc-PLA with the changes in the intensity of significant peaks that correspond to eumelanin, denoting the success of the encapsulation process. Morphological image analysis reveals that the resulting particles have spherical shaped with the particle size that can be controlled by applying ultrasonication. Distribution of eumelanin in copolymer and ultrasonication process promote the g

Eumelanin as a natural pigment present several key functional properties that can protect human skin from ultraviolet (UV) light. Photoprotection ability that can absorb most of the UV light as a result of aromatic compounds in its structures has drawn vast interest to harness its excellent properties for various applications. Major drawbacks shown by organic molecules as UV absorber that limits their application includes their short lifespan. Encapsulation of the compound by various shell materials has been extensively studied to further optimize and extend its shielding efficiency from UV radiation. Polylactide (PLA)-based copolymers are widely used in encapsulation of various active compounds, due to their biocompatibility and biodegradability, promoting the sustained release of the active compounds. In this study, stereocomplex PLA (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLAb-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA, was employed in the encapsulation of eumelanin. An oil in water emulsion (O/W) approach followed by solvent evaporation was performed in encapsulation process. Effect of eumelanin distribution in PLA’s enantiomers and ultrasonication on physicochemical properties, encapsulation efficiency, and release behavior of nano/microparticles was evaluated. The potential application of the resulting particles for sunscreen was also examined by measuring the UV absorbance and in vitro sun protection factor (SPF) of sunscreen containing particles in the UVA-UVB region. FTIR spectra of the particles show characteristic peaks of sc-PLA with the changes in the intensity of significant peaks that correspond to eumelanin, denoting the success of the encapsulation process. Morphological image analysis reveals that the resulting particles have spherical shaped with the particle size that can be controlled by applying ultrasonication. Distribution of eumelanin in copolymer and ultrasonication process promote the g

Greenhouse gas reduction from large point sources has been of interest for global warming mitigation. Coal-fired power plants with carbon capture and utilization (CCU) technology can minimize carbon emissions. In this study, Life Cycle Assessment (LCA) methodology is applied to evaluate the potential environmental risks of capturing carbon dioxide at the coal-fired power plant in Thailand and utilizing it in alternative methanol (CO2_MeOH) and formic acid (CO2_FA) productions through direct CO2 hydrogenation. The study aims to achieve low carbon growth and sustainable development success in Thailand. According to the analyses, the negative carbon feedstock provides larger decarbonization in the CO2-based productions than the conventional productions (i.e., -862 vs. 712 kgCO2-eq in a ton of MeOH production while 1.96E3 vs. 4.11E3 kgCO2-eq in a ton of FA production). Despite the net negative carbon emissions, CO2_MeOH production can rise 6 out of 8 investigated environmental impact indicators, when 2 out of those would increase in CO2_FA production. The maximum impact scores as a result of the energy demand of the carbon capture can be reduced by integrating the waste heat recovery from the carbon removal process. Consequently, the higher impacts would be 4 out of 8 indicators in the CO2_MeOH production, whereas the CO2_FA production remains the same pattern. Furthermore, the investment costs of CCU projects are estimated on a unit price basis to strengthen an economy with a clean energy transition. The findings revealed that the process with the waste heat integration could decrease not only the related environmental risks but also the investment cost. However, total production costs (1227 $/tCO2_MeOH & 1044 $/tCO2_FA) are still expensive to compete with the conventional production prices (295-368 $/tMeOH & 546 $/tFA) and the current global market prices (750 $/tMeOH & 500-800 $/tFA), that could be lowered if low electricity cost was available. Selling by-product oxy

Eumelanin as a natural pigment present several key functional properties that can protect human skin from ultraviolet (UV) light. Photoprotection ability that can absorb most of the UV light as a result of aromatic compounds in its structures has drawn vast interest to harness its excellent properties for various applications. Major drawbacks shown by organic molecules as UV absorber that limits their application includes their short lifespan. Encapsulation of the compound by various shell materials has been extensively studied to further optimize and extend its shielding efficiency from UV radiation. Polylactide (PLA)-based copolymers are widely used in encapsulation of various active compounds, due to their biocompatibility and biodegradability, promoting the sustained release of the active compounds. In this study, stereocomplex PLA (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLAb-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA, was employed in the encapsulation of eumelanin. An oil in water emulsion (O/W) approach followed by solvent evaporation was performed in encapsulation process. Effect of eumelanin distribution in PLA’s enantiomers and ultrasonication on physicochemical properties, encapsulation efficiency, and release behavior of nano/microparticles was evaluated. The potential application of the resulting particles for sunscreen was also examined by measuring the UV absorbance and in vitro sun protection factor (SPF) of sunscreen containing particles in the UVA-UVB region. FTIR spectra of the particles show characteristic peaks of sc-PLA with the changes in the intensity of significant peaks that correspond to eumelanin, denoting the success of the encapsulation process. Morphological image analysis reveals that the resulting particles have spherical shaped with the particle size that can be controlled by applying ultrasonication. Distribution of eumelanin in copolymer and ultrasonication process promote the g

Greenhouse gas reduction from large point sources has been of interest for global warming mitigation. Coal-fired power plants with carbon capture and utilization (CCU) technology can minimize carbon emissions. In this study, Life Cycle Assessment (LCA) methodology is applied to evaluate the potential environmental risks of capturing carbon dioxide at the coal-fired power plant in Thailand and utilizing it in alternative methanol (CO2_MeOH) and formic acid (CO2_FA) productions through direct CO2 hydrogenation. The study aims to achieve low carbon growth and sustainable development success in Thailand. According to the analyses, the negative carbon feedstock provides larger decarbonization in the CO2-based productions than the conventional productions (i.e., -862 vs. 712 kgCO2-eq in a ton of MeOH production while 1.96E3 vs. 4.11E3 kgCO2-eq in a ton of FA production). Despite the net negative carbon emissions, CO2_MeOH production can rise 6 out of 8 investigated environmental impact indicators, when 2 out of those would increase in CO2_FA production. The maximum impact scores as a result of the energy demand of the carbon capture can be reduced by integrating the waste heat recovery from the carbon removal process. Consequently, the higher impacts would be 4 out of 8 indicators in the CO2_MeOH production, whereas the CO2_FA production remains the same pattern. Furthermore, the investment costs of CCU projects are estimated on a unit price basis to strengthen an economy with a clean energy transition. The findings revealed that the process with the waste heat integration could decrease not only the related environmental risks but also the investment cost. However, total production costs (1227 $/tCO2_MeOH & 1044 $/tCO2_FA) are still expensive to compete with the conventional production prices (295-368 $/tMeOH & 546 $/tFA) and the current global market prices (750 $/tMeOH & 500-800 $/tFA), that could be lowered if low electricity cost was available. Selling by-product oxy

Eumelanin as a natural pigment present several key functional properties that can protect human skin from ultraviolet (UV) light. Photoprotection ability that can absorb most of the UV light as a result of aromatic compounds in its structures has drawn vast interest to harness its excellent properties for various applications. Major drawbacks shown by organic molecules as UV absorber that limits their application includes their short lifespan. Encapsulation of the compound by various shell materials has been extensively studied to further optimize and extend its shielding efficiency from UV radiation. Polylactide (PLA)-based copolymers are widely used in encapsulation of various active compounds, due to their biocompatibility and biodegradability, promoting the sustained release of the active compounds. In this study, stereocomplex PLA (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLAb-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA, was employed in the encapsulation of eumelanin. An oil in water emulsion (O/W) approach followed by solvent evaporation was performed in encapsulation process. Effect of eumelanin distribution in PLA’s enantiomers and ultrasonication on physicochemical properties, encapsulation efficiency, and release behavior of nano/microparticles was evaluated. The potential application of the resulting particles for sunscreen was also examined by measuring the UV absorbance and in vitro sun protection factor (SPF) of sunscreen containing particles in the UVA-UVB region. FTIR spectra of the particles show characteristic peaks of sc-PLA with the changes in the intensity of significant peaks that correspond to eumelanin, denoting the success of the encapsulation process. Morphological image analysis reveals that the resulting particles have spherical shaped with the particle size that can be controlled by applying ultrasonication. Distribution of eumelanin in copolymer and ultrasonication process promote the g

Greenhouse gas reduction from large point sources has been of interest for global warming mitigation. Coal-fired power plants with carbon capture and utilization (CCU) technology can minimize carbon emissions. In this study, Life Cycle Assessment (LCA) methodology is applied to evaluate the potential environmental risks of capturing carbon dioxide at the coal-fired power plant in Thailand and utilizing it in alternative methanol (CO2_MeOH) and formic acid (CO2_FA) productions through direct CO2 hydrogenation. The study aims to achieve low carbon growth and sustainable development success in Thailand. According to the analyses, the negative carbon feedstock provides larger decarbonization in the CO2-based productions than the conventional productions (i.e., -862 vs. 712 kgCO2-eq in a ton of MeOH production while 1.96E3 vs. 4.11E3 kgCO2-eq in a ton of FA production). Despite the net negative carbon emissions, CO2_MeOH production can rise 6 out of 8 investigated environmental impact indicators, when 2 out of those would increase in CO2_FA production. The maximum impact scores as a result of the energy demand of the carbon capture can be reduced by integrating the waste heat recovery from the carbon removal process. Consequently, the higher impacts would be 4 out of 8 indicators in the CO2_MeOH production, whereas the CO2_FA production remains the same pattern. Furthermore, the investment costs of CCU projects are estimated on a unit price basis to strengthen an economy with a clean energy transition. The findings revealed that the process with the waste heat integration could decrease not only the related environmental risks but also the investment cost. However, total production costs (1227 $/tCO2_MeOH & 1044 $/tCO2_FA) are still expensive to compete with the conventional production prices (295-368 $/tMeOH & 546 $/tFA) and the current global market prices (750 $/tMeOH & 500-800 $/tFA), that could be lowered if low electricity cost was available. Selling by-product oxy

Quaternized carboxymethyl chitosan (QCMC), a polyampholyte with the presence of both negative charge and positive charge on two sides of chitosan backbone, has attached vast attentions for its high potential in applications, such as water purification, drug delivery, cancer treatment, antioxidant, moisture-absorption and retention agents in cosmetic applications. However, highly toxic monochloroacetic agents, as well as hard conditions are required to produce QCMC. A promising "green" alternative method to introduce negative charges to chitosan is to directly oxidize chitosan by (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) in a presence of co-oxidants, such as NaOCl/NaBr, NaOCl2, or O2/laccase. Although TEMPO is well-known as effective catalyst for "green" oxidation of primary alcohols, its co-oxidants impose concerns for their impacts to the environment as well as their cost. Hence, this study aims to develop a "green", halide-free, and cost-affordable process to prepare charged chitosan derivatives, such as quaternized chitosan (QCs), oxidized chitosan (OCs), and chitosan polyampholyte (CPAs). In addition, insights into the oxidation reaction mechanisms are investigated. Chitosan was initially grafted by glycidyl trimethyl ammonium chloride (GTMAC) in aqueous solutions at 60 °C for 24 h to obtain QCs. The quaternization degree (QD) and solubility of QCs was optimized by varying molar ratios of GTMAC and NH2 groups on chitosan. Oxoammonium cation (TEMPO+), a main oxidant formed in situ in the oxidation reaction of TEMPO and co-oxidants, was synthesized by ozone oxidation of TEMPO at 4-5 °C in 0.05M H2SO4 solution. The conversion mechanism of TEMPO to TEMPO+ was investigated by UV-Vis spectroscopy and 2D UV-Vis spectroscopy correlation analysis. The optimized conditions of TEMPO+ formation, the stoichiometry molar ratio of TEMPO+ and the consumed TEMPO under different supplied ozone contents and reaction times were determined by UV-Vis spectroscopy and iodometri

Chemical recycling of post-consumer bioplastic wastes, especially polyesters, has been of interest for recovering of small-sized products for use as value-added starting materials in other processes. Alcoholysis or transesterification of polylactide (PLA) with various alcohols and polymers, i.e., 1,2-ethanediol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,2-propanediol (PG), glycerol, erythritol, xylitol, sorbitol, poly(ethylene glycol) (PEG), and poly (propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PGEG), is developed by using microwave reactor, in a presence of tetrabutyl orthotitanate (TBT) catalyst at various PLA/alcohol ratios. The alcoholyzed products were characterized by employing Fourier transform infrared (FTIR) spectroscopy, two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The products compost of diol-capped lactate sequences with different length, i.e., lactate, dilactate, and polylactate. Monolactate is obtained at much higher contents than those of dilactate and polylactate, when excess amount of alcohols was used at a PLA/alcohol ratio of 1:1 wt/wt. However, monolactate content is decreased by changing the PLA/alcohol ratios from 1:1 to 4:1 wt/wt. In contrast, dilactate and polylactate contents are increased with an increase in the PLA/alcohol ratios. Efficiency and reactivity of the alcohols, in reacting and bonding with lactate sequences at a PLA/alcohol ratio of 1:1, are observed in an order, as follows: EG > PDO > PG > erythritol > glycerol > BDO > xylitol > sorbitol. An alcoholysis of PLA by high molecular weight PEG and PGEG produces only oligo-lactate sequences with different chain lengths. Interestingly, the alcoholysis of PLA also generates lactide from the chain’s back-biting reaction, whose content is increased by an increase in the PLA/alcohol ratios from 1:1 to 20:1 wt/wt. The alcoholyzed PLA products, with specific size and

Chemical recycling of post-consumer bioplastic wastes, especially polyesters, has been of interest for recovering of small-sized products for use as value-added starting materials in other processes. Alcoholysis or transesterification of polylactide (PLA) with various alcohols and polymers, i.e., 1,2-ethanediol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,2-propanediol (PG), glycerol, erythritol, xylitol, sorbitol, poly(ethylene glycol) (PEG), and poly (propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PGEG), is developed by using microwave reactor, in a presence of tetrabutyl orthotitanate (TBT) catalyst at various PLA/alcohol ratios. The alcoholyzed products were characterized by employing Fourier transform infrared (FTIR) spectroscopy, two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The products compost of diol-capped lactate sequences with different length, i.e., lactate, dilactate, and polylactate. Monolactate is obtained at much higher contents than those of dilactate and polylactate, when excess amount of alcohols was used at a PLA/alcohol ratio of 1:1 wt/wt. However, monolactate content is decreased by changing the PLA/alcohol ratios from 1:1 to 4:1 wt/wt. In contrast, dilactate and polylactate contents are increased with an increase in the PLA/alcohol ratios. Efficiency and reactivity of the alcohols, in reacting and bonding with lactate sequences at a PLA/alcohol ratio of 1:1, are observed in an order, as follows: EG > PDO > PG > erythritol > glycerol > BDO > xylitol > sorbitol. An alcoholysis of PLA by high molecular weight PEG and PGEG produces only oligo-lactate sequences with different chain lengths. Interestingly, the alcoholysis of PLA also generates lactide from the chain’s back-biting reaction, whose content is increased by an increase in the PLA/alcohol ratios from 1:1 to 20:1 wt/wt. The alcoholyzed PLA products, with specific size and

Quaternized carboxymethyl chitosan (QCMC), a polyampholyte with the presence of both negative charge and positive charge on two sides of chitosan backbone, has attached vast attentions for its high potential in applications, such as water purification, drug delivery, cancer treatment, antioxidant, moisture-absorption and retention agents in cosmetic applications. However, highly toxic monochloroacetic agents, as well as hard conditions are required to produce QCMC. A promising "green" alternative method to introduce negative charges to chitosan is to directly oxidize chitosan by (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) in a presence of co-oxidants, such as NaOCl/NaBr, NaOCl2, or O2/laccase. Although TEMPO is well-known as effective catalyst for "green" oxidation of primary alcohols, its co-oxidants impose concerns for their impacts to the environment as well as their cost. Hence, this study aims to develop a "green", halide-free, and cost-affordable process to prepare charged chitosan derivatives, such as quaternized chitosan (QCs), oxidized chitosan (OCs), and chitosan polyampholyte (CPAs). In addition, insights into the oxidation reaction mechanisms are investigated. Chitosan was initially grafted by glycidyl trimethyl ammonium chloride (GTMAC) in aqueous solutions at 60 °C for 24 h to obtain QCs. The quaternization degree (QD) and solubility of QCs was optimized by varying molar ratios of GTMAC and NH2 groups on chitosan. Oxoammonium cation (TEMPO+), a main oxidant formed in situ in the oxidation reaction of TEMPO and co-oxidants, was synthesized by ozone oxidation of TEMPO at 4-5 °C in 0.05M H2SO4 solution. The conversion mechanism of TEMPO to TEMPO+ was investigated by UV-Vis spectroscopy and 2D UV-Vis spectroscopy correlation analysis. The optimized conditions of TEMPO+ formation, the stoichiometry molar ratio of TEMPO+ and the consumed TEMPO under different supplied ozone contents and reaction times were determined by UV-Vis spectroscopy and iodometri

Quaternized carboxymethyl chitosan (QCMC), a polyampholyte with the presence of both negative charge and positive charge on two sides of chitosan backbone, has attached vast attentions for its high potential in applications, such as water purification, drug delivery, cancer treatment, antioxidant, moisture-absorption and retention agents in cosmetic applications. However, highly toxic monochloroacetic agents, as well as hard conditions are required to produce QCMC. A promising "green" alternative method to introduce negative charges to chitosan is to directly oxidize chitosan by (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) in a presence of co-oxidants, such as NaOCl/NaBr, NaOCl2, or O2/laccase. Although TEMPO is well-known as effective catalyst for "green" oxidation of primary alcohols, its co-oxidants impose concerns for their impacts to the environment as well as their cost. Hence, this study aims to develop a "green", halide-free, and cost-affordable process to prepare charged chitosan derivatives, such as quaternized chitosan (QCs), oxidized chitosan (OCs), and chitosan polyampholyte (CPAs). In addition, insights into the oxidation reaction mechanisms are investigated. Chitosan was initially grafted by glycidyl trimethyl ammonium chloride (GTMAC) in aqueous solutions at 60 °C for 24 h to obtain QCs. The quaternization degree (QD) and solubility of QCs was optimized by varying molar ratios of GTMAC and NH2 groups on chitosan. Oxoammonium cation (TEMPO+), a main oxidant formed in situ in the oxidation reaction of TEMPO and co-oxidants, was synthesized by ozone oxidation of TEMPO at 4-5 °C in 0.05M H2SO4 solution. The conversion mechanism of TEMPO to TEMPO+ was investigated by UV-Vis spectroscopy and 2D UV-Vis spectroscopy correlation analysis. The optimized conditions of TEMPO+ formation, the stoichiometry molar ratio of TEMPO+ and the consumed TEMPO under different supplied ozone contents and reaction times were determined by UV-Vis spectroscopy and iodometri

Chemical recycling of post-consumer bioplastic wastes, especially polyesters, has been of interest for recovering of small-sized products for use as value-added starting materials in other processes. Alcoholysis or transesterification of polylactide (PLA) with various alcohols and polymers, i.e., 1,2-ethanediol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,2-propanediol (PG), glycerol, erythritol, xylitol, sorbitol, poly(ethylene glycol) (PEG), and poly (propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PGEG), is developed by using microwave reactor, in a presence of tetrabutyl orthotitanate (TBT) catalyst at various PLA/alcohol ratios. The alcoholyzed products were characterized by employing Fourier transform infrared (FTIR) spectroscopy, two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The products compost of diol-capped lactate sequences with different length, i.e., lactate, dilactate, and polylactate. Monolactate is obtained at much higher contents than those of dilactate and polylactate, when excess amount of alcohols was used at a PLA/alcohol ratio of 1:1 wt/wt. However, monolactate content is decreased by changing the PLA/alcohol ratios from 1:1 to 4:1 wt/wt. In contrast, dilactate and polylactate contents are increased with an increase in the PLA/alcohol ratios. Efficiency and reactivity of the alcohols, in reacting and bonding with lactate sequences at a PLA/alcohol ratio of 1:1, are observed in an order, as follows: EG > PDO > PG > erythritol > glycerol > BDO > xylitol > sorbitol. An alcoholysis of PLA by high molecular weight PEG and PGEG produces only oligo-lactate sequences with different chain lengths. Interestingly, the alcoholysis of PLA also generates lactide from the chain’s back-biting reaction, whose content is increased by an increase in the PLA/alcohol ratios from 1:1 to 20:1 wt/wt. The alcoholyzed PLA products, with specific size and

Chemical recycling of post-consumer bioplastic wastes, especially polyesters, has been of interest for recovering of small-sized products for use as value-added starting materials in other processes. Alcoholysis or transesterification of polylactide (PLA) with various alcohols and polymers, i.e., 1,2-ethanediol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,2-propanediol (PG), glycerol, erythritol, xylitol, sorbitol, poly(ethylene glycol) (PEG), and poly (propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PGEG), is developed by using microwave reactor, in a presence of tetrabutyl orthotitanate (TBT) catalyst at various PLA/alcohol ratios. The alcoholyzed products were characterized by employing Fourier transform infrared (FTIR) spectroscopy, two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The products compost of diol-capped lactate sequences with different length, i.e., lactate, dilactate, and polylactate. Monolactate is obtained at much higher contents than those of dilactate and polylactate, when excess amount of alcohols was used at a PLA/alcohol ratio of 1:1 wt/wt. However, monolactate content is decreased by changing the PLA/alcohol ratios from 1:1 to 4:1 wt/wt. In contrast, dilactate and polylactate contents are increased with an increase in the PLA/alcohol ratios. Efficiency and reactivity of the alcohols, in reacting and bonding with lactate sequences at a PLA/alcohol ratio of 1:1, are observed in an order, as follows: EG > PDO > PG > erythritol > glycerol > BDO > xylitol > sorbitol. An alcoholysis of PLA by high molecular weight PEG and PGEG produces only oligo-lactate sequences with different chain lengths. Interestingly, the alcoholysis of PLA also generates lactide from the chain’s back-biting reaction, whose content is increased by an increase in the PLA/alcohol ratios from 1:1 to 20:1 wt/wt. The alcoholyzed PLA products, with specific size and

Quaternized carboxymethyl chitosan (QCMC), a polyampholyte with the presence of both negative charge and positive charge on two sides of chitosan backbone, has attached vast attentions for its high potential in applications, such as water purification, drug delivery, cancer treatment, antioxidant, moisture-absorption and retention agents in cosmetic applications. However, highly toxic monochloroacetic agents, as well as hard conditions are required to produce QCMC. A promising "green" alternative method to introduce negative charges to chitosan is to directly oxidize chitosan by (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) in a presence of co-oxidants, such as NaOCl/NaBr, NaOCl2, or O2/laccase. Although TEMPO is well-known as effective catalyst for "green" oxidation of primary alcohols, its co-oxidants impose concerns for their impacts to the environment as well as their cost. Hence, this study aims to develop a "green", halide-free, and cost-affordable process to prepare charged chitosan derivatives, such as quaternized chitosan (QCs), oxidized chitosan (OCs), and chitosan polyampholyte (CPAs). In addition, insights into the oxidation reaction mechanisms are investigated. Chitosan was initially grafted by glycidyl trimethyl ammonium chloride (GTMAC) in aqueous solutions at 60 °C for 24 h to obtain QCs. The quaternization degree (QD) and solubility of QCs was optimized by varying molar ratios of GTMAC and NH2 groups on chitosan. Oxoammonium cation (TEMPO+), a main oxidant formed in situ in the oxidation reaction of TEMPO and co-oxidants, was synthesized by ozone oxidation of TEMPO at 4-5 °C in 0.05M H2SO4 solution. The conversion mechanism of TEMPO to TEMPO+ was investigated by UV-Vis spectroscopy and 2D UV-Vis spectroscopy correlation analysis. The optimized conditions of TEMPO+ formation, the stoichiometry molar ratio of TEMPO+ and the consumed TEMPO under different supplied ozone contents and reaction times were determined by UV-Vis spectroscopy and iodometri

Chemical recycling of post-consumer bioplastic wastes, especially polyesters, has been of interest for recovering of small-sized products for use as value-added starting materials in other processes. Alcoholysis or transesterification of polylactide (PLA) with various alcohols and polymers, i.e., 1,2-ethanediol (EG), 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,2-propanediol (PG), glycerol, erythritol, xylitol, sorbitol, poly(ethylene glycol) (PEG), and poly (propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PGEG), is developed by using microwave reactor, in a presence of tetrabutyl orthotitanate (TBT) catalyst at various PLA/alcohol ratios. The alcoholyzed products were characterized by employing Fourier transform infrared (FTIR) spectroscopy, two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The products compost of diol-capped lactate sequences with different length, i.e., lactate, dilactate, and polylactate. Monolactate is obtained at much higher contents than those of dilactate and polylactate, when excess amount of alcohols was used at a PLA/alcohol ratio of 1:1 wt/wt. However, monolactate content is decreased by changing the PLA/alcohol ratios from 1:1 to 4:1 wt/wt. In contrast, dilactate and polylactate contents are increased with an increase in the PLA/alcohol ratios. Efficiency and reactivity of the alcohols, in reacting and bonding with lactate sequences at a PLA/alcohol ratio of 1:1, are observed in an order, as follows: EG > PDO > PG > erythritol > glycerol > BDO > xylitol > sorbitol. An alcoholysis of PLA by high molecular weight PEG and PGEG produces only oligo-lactate sequences with different chain lengths. Interestingly, the alcoholysis of PLA also generates lactide from the chain’s back-biting reaction, whose content is increased by an increase in the PLA/alcohol ratios from 1:1 to 20:1 wt/wt. The alcoholyzed PLA products, with specific size and

Quaternized carboxymethyl chitosan (QCMC), a polyampholyte with the presence of both negative charge and positive charge on two sides of chitosan backbone, has attached vast attentions for its high potential in applications, such as water purification, drug delivery, cancer treatment, antioxidant, moisture-absorption and retention agents in cosmetic applications. However, highly toxic monochloroacetic agents, as well as hard conditions are required to produce QCMC. A promising "green" alternative method to introduce negative charges to chitosan is to directly oxidize chitosan by (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) in a presence of co-oxidants, such as NaOCl/NaBr, NaOCl2, or O2/laccase. Although TEMPO is well-known as effective catalyst for "green" oxidation of primary alcohols, its co-oxidants impose concerns for their impacts to the environment as well as their cost. Hence, this study aims to develop a "green", halide-free, and cost-affordable process to prepare charged chitosan derivatives, such as quaternized chitosan (QCs), oxidized chitosan (OCs), and chitosan polyampholyte (CPAs). In addition, insights into the oxidation reaction mechanisms are investigated. Chitosan was initially grafted by glycidyl trimethyl ammonium chloride (GTMAC) in aqueous solutions at 60 °C for 24 h to obtain QCs. The quaternization degree (QD) and solubility of QCs was optimized by varying molar ratios of GTMAC and NH2 groups on chitosan. Oxoammonium cation (TEMPO+), a main oxidant formed in situ in the oxidation reaction of TEMPO and co-oxidants, was synthesized by ozone oxidation of TEMPO at 4-5 °C in 0.05M H2SO4 solution. The conversion mechanism of TEMPO to TEMPO+ was investigated by UV-Vis spectroscopy and 2D UV-Vis spectroscopy correlation analysis. The optimized conditions of TEMPO+ formation, the stoichiometry molar ratio of TEMPO+ and the consumed TEMPO under different supplied ozone contents and reaction times were determined by UV-Vis spectroscopy and iodometri

Polymeric nanofibers with super-hydrophobic properties have high potential in many applications, due to their high water resistance and oil/water selectivity. Polylactide (PLA) is a prominent alternative to conventional polymers, owing to its biocompatibility and degradability. Super-hydrophobic PLA nanofibers, therefore, offer many advantages for use in biomedical and environmental-friendly applications. In this work, PLA nanofibers with super-hydrophobic properties have been prepared by an electrospinning technique and surface treating with hydrophobic agents. Glycerol and polyglycerol (PG) which possesses branched structures with multiple active OH end-groups (x-OH), was employed as templates for reacting with a fatty acid derivative, alkyl ketene dimer (AKD). The fibers were first electrospun using PLA/x-OH blend solutions in CHCl3/DMF mixed solvent, at a fixed composition of 5wt% x-OH. The resulting fibers were then dipped in AKD solution, followed by heating at elevated temperatures. The results indicated that fibers with super-hydrophobic properties were produced, with a water contact angle (WCA) of higher than 150o. SEM and ATR-FTIR spectroscopy were employed to verify surface morphology and chemical reactions on the fibers’ surface. The materials have a high potential for use as environmental-friendly filter meshes for oil absorption and oil/water separation.

Polymeric nanofibers with super-hydrophobic properties have high potential in many applications, due to their high water resistance and oil/water selectivity. Polylactide (PLA) is a prominent alternative to conventional polymers, owing to its biocompatibility and degradability. Super-hydrophobic PLA nanofibers, therefore, offer many advantages for use in biomedical and environmental-friendly applications. In this work, PLA nanofibers with super-hydrophobic properties have been prepared by an electrospinning technique and surface treating with hydrophobic agents. Glycerol and polyglycerol (PG) which possesses branched structures with multiple active OH end-groups (x-OH), was employed as templates for reacting with a fatty acid derivative, alkyl ketene dimer (AKD). The fibers were first electrospun using PLA/x-OH blend solutions in CHCl3/DMF mixed solvent, at a fixed composition of 5wt% x-OH. The resulting fibers were then dipped in AKD solution, followed by heating at elevated temperatures. The results indicated that fibers with super-hydrophobic properties were produced, with a water contact angle (WCA) of higher than 150o. SEM and ATR-FTIR spectroscopy were employed to verify surface morphology and chemical reactions on the fibers’ surface. The materials have a high potential for use as environmental-friendly filter meshes for oil absorption and oil/water separation.

Polymeric nanofibers with super-hydrophobic properties have high potential in many applications, due to their high water resistance and oil/water selectivity. Polylactide (PLA) is a prominent alternative to conventional polymers, owing to its biocompatibility and degradability. Super-hydrophobic PLA nanofibers, therefore, offer many advantages for use in biomedical and environmental-friendly applications. In this work, PLA nanofibers with super-hydrophobic properties have been prepared by an electrospinning technique and surface treating with hydrophobic agents. Glycerol and polyglycerol (PG) which possesses branched structures with multiple active OH end-groups (x-OH), was employed as templates for reacting with a fatty acid derivative, alkyl ketene dimer (AKD). The fibers were first electrospun using PLA/x-OH blend solutions in CHCl3/DMF mixed solvent, at a fixed composition of 5wt% x-OH. The resulting fibers were then dipped in AKD solution, followed by heating at elevated temperatures. The results indicated that fibers with super-hydrophobic properties were produced, with a water contact angle (WCA) of higher than 150o. SEM and ATR-FTIR spectroscopy were employed to verify surface morphology and chemical reactions on the fibers’ surface. The materials have a high potential for use as environmental-friendly filter meshes for oil absorption and oil/water separation.

Polymeric nanofibers with super-hydrophobic properties have high potential in many applications, due to their high water resistance and oil/water selectivity. Polylactide (PLA) is a prominent alternative to conventional polymers, owing to its biocompatibility and degradability. Super-hydrophobic PLA nanofibers, therefore, offer many advantages for use in biomedical and environmental-friendly applications. In this work, PLA nanofibers with super-hydrophobic properties have been prepared by an electrospinning technique and surface treating with hydrophobic agents. Glycerol and polyglycerol (PG) which possesses branched structures with multiple active OH end-groups (x-OH), was employed as templates for reacting with a fatty acid derivative, alkyl ketene dimer (AKD). The fibers were first electrospun using PLA/x-OH blend solutions in CHCl3/DMF mixed solvent, at a fixed composition of 5wt% x-OH. The resulting fibers were then dipped in AKD solution, followed by heating at elevated temperatures. The results indicated that fibers with super-hydrophobic properties were produced, with a water contact angle (WCA) of higher than 150o. SEM and ATR-FTIR spectroscopy were employed to verify surface morphology and chemical reactions on the fibers’ surface. The materials have a high potential for use as environmental-friendly filter meshes for oil absorption and oil/water separation.

Polymeric nanofibers with super-hydrophobic properties have high potential in many applications, due to their high water resistance and oil/water selectivity. Polylactide (PLA) is a prominent alternative to conventional polymers, owing to its biocompatibility and degradability. Super-hydrophobic PLA nanofibers, therefore, offer many advantages for use in biomedical and environmental-friendly applications. In this work, PLA nanofibers with super-hydrophobic properties have been prepared by an electrospinning technique and surface treating with hydrophobic agents. Glycerol and polyglycerol (PG) which possesses branched structures with multiple active OH end-groups (x-OH), was employed as templates for reacting with a fatty acid derivative, alkyl ketene dimer (AKD). The fibers were first electrospun using PLA/x-OH blend solutions in CHCl3/DMF mixed solvent, at a fixed composition of 5wt% x-OH. The resulting fibers were then dipped in AKD solution, followed by heating at elevated temperatures. The results indicated that fibers with super-hydrophobic properties were produced, with a water contact angle (WCA) of higher than 150o. SEM and ATR-FTIR spectroscopy were employed to verify surface morphology and chemical reactions on the fibers’ surface. The materials have a high potential for use as environmental-friendly filter meshes for oil absorption and oil/water separation.

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i