CN115282320A - Bacteria-resistant PU film medical dressing and processing technology thereof - Google Patents
Bacteria-resistant PU film medical dressing and processing technology thereof Download PDFInfo
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Abstract
The invention relates to the technical field of antibacterial dressings, in particular to a bacteria-resistant PU film medical dressing and a processing technology thereof, and the processing technology comprises the following processes: (1) preparation of modified polyurethane: reacting chitosan with quaternary ammonium citrate to obtain quaternary ammonium citrate chitosan; preparing modified polyurethane by using polyester polyol, diisocyanate, 2-dimethylolpropionic acid and citric acid chitosan quaternary ammonium salt as raw materials; (2) preparation of medical dressing: and mixing the modified polyurethane and lignin, standing and drying to obtain the medical dressing. According to the invention, citric anhydride and tetradecyl dimethyl tertiary amine are crosslinked by using epoxy chloropropane, the chitosan is subjected to hydrophilic and antibacterial enhancement by using the product, and the obtained modified chitosan is introduced into a lignin and polyurethane crosslinking system, so that the hydrophilicity of the prepared medical dressing is improved, and the mechanical property, antibacterial capability and water resistance of the medical dressing are effectively improved.
Description
Technical Field
The invention relates to the technical field of antibacterial dressings, in particular to a medical dressing of a bacterium-blocking PU film and a processing technology thereof.
Background
The skin is the largest organ of the human body and can be used as a strong barrier to avoid serious damage to the human body caused by external factors such as external pathogenicity, microorganisms, chemistry, machinery and the like. When skin is damaged, the traditional concept considers that dry and disinfected wound is needed for healing of wound surface to realize healing under scab, but growth factors for promoting wound healing only can move under the scab, and the new granulation tissue is easy to damage, so that the healing process is repeated. As a substitute of skin, the medical dressing can keep the wound moist and clean, realize the healing without crusted skin, and the moist exudate and the keratinocyte hyperplasia under the closed dressing can protect the newborn granulation tissue from being damaged, and the growth factor can fully exert the effect and promote the wound healing. However, wound infection is an important problem for hindering wound healing, a simple waterborne polyurethane film cannot meet the antibacterial requirement of the prepared medical dressing, chitosan in the biological material has good antibacterial activity on gram-negative bacteria and gram-positive bacteria to limit wound infection, and after the chitosan and polyurethane are blended and compounded, the mechanical property of the medical dressing is poor and the antibacterial effect is not as expected due to strong intermolecular hydrogen bonding of the chitosan. Therefore, the antibacterial PU film medical dressing and the processing technology thereof are provided.
Disclosure of Invention
The invention aims to provide a bacteria-resistant PU film medical dressing and a processing technology thereof, and aims to solve the problems in the background technology.
In order to solve the technical problems, the invention provides the following technical scheme: a processing technology of a bacteria-blocking PU film medical dressing comprises the following processes:
(1) Preparing modified polyurethane:
crosslinking citric anhydride and tetradecyl dimethyl tertiary amine by using epoxy chloropropane to obtain citric acid quaternary ammonium salt;
reacting chitosan with quaternary ammonium citrate to obtain quaternary ammonium citrate chitosan;
preparing modified polyurethane, namely citrated chitosan quaternary ammonium salt modified polyurethane, by using polyester polyol, diisocyanate, 2-dimethylolpropionic acid and citrated chitosan quaternary ammonium salt as raw materials;
(2) Preparation of the medical dressing:
and mixing the modified polyurethane with lignin, standing and drying to obtain the medical dressing.
Further, the (1) comprises the following processes:
s1, mixing citric anhydride and isopropanol, heating to 30-50 ℃, and stirring for dissolving; adding tetradecyl dimethyl tertiary amine, stirring, heating to 60-80 ℃, and performing reflux reaction for 30-60 min; slowly adding epoxy chloropropane, reacting for 6-9 h at constant temperature within 30min; cooling to room temperature, and adding anhydrous ether for extraction; removing the solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain the citric acid quaternary ammonium salt;
s2, adding isopropanol, mixing with chitosan and citric acid quaternary ammonium salt, and reacting at the temperature of 20-35 ℃ for 3-4 h; centrifugally purifying, dissolving by using deionized water, washing by using absolute ethyl alcohol, and drying at 52-58 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing polyester polyol, isophorone diisocyanate and dibutyltin dilaurate, heating to 75-80 ℃, and reacting for 1-2 h; adding 2, 2-dimethylolpropionic acid and citric chitosan quaternary ammonium salt, adding butanone to adjust the viscosity of the system, and reacting for 2-3 h; reducing the temperature of the system to 60-65 ℃, adding triethylamine, and carrying out neutralization reaction for 5-10 min; adding ethylenediamine, adding deionized water at 0-5 ℃ for emulsification, and stirring at high speed for 30-40 min; and carrying out reduced pressure distillation to obtain the modified polyurethane-waterborne polyurethane emulsion.
Furthermore, the proportion of the citric anhydride and the isopropanol in the S1 is (10-15) 100mL;
the molar ratio of the citric anhydride to the tetradecyldimethyl tertiary amine to the epichlorohydrin is 1;
the citric anhydride is prepared by the following process: mixing 19.2g of anhydrous citric acid, 12.0g of acetic acid and 18.4g of acetic anhydride, heating to 35 ℃, and carrying out reflux reaction for 18 hours; the acetic acid was removed by distillation under reduced pressure, washed with chloroform and dried to constant weight in vacuo.
Citric acid: AR, from chemical agents, inc., of the national drug group;
in the technical scheme, isopropanol is used as a solvent, citric anhydride is dissolved, tetradecyl dimethyl tertiary amine is added to be mixed with the citric anhydride for reaction, and tertiary amine in the tetradecyl dimethyl tertiary amine attacks the anhydride, so that alkoxy ions and carbon anions are generated through ring opening. Then adding epoxy chloropropane to react the chloro group with tetradecyl dimethyl tertiary amine to generate quaternary ammonium salt; the epoxy group is subjected to the action of tertiary amine/quaternary ammonium salt, and is subjected to ring opening and alkoxy ion grafting in acid anhydride; structurally, one carboxyl group in citric acid is crosslinked with tetradecyldimethyl tertiary amine to obtain the quaternary ammonium citrate. In the reaction process, isopropanol contains proton-donating groups and can promote the ring-opening reaction of epoxy groups; the outer layer of the nitrogen atom of the tertiary amine contains unshared electron pairs and has nucleophilic property, and strong electronegativity of the tertiary amine can attack the carbon atom in an epoxy group to form negative oxygen ions so as to open the ring and promote the reaction of epoxy and acid anhydride; the generated quaternary ammonium salt catalyzes the epoxy reaction in the form of ammonium salt at the reaction temperature, so that the reaction between epoxy and anhydride is relatively slow and gentle. Carboxyl carbon in the acid anhydride is influenced by carbonyl oxygen and carboxyl, has stronger positive charge tendency, and is more easily attacked by nucleophilic reagents (tertiary amine and quaternary ammonium salt), so that epoxy groups in the epoxy chloropropane preferentially react with acid anhydride groups in the citric acid anhydride; and the citric acid quaternary ammonium salt with carboxyl and quaternary ammonium salt groups is obtained by controlling the molar weight of citric acid, tetradecyl dimethyl tertiary amine and epichlorohydrin.
Further, the molar ratio of the chitosan to the quaternary ammonium citrate in the S2 is 1 (1.0-1.5);
and (3) chitosan: is from Zhejiang gold shell biochemistry Co., ltd, and the deacetylation degree is 95.62%;
epoxy chloropropane: AR, from hippura biotechnology ltd;
tetradecyldimethylamine: AR, zhengzhou Jexon chemical products, inc.;
in the technical scheme, carboxyl in the quaternary ammonium citrate reacts with amino in chitosan for substitution, and the quaternary ammonium citrate is grafted with chitosan to obtain the quaternary ammonium citrate chitosan, which has more excellent water solubility and antibacterial capacity; and the chitosan and the quaternary ammonium salt group are matched, so that the surface tension, wetting and emulsifying properties of the citric acid chitosan quaternary ammonium salt can be enhanced, the antibacterial and hydrophilic capabilities of the prepared medical dressing are improved, and the subsequent preparation of the modified polyurethane emulsion in crosslinking with the xylonic acid is facilitated.
Further, the modified polyurethane in S3 is prepared from the following components in parts by weight: 8 to 15 portions of polyester polyol, 10.3 to 12.2 portions of isophorone diisocyanate, 0.010 to 0.015 portion of dibutyltin dilaurate, 1.2 to 1.6 portions of 2, 2-dimethylolpropionic acid, 1.8 to 2.0 portions of citric chitosan quaternary ammonium salt, 16 to 18 portions of butanone, 0.8 to 1.2 portions of triethylamine, 4.0 to 4.5 portions of ethylenediamine and 45 to 52 portions of deionized water;
polyester polyol: p-2719TL from Dongguan pure building high molecular materials, inc.;
in the technical scheme, polyester polyol and isophorone diisocyanate are used for synthesizing a polyurethane prepolymer, the polyurethane prepolymer is reacted with a hydrophilic chain extender 2, 2-dimethylolpropionic acid and citric acid chitosan quaternary ammonium salt, hydroxyl in the hydrophilic chain extender is reacted with an isocyanate group in isophorone diisocyanate to obtain waterborne polyurethane, triethylamine is used for neutralization reaction, ethylenediamine is used for amino chain extension, and deionized water is used for phase conversion to obtain a modified polyurethane emulsion, so that the modified polyurethane emulsion has more excellent hydrophilicity and antibacterial performance, and the water resistance and mechanical performance of the modified polyurethane emulsion are improved.
Further, the (2) comprises the following processes:
mixing the modified polyurethane with lignin, adding a sodium trimetaphosphate aqueous solution, and stirring for 60-90 min; standing for 48h at room temperature, and vacuum drying for 24h at the temperature of 45-52 ℃ to obtain the medical dressing.
Further, the medical dressing is prepared from the following components in parts by weight: 100 parts of modified polyurethane, 3.0-3.6 parts of lignin and 0.09-0.11 part of sodium trimetaphosphate;
the concentration of the sodium trimetaphosphate aqueous solution is (32-35) g/L;
the lignin is hydroxymethylated lignin, and the method specifically comprises the following processes: mixing 24g of lignin and 6.8g of formaldehyde, adding 15wt% of sodium hydroxide solution to adjust the pH value of the system to 11.5, and stirring and reacting for 5 hours at the temperature of 80 ℃; and (3) adjusting the pH value of the system to 2 by using 25wt% of dilute hydrochloric acid, performing suction filtration, washing the precipitate with water, and drying at 50 ℃ to constant weight.
Lignin: alkali lignin, available from Shenyang general and chemical industries, inc.;
in the technical scheme, the modified polyurethane emulsion is mixed with the lignin after hydrophilic modification, and the reaction of a sodium phosphate group in sodium trimetaphosphate and a hydroxyl group is utilized, carbamate in polyurethane can form a hydrogen bond with a phenolic hydroxyl group and an alcoholic hydroxyl group in the lignin, and the modified polyurethane is crosslinked with the lignin, so that the hydrophilicity of the prepared medical dressing can be improved, and the mechanical property, the antibacterial capability and the water resistance of the dressing are effectively improved.
Compared with the prior art, the invention has the following beneficial effects:
according to the bacteria-resistant PU film medical dressing and the processing technology thereof, citric anhydride and tetradecyl dimethyl tertiary amine are crosslinked by using epoxy chloropropane, the chitosan is subjected to hydrophilic and bacteria-resistant enhancement by using a product, and the obtained modified chitosan is introduced into a lignin and polyurethane crosslinking system, so that the hydrophilicity of the prepared medical dressing is improved, and the mechanical property, the antibacterial capability and the water resistance of the medical dressing are effectively improved.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The citric anhydride is prepared by the following process: mixing 19.2g of anhydrous citric acid, 12.0g of acetic acid and 18.4g of acetic anhydride, heating to 35 ℃, and carrying out reflux reaction for 18 hours; the acetic acid was removed by distillation under reduced pressure, washed with chloroform and dried under vacuum to constant weight.
The lignin is hydroxymethylated lignin, and the method specifically comprises the following steps: mixing 24g of lignin and 6.8g of formaldehyde, adding 15wt% of sodium hydroxide solution to adjust the pH value of the system to 11.5, and stirring and reacting for 5 hours at the temperature of 80 ℃; and (3) adjusting the pH of the system to 2 by using 25wt% of dilute hydrochloric acid, performing suction filtration, washing the precipitate with water, and drying at 50 ℃ to constant weight.
Citric acid: AR, from chemical agents, inc., of the national drug group;
and (3) chitosan: from Zhejiang gold shell biochemistry Co., ltd., the deacetylation degree is 95.62%;
epoxy chloropropane: AR, from hippura biotechnology ltd;
tetradecyldimethylamine: AR, zhengzhou Jexon chemical products, inc.;
polyester polyol: p-2719TL from Dongguan build high polymer materials, inc.;
lignin: alkali lignin, from Shenyang Prov and chemical Co.
Example 1
(1) Preparing modified polyurethane:
s1, mixing 10g of citric anhydride and 100mL of isopropanol, heating to 30 ℃, and stirring for dissolving; adding 13.9g of tetradecyl dimethyl tertiary amine, stirring, heating to 60 ℃, and carrying out reflux reaction for 30min; slowly adding 5.3g of epoxy chloropropane, finishing the addition within 30min, and reacting for 6h at constant temperature; cooling to room temperature, and adding anhydrous ether for extraction; removing the solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain the citric acid quaternary ammonium salt;
s2, taking 100mL of isopropanol, adding 10g of chitosan and 1.4g of quaternary ammonium citrate, mixing, and reacting at the temperature of 20 ℃ for 3 hours; centrifugally purifying, dissolving by deionized water, washing by absolute ethyl alcohol, and drying at 52 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ for reaction for 1h; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of citric chitosan quaternary ammonium salt, adding 16g of butanone to adjust the viscosity of the system, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.0g of lignin, adding 0.28g of 32g/L sodium trimetaphosphate aqueous solution, and stirring for 60min; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Example 2
(1) Preparing modified polyurethane:
s1, mixing 12g of citric anhydride and 100mL of isopropanol, heating to 40 ℃, and stirring for dissolving; adding 17.4g of tetradecyl dimethyl tertiary amine, stirring, heating to 70 ℃, and carrying out reflux reaction for 45min; slowly adding 6.6g of epoxy chloropropane, finishing the addition within 30min, and reacting for 8h at constant temperature; cooling to room temperature, and adding anhydrous ether for extraction; removing the solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain the citric acid quaternary ammonium salt;
s2, taking 100mL of isopropanol, adding 10g of chitosan and 1.72g of quaternary ammonium citrate, mixing, and reacting at the temperature of 27 ℃ for 3.5h; centrifugally purifying, dissolving by using deionized water, washing by using absolute ethyl alcohol, and drying at 55 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing 12g of polyester polyol, 11.2g of isophorone diisocyanate and 0.012g of dibutyltin dilaurate, and heating to 78 ℃ to react for 1.5h; adding 1.4g of 2, 2-dimethylolpropionic acid and 1.9g of citric chitosan quaternary ammonium salt, adding 17g of butanone to adjust the viscosity of the system, and reacting for 2.5 hours; reducing the temperature of the system to 62 ℃, adding 1.0g of triethylamine, and carrying out neutralization reaction for 8min; adding 4.2g of ethylenediamine, adding 48g of deionized water at the temperature of 2 ℃ for emulsification, and stirring at a high speed for 35min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.2g of lignin, adding 0.30g of 33g/L sodium trimetaphosphate aqueous solution, and stirring for 75min; standing at room temperature for 48h, and vacuum drying at 50 deg.C for 24h to obtain the medical dressing.
Example 3
(1) Preparing modified polyurethane:
s1, mixing 15g of citric anhydride and 100mL of isopropanol, heating to 50 ℃, and stirring for dissolving; adding 20.8g of tetradecyl dimethyl tertiary amine, stirring, heating to 80 ℃, and carrying out reflux reaction for 60min; slowly adding 7.9g of epoxy chloropropane, finishing the addition within 30min, and reacting for 9h at constant temperature; cooling to room temperature, and adding anhydrous ether for extraction; removing the solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain the citric acid quaternary ammonium salt;
s2, taking 100mL of isopropanol, adding 10g of chitosan and 2.1g of quaternary ammonium citrate, mixing, and reacting at 35 ℃ for 4h; centrifugally purifying, dissolving by deionized water, washing by absolute ethyl alcohol, and drying at 58 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing 15g of polyester polyol, 12.2g of isophorone diisocyanate and 0.015g of dibutyltin dilaurate, and heating to 80 ℃ to react for 2 hours; adding 1.6g of 2, 2-dimethylolpropionic acid and 2.0g of citric chitosan quaternary ammonium salt, adding 18g of butanone to adjust the viscosity of the system, and reacting for 3 hours; reducing the temperature of the system to 65 ℃, adding 1.2g of triethylamine, and carrying out neutralization reaction for 10min; adding 4.5g of ethylenediamine, adding 52g of deionized water at 0 ℃ for emulsification, and stirring at a high speed for 40min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.6g of lignin, adding 0.31g of 35g/L sodium trimetaphosphate aqueous solution, and stirring for 90min; standing at room temperature for 48h, and vacuum drying at 52 deg.C for 24h to obtain medical dressing.
Comparative example 1
(1) Preparing modified polyurethane:
s1, mixing 10g of citric acid and 100mL of isopropanol, heating to 30 ℃, and stirring for dissolving; adding 13.9g of tetradecyl dimethyl tertiary amine, stirring, heating to 60 ℃, and carrying out reflux reaction for 30min; slowly adding 5.3g of epoxy chloropropane, finishing the addition within 30min, and reacting for 6h at constant temperature; cooling to room temperature, and adding anhydrous ether for extraction; removing solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain citric acid quaternary ammonium salt;
s2, taking 100mL of isopropanol, adding 10g of chitosan and 7.2g of quaternary ammonium citrate, mixing, and reacting at the temperature of 20 ℃ for 3 hours; centrifugally purifying, dissolving by using deionized water, washing by using absolute ethyl alcohol, and drying at 52 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ for reaction for 1h; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of citric chitosan quaternary ammonium salt, adding 16g of butanone to adjust the system viscosity, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.0g of lignin, adding 0.28g of 32g/L sodium trimetaphosphate aqueous solution, and stirring for 60min; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Comparative example 2
(1) Preparing modified polyurethane:
s1, taking 100mL of isopropanol, adding 10g of chitosan and 0.6g of citric acid, mixing, and reacting at the temperature of 20 ℃ for 3 hours; centrifugally purifying, dissolving by using deionized water, washing by using absolute ethyl alcohol, and drying at 52 ℃ to constant weight to obtain citric acid chitosan quaternary ammonium salt;
s3, mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ for reaction for 1h; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of citric chitosan quaternary ammonium salt, adding 16g of butanone to adjust the viscosity of the system, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.0g of lignin, adding 0.28g of 32g/L sodium trimetaphosphate aqueous solution, and stirring for 60min; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Comparative example 3
(1) Preparing modified polyurethane:
s1, mixing 10g of citric anhydride and 100mL of isopropanol, heating to 30 ℃, and stirring for dissolving; adding 13.9g of tetradecyl dimethyl tertiary amine, stirring, heating to 60 ℃, and carrying out reflux reaction for 30min; slowly adding 5.3g of epoxy chloropropane, finishing the addition within 30min, and reacting for 6h at constant temperature; cooling to room temperature, and adding anhydrous ether for extraction; removing solvent diethyl ether by infrared irradiation, and drying in vacuum to constant weight to obtain citric acid quaternary ammonium salt;
s2, mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ to react for 1 hour; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of quaternary ammonium citrate, adding 16g of butanone to adjust the viscosity of the system, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.0g of lignin, adding 0.28g of 32g/L sodium trimetaphosphate aqueous solution, and stirring for 60min; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Comparative example 4
(1) Preparing modified polyurethane:
mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ for reaction for 1h; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of chitosan, adding 16g of butanone to adjust the viscosity of the system, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane;
(2) Preparation of the medical dressing:
mixing 100g of modified polyurethane and 3.0g of lignin, adding 0.28g of 32g/L sodium trimetaphosphate aqueous solution, and stirring for 60min; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Comparative example 5
Mixing 8g of polyester polyol, 10.3g of isophorone diisocyanate and 0.010g of dibutyltin dilaurate, and heating to 75 ℃ to react for 1 hour; adding 1.2g of 2, 2-dimethylolpropionic acid and 1.8g of chitosan, adding 16g of butanone to adjust the viscosity of the system, and reacting for 2 hours; reducing the temperature of the system to 60 ℃, adding 0.8g of triethylamine, and carrying out neutralization reaction for 5min; adding 4.0g of ethylenediamine, adding 45g of deionized water at 5 ℃ for emulsification, and stirring at a high speed for 30min; carrying out reduced pressure distillation to obtain modified polyurethane; standing at room temperature for 48h, and vacuum drying at 45 deg.C for 24h to obtain medical dressing.
Experiment of the invention
The medical dressings obtained in examples 1 to 3 and comparative examples 1 to 5 were used to prepare samples, and the properties thereof were measured and the measurement results were recorded:
mechanical properties: preparing the prepared medical dressing into a dumbbell-shaped sample, and testing the tensile property of the sample in a dry and wet state by adopting a universal tensile machine at 25 ℃, wherein the tensile speed is 20mm/min; the wet state is that the sample is immersed in distilled water for 5 hours;
water absorption performance: preparing the prepared medical dressing into a sample of 2cm multiplied by 2cm, and immersing the sample in distilled water at room temperature for 24 hours; taking out, sucking water, weighing, repeating the operation until the weight of the sample is constant, and calculating the mass change rate before and after the sample absorbs water, and recording the mass change rate as the water absorption rate (%); and the swelling ratio = (m) was calculated Water (I) /ρ Water (W) +m Dry matter /ρ Dry matter ）/（m Dry food /ρ Dry food ) X 100%, wherein m Water (W) 、m Dry matter The masses of water and dry sample, in that order, p Water (I) 、ρ Dry food Density of water and dry sample in sequence;
antibacterial property: adding a dry sample into a liquid culture medium by adopting an oscillation method, swelling until the swelling is balanced, transferring the dry sample into a 75mL fresh beef peptone liquid culture medium, inoculating a bacterial liquid, and placing the mixture at the constant temperature of 37 ℃ for culturing for 24 hours; detecting the absorbances of an experimental group and a blank group (bacterial liquid without a sample) by using an ultraviolet spectrophotometer, and calculating the bacteriostasis rate = (the absorbance of the sample-the absorbance of the blank group)/the absorbance of the blank group multiplied by 100%;
from the data in the table above, it is clear that the following conclusions can be drawn:
the medical dressings obtained in examples 1 to 3 were compared with the medical dressings obtained in comparative examples 1 to 5, and the results of the examination were found to be,
compared with a comparative example, the tensile strength data of the medical dressing obtained in the examples 1-3 in a dry and wet state and the antibacterial rate data of the medical dressing to escherichia coli and staphylococcus aureus are higher than those of the medical dressing in the comparative example, and the tensile property, the water resistance and the antibacterial capacity of the medical dressing are improved; the data show that the medical dressing in the application still maintains better water absorption and swelling rate; the invention fully shows that the mechanical property, the antibacterial ability and the water resistance of the prepared medical dressing are improved;
compared with example 1, in comparative example 1, the component citric anhydride is replaced by citric acid with equal mass; in comparative example 2, the component quaternary ammonium citrate salt was replaced with an equimolar amount of citric acid; in the comparative example 3, the component of the citric acid chitosan quaternary ammonium salt is replaced by citric acid quaternary ammonium salt with equal mass; in the comparative example 4, the component of the citric acid chitosan quaternary ammonium salt is replaced by chitosan with equal mass; comparative example 5 on the basis of comparative example 4, the components lignin and sodium trimetaphosphate were deleted; the tensile strength data of the sample in a dry and wet state and the bacteriostatic rate data of the sample to escherichia coli and staphylococcus aureus are reduced, and the change rate of the swelling volume is increased, so that the medical dressing component and the process thereof can be set to improve the mechanical property, antibacterial capability and water resistance.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process method article or apparatus.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent change and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A processing technology of a bacteria-resistant PU film medical dressing is characterized in that: the method comprises the following processes:
(1) Preparing modified polyurethane:
mixing citric anhydride and isopropanol, heating to 30-50 ℃, and stirring for dissolving; adding tetradecyl dimethyl tertiary amine, stirring, heating to 60-80 ℃, and performing reflux reaction for 30-60 min; slowly adding epoxy chloropropane, reacting for 6-9 h at constant temperature within 30min to obtain quaternary ammonium citrate;
adding the isopropanol into the chitosan and the quaternary ammonium citrate salt, mixing, and reacting at the temperature of 20-35 ℃ for 3-4 h to obtain the quaternary ammonium citrate chitosan salt;
mixing polyester polyol, isophorone diisocyanate and dibutyltin dilaurate, heating to 75-80 ℃, and reacting for 1-2 h; adding 2, 2-dimethylolpropionic acid and citric chitosan quaternary ammonium salt, adding butanone to adjust the viscosity of the system, and reacting for 2-3 h; reducing the temperature of the system to 60-65 ℃, adding triethylamine, and carrying out neutralization reaction for 5-10 min; adding ethylenediamine, adding deionized water at 0-5 ℃ for emulsification, and stirring at a high speed for 30-40 min to obtain modified polyurethane;
(2) Preparation of the medical dressing:
and mixing the modified polyurethane with lignin, standing and drying to obtain the medical dressing.
2. The processing technology of the bacteria-blocking PU film medical dressing according to claim 1, characterized in that: the molar ratio of the chitosan to the citric acid quaternary ammonium salt is 1 (1.0-1.5).
3. The processing technology of the bacteria-blocking PU film medical dressing as claimed in claim 1, wherein: the modified polyurethane is prepared from the following components in parts by weight: 8 to 15 portions of polyester polyol, 10.3 to 12.2 portions of isophorone diisocyanate, 1.2 to 1.6 portions of 2, 2-dimethylolpropionic acid and 1.8 to 2.0 portions of citric acid chitosan quaternary ammonium salt.
4. The processing technology of the bacteria-blocking PU film medical dressing as claimed in claim 1, wherein: the molar ratio of the citric anhydride to the tetradecyldimethyl tertiary amine to the epichlorohydrin is 1.
5. The processing technology of the bacteria-blocking PU film medical dressing according to claim 1, characterized in that: the (2) comprises the following processes:
mixing the modified polyurethane with lignin, adding a sodium trimetaphosphate aqueous solution, and stirring for 60-90 min; and standing and drying to obtain the medical dressing.
6. The processing technology of the bacteria-resistant PU film medical dressing according to claim 5, wherein: the medical dressing is prepared from the following components in parts by weight: 100 parts of modified polyurethane, 3.0-3.6 parts of lignin and 0.09-0.11 part of sodium trimetaphosphate.
7. The processing technology of the bacteria-resistant PU film medical dressing according to claim 5, wherein: the concentration of the sodium trimetaphosphate aqueous solution is (32-35) g/L.
8. A bacteria-resistant PU film medical dressing prepared by the processing technology of any one of claims 1-7.
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| CN111620988A (en) * | 2020-06-15 | 2020-09-04 | 张玉花 | Long-acting antibacterial dressing and preparation method thereof |
| CN114246973A (en) * | 2020-09-25 | 2022-03-29 | 南京大可实业有限公司 | Medical dressing material and preparation method thereof |
| CN114380979A (en) * | 2021-10-21 | 2022-04-22 | 上海奔佑新材料科技有限公司 | Polyurethane prepolymer for medical dressing and preparation method thereof |
| CN114177341A (en) * | 2021-12-17 | 2022-03-15 | 常州美杰医疗用品有限公司 | Preparation method of antibacterial medical foam dressing |
| CN114470298A (en) * | 2021-12-21 | 2022-05-13 | 中国科学院宁波材料技术与工程研究所 | Antibacterial nano silver/lignin polyurethane dressing and one-step preparation method thereof |
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| CN116199848A (en) * | 2022-12-19 | 2023-06-02 | 南通新艺材料科技有限公司 | Antibacterial polyurethane foam material containing anions and preparation method thereof |
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