The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption ...The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption in a positive way. Adsorption efficiency at higher concentrations, however, depends on the type of inorganic salts as well as the sequence of adding inorganic salts and starch to paper suspension.展开更多
Based on the sweet potato starch,cationic starch,acetic starch and cationic-acetic compoundedly modified starch were made through chemical denaturalization.The above three kinds of static rheological parameter and dyn...Based on the sweet potato starch,cationic starch,acetic starch and cationic-acetic compoundedly modified starch were made through chemical denaturalization.The above three kinds of static rheological parameter and dynamic rheological parameter were measured,respectively.The experimental result reveals that the thermal stability of starchy viscosity increases after chemical denaturalization.Under the condition of identical shearing rate,the shear stress of cationic-acetic ester compoundedly modified sweet potato starch paste is the largest among these kinds of sweet potato starch.This attributes to a phenomenon of shearing thinning.Furthermore,raw sweet potato starch has a larger gel intensity than that of modified starch.展开更多
This paper deals with the retention and drainage properties of the high substituted degree cationic starch (HCS) prepared by half-dry process. The experiments show that HCS has remarkable effects on filler retention a...This paper deals with the retention and drainage properties of the high substituted degree cationic starch (HCS) prepared by half-dry process. The experiments show that HCS has remarkable effects on filler retention and drainage in papermaking industry. With the degree of substitution (DS) of HCS increasing, the effects on filler retention and drainage increase. When the DS of HCS is 0.509 and the dosage is 0.08%, the freeness decreases about 12oSR and the filler retention is 79.82%.展开更多
Natural starch is an abundant and inexpensive polysaccharide biopolymer that is widely used as a surface-sizing agent in the paper industry.The surface sizing of paper improves its water and abrasion resistance,as wel...Natural starch is an abundant and inexpensive polysaccharide biopolymer that is widely used as a surface-sizing agent in the paper industry.The surface sizing of paper improves its water and abrasion resistance,as well as its physical strength and printing adaptability.However,natural starch presents some disadvantages,such as high viscosity,poor fluidity,poor filmforming properties,and easy coagulation.Therefore,starch is usually modified and blended with various components to achieve better sizing performance.This article reviews approaches for the surface sizing of paper and modification of starch using enzymes or chemical methods,such as oxidation,cationization,and graft copolymerization.This article also discusses the application of starch-based multiphase systems(obtained by blending starch with various components)as surface-sizing agents.展开更多
Adhesive capacity of quaternary ammonium starch and starch phosphate to the polyester / cotton fibers was studied by means roving method for the purpose of improving the sizing performance and decreasing the cost. By ...Adhesive capacity of quaternary ammonium starch and starch phosphate to the polyester / cotton fibers was studied by means roving method for the purpose of improving the sizing performance and decreasing the cost. By introducing different amount of quaternary ammonium or phosphate groups onto starch molecules, the modified starch with a series of defferent degree of substitution was prepared. Therefore the regularity of adhesive capacity, extended property and size-absorbing ability with the change in degree of substitution (DS) was obtained through the researches. The experiments demonstrate that the DS of the two modified starches show a marked influence upon the properties mentioned above. The starch phosphate is superior to quaternary ammonium starch as warp size for polyester / cotton yarns from the viewpoint of adhesive capacity and cost, although both of them are better than natural one. To improve the adhesive capacity to polyester / cotton fibers, DS≥0.027 is necessary for quaternary ammonium展开更多
Amphiphilic starch derivatives with high content of functional groups were prepared from potato starch using a one-pot synthesis method with a single reaction medium for the entire procedure. Potato starch was benzyla...Amphiphilic starch derivatives with high content of functional groups were prepared from potato starch using a one-pot synthesis method with a single reaction medium for the entire procedure. Potato starch was benzylated, followed by the introduction of hydroxypropyltrimethylammonium(HPMA) moieties without the purification of intermediates. The synthesis was performed under heterogeneous conditions, leading to the formation of benzyl 2-hydroxypropyltri methylammonium starch chloride(BnHPMAS) with a total degree of substitution(DS) of up to 1.4. This process improved the efficiency of the preparation of amphiphilic starch derivatives and reduced the time and resources consumed by avoiding a separation process and purification of the intermediate compounds.The DS of BnHPMAS was in the range of 0.36 to 1.4, which could be tuned by varying the molar ratio of the reagents to repeating unit or by changing the reaction temperature, time, and medium. The structure of the amphiphilic starches was characterized using elemental analysis, size exclusion chromatography,fourier transform infrared spectroscopy(FT-IR), and nuclear magnetic resonance(NMR) spectroscopy. Moreover, the surface tension and turbidity of the solutions of the products were measured for their potential application in the removal of dissolved and colloidal substances in paper cycling water.展开更多
There are many natural sources to obtain pharmaceutical grade starch, one of which is banana (<i><i><span style="font-family:Verdana;">Musa</span></i><span style="font-f...There are many natural sources to obtain pharmaceutical grade starch, one of which is banana (<i><i><span style="font-family:Verdana;">Musa</span></i><span style="font-family:Verdana;"> × </span><i><span style="font-family:Verdana;">paradisiaca L</span></i><span style="font-family:Verdana;">.</span></i>);nevertheless, the use of native starch has certain disadvantages compared to modified starches, whose disintegrating properties are better. In this study, starch extracted from rejected fruits of <i><i><span style="font-family:Verdana;">Musa</span></i><span style="font-family:Verdana;"> × </span><i><span style="font-family:Verdana;">paradisiaca L</span></i><span style="font-family:Verdana;">.</span></i>, was modified by acetylation, under the following optimized experimental conditions: 130 mL acetic anhydride, 3 mL sodium hydroxide 50% p/v for each 15 grams of native starch, at 123℃ during 3 hours. The reaction resulted in a modified green banana starch with twice as much swelling capacity compared to unmodified (native) starch;acetylation was verified by infrared spectroscopy and degree of substitution of acetyl groups by back titration. The dissolution profiles of Ibuprofen tablets <span style="font-family:Verdana;">made </span><span style="font-family:Verdana;">with</span><span> </span><span style="font-family:Verdana;">banana modified starch and commercial disintegrant, ha</span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> no differences according with their similarity factor</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""> <i><span style="font-family:Verdana;">f</span></i><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">. It is concluded that it is feasible to use green banana starch modified through acetylation as a pharmaceutical disintegrant.</span></span>展开更多
Bio-degradable cassava starch-based adhesives were produced from chemically gelatinized starch formulations. The varying combinations of process parameters applied include: concentration of gelatinization modifier, ma...Bio-degradable cassava starch-based adhesives were produced from chemically gelatinized starch formulations. The varying combinations of process parameters applied include: concentration of gelatinization modifier, mass % borax/starch, and temperature of reaction mixture. The physico-chemical parameters for characterizing the adhesive samples were viscosity, density, pH and bonding strength. The effects of the variation of process parameters on the quality of the adhesives were assessed using response surface (central composite) designs with 2 factors, to relate the highest adhesive quality with the optimal combination of process factors. The adhesives produced using HCl as the gelatinization modifier were of a higher quality than those produced using NaOH with one of the most important quality assessment parameters which is the bond strength being 22.31 kPa at 0.01 M and 20% mass borax/starch and 11.60 kPa at 0.01 M and 8% mass borax/starch for HCl and NaOH respectively. The experimental results demonstrated that the optimal temperature for the production of the adhesive was 85˚C.展开更多
This paper deals with the preparation of cationic starch with high degree of substitute by dry-process. The corn starch and the alkali catalyst are mixed in the mixer, then added the cationic etherifying agent (3-chlo...This paper deals with the preparation of cationic starch with high degree of substitute by dry-process. The corn starch and the alkali catalyst are mixed in the mixer, then added the cationic etherifying agent (3-chloro-2-hydroxypropyltrimethylammonium chloride). The reacting time is for 5 hours at the temperature of 70℃. The cationic starch with high degree of substitution is used as anionic charge neutralizing agents to improve filler retention in wet-end section of papermaking machine.展开更多
文摘The article is focused on the influence of inorganic salts on the adsorption of cationically modified starch to fibers. Results show that low concentrations of inorganic salts usually affect the process of adsorption in a positive way. Adsorption efficiency at higher concentrations, however, depends on the type of inorganic salts as well as the sequence of adding inorganic salts and starch to paper suspension.
基金Project(2007FJ1007) supported by the Science Foundation of Hunan Province,China
文摘Based on the sweet potato starch,cationic starch,acetic starch and cationic-acetic compoundedly modified starch were made through chemical denaturalization.The above three kinds of static rheological parameter and dynamic rheological parameter were measured,respectively.The experimental result reveals that the thermal stability of starchy viscosity increases after chemical denaturalization.Under the condition of identical shearing rate,the shear stress of cationic-acetic ester compoundedly modified sweet potato starch paste is the largest among these kinds of sweet potato starch.This attributes to a phenomenon of shearing thinning.Furthermore,raw sweet potato starch has a larger gel intensity than that of modified starch.
文摘This paper deals with the retention and drainage properties of the high substituted degree cationic starch (HCS) prepared by half-dry process. The experiments show that HCS has remarkable effects on filler retention and drainage in papermaking industry. With the degree of substitution (DS) of HCS increasing, the effects on filler retention and drainage increase. When the DS of HCS is 0.509 and the dosage is 0.08%, the freeness decreases about 12oSR and the filler retention is 79.82%.
基金This study was supported by National Natural Science Foundation of China(Nos.31800498,22078035)Natural Science Foundation of Liaoning Province of China(No.2019-BS-16)Open Fund of Jiangsu Provincial Key Laboratory of Pulp and Paper(No.KL201903).
文摘Natural starch is an abundant and inexpensive polysaccharide biopolymer that is widely used as a surface-sizing agent in the paper industry.The surface sizing of paper improves its water and abrasion resistance,as well as its physical strength and printing adaptability.However,natural starch presents some disadvantages,such as high viscosity,poor fluidity,poor filmforming properties,and easy coagulation.Therefore,starch is usually modified and blended with various components to achieve better sizing performance.This article reviews approaches for the surface sizing of paper and modification of starch using enzymes or chemical methods,such as oxidation,cationization,and graft copolymerization.This article also discusses the application of starch-based multiphase systems(obtained by blending starch with various components)as surface-sizing agents.
文摘Adhesive capacity of quaternary ammonium starch and starch phosphate to the polyester / cotton fibers was studied by means roving method for the purpose of improving the sizing performance and decreasing the cost. By introducing different amount of quaternary ammonium or phosphate groups onto starch molecules, the modified starch with a series of defferent degree of substitution was prepared. Therefore the regularity of adhesive capacity, extended property and size-absorbing ability with the change in degree of substitution (DS) was obtained through the researches. The experiments demonstrate that the DS of the two modified starches show a marked influence upon the properties mentioned above. The starch phosphate is superior to quaternary ammonium starch as warp size for polyester / cotton yarns from the viewpoint of adhesive capacity and cost, although both of them are better than natural one. To improve the adhesive capacity to polyester / cotton fibers, DS≥0.027 is necessary for quaternary ammonium
基金financially supported by National Natural Science Foundation of China (No. 21774036)State Key Laboratory of Pulp and Paper Engineering (No. 2017TS01)
文摘Amphiphilic starch derivatives with high content of functional groups were prepared from potato starch using a one-pot synthesis method with a single reaction medium for the entire procedure. Potato starch was benzylated, followed by the introduction of hydroxypropyltrimethylammonium(HPMA) moieties without the purification of intermediates. The synthesis was performed under heterogeneous conditions, leading to the formation of benzyl 2-hydroxypropyltri methylammonium starch chloride(BnHPMAS) with a total degree of substitution(DS) of up to 1.4. This process improved the efficiency of the preparation of amphiphilic starch derivatives and reduced the time and resources consumed by avoiding a separation process and purification of the intermediate compounds.The DS of BnHPMAS was in the range of 0.36 to 1.4, which could be tuned by varying the molar ratio of the reagents to repeating unit or by changing the reaction temperature, time, and medium. The structure of the amphiphilic starches was characterized using elemental analysis, size exclusion chromatography,fourier transform infrared spectroscopy(FT-IR), and nuclear magnetic resonance(NMR) spectroscopy. Moreover, the surface tension and turbidity of the solutions of the products were measured for their potential application in the removal of dissolved and colloidal substances in paper cycling water.
文摘There are many natural sources to obtain pharmaceutical grade starch, one of which is banana (<i><i><span style="font-family:Verdana;">Musa</span></i><span style="font-family:Verdana;"> × </span><i><span style="font-family:Verdana;">paradisiaca L</span></i><span style="font-family:Verdana;">.</span></i>);nevertheless, the use of native starch has certain disadvantages compared to modified starches, whose disintegrating properties are better. In this study, starch extracted from rejected fruits of <i><i><span style="font-family:Verdana;">Musa</span></i><span style="font-family:Verdana;"> × </span><i><span style="font-family:Verdana;">paradisiaca L</span></i><span style="font-family:Verdana;">.</span></i>, was modified by acetylation, under the following optimized experimental conditions: 130 mL acetic anhydride, 3 mL sodium hydroxide 50% p/v for each 15 grams of native starch, at 123℃ during 3 hours. The reaction resulted in a modified green banana starch with twice as much swelling capacity compared to unmodified (native) starch;acetylation was verified by infrared spectroscopy and degree of substitution of acetyl groups by back titration. The dissolution profiles of Ibuprofen tablets <span style="font-family:Verdana;">made </span><span style="font-family:Verdana;">with</span><span> </span><span style="font-family:Verdana;">banana modified starch and commercial disintegrant, ha</span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> no differences according with their similarity factor</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""> <i><span style="font-family:Verdana;">f</span></i><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">. It is concluded that it is feasible to use green banana starch modified through acetylation as a pharmaceutical disintegrant.</span></span>
文摘Bio-degradable cassava starch-based adhesives were produced from chemically gelatinized starch formulations. The varying combinations of process parameters applied include: concentration of gelatinization modifier, mass % borax/starch, and temperature of reaction mixture. The physico-chemical parameters for characterizing the adhesive samples were viscosity, density, pH and bonding strength. The effects of the variation of process parameters on the quality of the adhesives were assessed using response surface (central composite) designs with 2 factors, to relate the highest adhesive quality with the optimal combination of process factors. The adhesives produced using HCl as the gelatinization modifier were of a higher quality than those produced using NaOH with one of the most important quality assessment parameters which is the bond strength being 22.31 kPa at 0.01 M and 20% mass borax/starch and 11.60 kPa at 0.01 M and 8% mass borax/starch for HCl and NaOH respectively. The experimental results demonstrated that the optimal temperature for the production of the adhesive was 85˚C.
文摘This paper deals with the preparation of cationic starch with high degree of substitute by dry-process. The corn starch and the alkali catalyst are mixed in the mixer, then added the cationic etherifying agent (3-chloro-2-hydroxypropyltrimethylammonium chloride). The reacting time is for 5 hours at the temperature of 70℃. The cationic starch with high degree of substitution is used as anionic charge neutralizing agents to improve filler retention in wet-end section of papermaking machine.