Polyvinyl acetal foam material, preparation method thereof and cervical dilation device
阅读说明：本技术 聚乙烯醇缩醛泡沫材料及其制备方法和***装置 (Polyvinyl acetal foam material, preparation method thereof and cervical dilation device ) 是由 万方 杨华蓉 李华 黄猛 张劲松 李博 于 2019-12-09 设计创作，主要内容包括：本发明公开了聚乙烯醇缩醛泡沫材料及其制备方法和宫颈扩张装置；制备方法包括：(1)制备聚乙烯醇缩醛多孔泡沫：原料混合,反应得到所述聚乙烯醇缩醛多孔泡沫；所述原料由聚乙烯醇、水、交联剂、成孔剂和酸性催化剂组成；(2)切割；(3)干燥；(4)压缩成型；所述聚乙烯醇缩醛泡沫材料宏观表面也很光滑、无缺陷,表层韧劲大,使用安全,具有良好的吸水,具有较大的拉伸强度,回弹性能佳,可作为宫颈扩张棒棒体用于宫颈扩张装置。(The invention discloses a polyvinyl acetal foam material, a preparation method thereof and a cervical dilatation device; the preparation method comprises the following steps: (1) preparation of polyvinyl acetal cellular foam: mixing the raw materials, and reacting to obtain the polyvinyl acetal porous foam; the raw materials consist of polyvinyl alcohol, water, a cross-linking agent, a pore-forming agent and an acid catalyst; (2) cutting; (3) drying; (4) compression molding; the polyvinyl acetal foam material has the advantages of smooth macroscopic surface, no defect, high surface toughness, safe use, good water absorption, high tensile strength and good resilience, and can be used as a cervical dilating rod body for a cervical dilating device.)
1. A method for preparing a polyvinyl acetal foam material, comprising:
(1) preparation of polyvinyl acetal cellular foam: mixing the raw materials, and reacting to obtain the polyvinyl acetal porous foam; the raw materials consist of polyvinyl alcohol, water, a cross-linking agent, a pore-forming agent and an acid catalyst; the pore-forming agent is potato starch and corn starch, and the weight ratio of the potato starch to the corn starch is 3.5-4.5: 1; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the water is 10-15 ml per 1g of polyvinyl alcohol, the dosage of the cross-linking agent is 1.0-1.5 ml per 1g of polyvinyl alcohol, the dosage of the pore-forming agent is 0.45-0.55 g per 1g of polyvinyl alcohol, and the dosage of the acidic catalyst is more than or equal to 1ml per 1g of polyvinyl alcohol;
(2) cutting;
(3) drying;
(4) and (4) compression molding.
2. The method according to claim 1, wherein the crosslinking agent is formaldehyde.
3. The method according to claim 1, wherein the reaction is a crosslinking reaction at a crosslinking temperature of 50 to 53 ℃.
4. The method according to claim 1, wherein the process for preparing the cellular foam of polyvinyl acetal comprises:
A. mixing polyvinyl alcohol and water, stirring, and heating at 80-110 ℃ until the polyvinyl alcohol is completely dissolved; the water consumption is 10-15 ml per 1g of polyvinyl alcohol;
B. controlling the temperature to be 53-78 ℃, adding the pore-forming agent, stirring, and reacting for 5-20 min; the pore-forming agent is potato starch and corn starch, and the weight ratio of the potato starch to the corn starch is 3.5-4.5: 1; the cross-linking agent is formaldehyde or paraformaldehyde; the amount of the pore-forming agent is 0.45-0.55 g per 1g of polyvinyl alcohol;
C. controlling the temperature to be 50-53 ℃, adding the cross-linking agent, stirring, and reacting for 5-20 min; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the cross-linking agent is 1.0-1.5 ml per 1g of polyvinyl alcohol;
D. controlling the temperature to be 50-53 ℃, adding the acidic catalyst, stirring, and reacting for 10-25 min; the dosage of the acidic catalyst is more than or equal to 1ml per 1g of polyvinyl alcohol;
E. preserving the heat for 6 to 12 hours at the temperature of between 50 and 53 ℃;
F. and (3) post-treating the polyvinyl acetal porous foam until the pH value is 6-7, and removing the residual formaldehyde.
5. The preparation method according to claim 1, wherein the step (2) specifically comprises: controlling the water content of the polyvinyl acetal porous foam to be 40-60 wt%, and freezing and cutting.
6. The preparation method according to claim 5, wherein the step (2) specifically comprises: centrifuging the polyvinyl acetal porous foam, adding water until the water content of the polyvinyl acetal porous foam is 40-60 wt%, and freezing and cutting.
7. The method for preparing according to claim 1, wherein the drying process is in particular forced air drying or pulsating vacuum sterilization drying.
8. The preparation method according to claim 1, wherein the compression molding process is specifically: and (4) compression molding by adopting a hydraulic press.
9. A polyvinyl acetal foam material produced by the production method according to any one of claims 1 to 8.
10. A cervical dilation apparatus, comprising: the cervical dilation rod body; the cervical dilating rod body is the polyvinyl acetal foam material prepared by the preparation method of any one of claims 1 to 8.
Technical Field
The invention relates to the technical field of medical instruments, in particular to a polyvinyl acetal foam material, a preparation method thereof and a cervical dilatation device.
Background
The center of the cervix is a long fusiform lumen with a slightly flattened front and back, which is mainly composed of connective tissue and also contains smooth muscle fibers, blood vessels and elastic fibers. When in gynecological operations such as ring removal, ring placement, induced abortion, uterine curettage and the like, a cervical dilator is usually required to dilate the cervical orifice during the operation because the cervical orifice is tight, so as to achieve the purpose of the operation. Clinically, the cervix uteri is dilated by a physical rigid dilation mode of a cervix uteri dilating rod with different diameters made of metal or rigid plastics, which often causes long operation time, great pain to patients and easily causes adverse reactions such as uterine injury, embryo injury, bleeding and the like.
At present, in order to realize the slow expansion of the cervix, relieve the pain of patients and reduce the operation difficulty and the occurrence of complications, a slow expansion type disposable cervix expansion rod with self-expansion performance is prepared by utilizing the water absorption expansion characteristic of a high polymer material. However, the expansion rod made of the self-expanding material adopted at present has the problem of low water absorption expansion rate, and is difficult to meet the clinical use requirement.
Disclosure of Invention
In view of the above, the present application provides the polyvinyl acetal foam material, the preparation method thereof and the cervical dilatation device of the present invention; the polyvinyl acetal foam material has smooth macroscopic surface, no defect, strong surface layer, safe use, good water absorption, larger tensile strength and good resilience, and can be used as a cervical dilating rod body for a cervical dilating device.
In order to solve the technical problems, the technical scheme provided by the application is a preparation method of a polyvinyl acetal foam material, which comprises the following steps:
(1) preparation of polyvinyl acetal cellular foam: mixing the raw materials, and reacting to obtain the polyvinyl acetal porous foam; the raw materials consist of polyvinyl alcohol, water, a cross-linking agent, a pore-forming agent and an acid catalyst; the pore-forming agent is potato starch and corn starch, and the weight ratio of the potato starch to the corn starch is 3.5-4.5: 1; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the water is 10-15 ml per 1g of polyvinyl alcohol, the dosage of the cross-linking agent is 1.0-1.5 ml per 1g of polyvinyl alcohol, the dosage of the pore-forming agent is 0.45-0.55 g per 1g of polyvinyl alcohol, and the dosage of the acidic catalyst is more than or equal to 1ml per 1g of polyvinyl alcohol;
(2) cutting;
(3) drying;
(4) and (4) compression molding.
Preferably, the polyvinyl alcohol is polyvinyl alcohol 1788.
Preferably, the crosslinking agent is formaldehyde.
Preferably, the crosslinking agent is 37 to 40 wt% formaldehyde.
Preferably, the acidic catalyst is selected from one or more of hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid and oxalic acid.
Preferably, the acidic catalyst is sulfuric acid.
Preferably, the acidic catalyst is 50 wt% sulfuric acid.
Preferably, the reaction is a crosslinking reaction with a crosslinking temperature of 50-53 ℃.
Preferably, the weight ratio of potato starch to corn starch is 4: 1.
Preferably, the amount of the water is 13ml per 1g of polyvinyl alcohol, the amount of the cross-linking agent is 1.2ml per 1g of polyvinyl alcohol, the amount of the pore-forming agent is 0.5g per 1g of polyvinyl alcohol, and the amount of the acid catalyst is 1ml per 1g of polyvinyl alcohol.
Preferably, the process for preparing the polyvinyl acetal porous foam specifically comprises the following steps:
A. mixing polyvinyl alcohol and water, stirring, and heating at 80-110 ℃ until the polyvinyl alcohol is completely dissolved; the water consumption is 10-15 ml per 1g of polyvinyl alcohol;
B. controlling the temperature to be 53-78 ℃, adding the pore-forming agent, stirring, and reacting for 5-20 min; the pore-forming agent is potato starch and corn starch, and the weight ratio of the potato starch to the corn starch is 3.5-4.5: 1; the cross-linking agent is formaldehyde or paraformaldehyde; the amount of the pore-forming agent is 0.45-0.55 g per 1g of polyvinyl alcohol;
C. controlling the temperature to be 50-53 ℃, adding the cross-linking agent, stirring, and reacting for 5-20 min; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the cross-linking agent is 1.0-1.5 ml per 1g of polyvinyl alcohol;
D. controlling the temperature to be 50-53 ℃, adding the acidic catalyst, stirring, and reacting for 10-25 min; the dosage of the acidic catalyst is more than or equal to 1ml per 1g of polyvinyl alcohol;
E. preserving the heat for 6 to 12 hours at the temperature of between 50 and 53 ℃;
F. and (3) post-treating the polyvinyl acetal porous foam until the pH value is 6-7, and removing the residual formaldehyde.
Preferably, the process for preparing the polyvinyl acetal porous foam specifically comprises the following steps:
A. mixing polyvinyl alcohol and water, stirring, and heating at 97 deg.C until polyvinyl alcohol is completely dissolved; the dosage of the formaldehyde is 1.0-1.5 ml per 1g of polyvinyl alcohol;
B. controlling the temperature to be 67 ℃, adding the pore-forming agent, stirring, and reacting for 5-20 min; the pore-forming agent is potato starch and corn starch, and the weight ratio of the potato starch to the corn starch is 3.5-4.5: 1; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the pore-forming agent is 1.0-1.5 ml per 1g of polyvinyl alcohol;
C. controlling the temperature to be 53 ℃, adding the cross-linking agent, stirring, and reacting for 5-20 min; the cross-linking agent is formaldehyde or paraformaldehyde; the dosage of the cross-linking agent is 1.0-1.5 ml per 1g of polyvinyl alcohol;
D. controlling the temperature to be 50 ℃, adding the acidic catalyst, stirring, and reacting for 10-25 min; the dosage of the acidic catalyst is 0.5-1.2 ml per 1g of polyvinyl alcohol;
E. preserving the heat at 50 ℃ for 6-12 hours;
F. and (3) post-treating the polyvinyl acetal porous foam until the pH value is 6-7, and removing the residual formaldehyde.
Preferably, the step F specifically includes: and (3) treating the polyvinyl acetal porous foam by using an alkaline solution until the pH value is 6-7, and removing the formaldehyde residue by using hydrogen peroxide.
Preferably, the alkaline solution is an aqueous sodium hydroxide solution.
Preferably, the step (2) specifically comprises: controlling the water content of the polyvinyl acetal porous foam to be 40-60 wt%, and performing freezing cutting
Preferably, the step (2) specifically comprises: centrifuging the polyvinyl acetal porous foam, adding water until the water content of the polyvinyl acetal porous foam is 40-60 wt%, and freezing and cutting;
preferably, the freezing and cutting process specifically comprises: freezing at 15 deg.C for >8h, and cutting.
Preferably, the drying process is air drying or pulse vacuum sterilization drying.
Preferably, the drying process is specifically pulse vacuum sterilization drying.
Preferably, the pulse vacuum sterilization drying specifically comprises: carrying out pulse vacuum sterilization at 40-50 ℃ and-75-60 kpa for 60-90 min.
Preferably, the forced air drying process specifically comprises: and (3) drying by blast air at 40-60 ℃ for 4-10 h.
Preferably, the forced air drying process specifically comprises: air-blast drying at 60 deg.C for 4 h.
Preferably, the compression molding process specifically comprises: and (4) compression molding by adopting a hydraulic press.
Preferably, the compression molding process specifically comprises: pressing into rod shape by hydraulic press.
The invention also provides a polyvinyl acetal foam material prepared by the preparation method.
Preferably, the polyvinyl acetal foam material has an acetalization degree of: the degree of acetalization of polyvinyl formal is: 55 to 70 percent.
Preferably, the pore size of the polyvinyl acetal foam material is 0.02-1.00 mm.
Preferably, the water absorption multiple of the polyvinyl acetal foam material is as follows: the weight m of the polyvinyl formal porous foam after completely absorbing water and the constant weight after dryingQuantity m1Calculating the water absorption times according to the weight ratio
The present invention also provides a cervical dilation apparatus comprising: the cervical dilation rod body; the cervical dilating rod body is the polyvinyl acetal foam material prepared by the preparation method.
Preferably, the cervical dilator is a cervical dilator or a cervical dilating rod.
Compared with the prior art, the detailed description of the application is as follows:
the preparation method of the polyvinyl acetal foam material comprises the following steps: (1) preparation of polyvinyl acetal cellular foam: mixing the raw materials, and reacting to obtain the polyvinyl acetal porous foam; (2) cutting; (3) drying; (4) and (4) compression molding. The raw materials consist of polyvinyl alcohol, water, a cross-linking agent, a pore-forming agent and an acid catalyst; the polyvinyl acetal foam material has smooth macroscopic surface, no defect, strong surface layer, safe use, good water absorption, higher tensile strength and good resilience, and can be used as a cervical dilating rod body for a cervical dilating device.
According to the invention, the potato starch and the corn starch are compounded to be used as pore-forming agents, and the screening and proportioning are carried out, so that the comprehensive effects of the potato starch and the corn starch are exerted, and the product is ensured to have small density, be spongy, good rebound resilience and good water absorption. In the process of polyvinyl formal, starch in the system expands under acidic conditions to occupy a certain space, and during forming, the starch is dissolved into paste again and hydrolyzed to form pores. The addition temperature of the starch is controlled to avoid, the starch is quickly gelatinized when the temperature is too high, and the obtained product has multiple pores, fine pores, softness and no elasticity; the temperature is not required to be too low, the pore-forming agent cannot expand, the hydrolysis speed is extremely slow, the dissolution is difficult, and the pore-forming rate is reduced.
The acidic catalyst is added to provide acidic conditions for the hydroformylation of polyvinyl alcohol, and plays a role of the catalyst. The dosage of the acid catalyst is controlled, and the condition of incomplete crosslinking under the condition of a small amount of the acid catalyst is avoided.
The dosage of the cross-linking agent is controlled, the formalization degree is increased, and the uniform pore-forming is ensured.
The invention controls the crosslinking temperature, and avoids the problems that the distribution of holes wrapped inside is not uniform, the formaldehyde is seriously volatilized, and the environment is polluted because the temperature is overhigh and the viscosity of the solution is rapidly increased. Avoid the problems of too low temperature and long acetalization time, which causes too long production flow and is not suitable for industrial production.
The invention adopts a method of water-containing freezing cutting after controlling the water content, so that the prepared polyvinyl acetal foam material is used for the cervical dilator, and has smooth surface, safe use and accurate size.
The invention adopts blast drying or pulse vacuum sterilization cabinet for drying, so that the prepared polyvinyl acetal foam material is used for the cervical dilator, and has smooth macroscopic surface, safe use and accurate size.
The invention adopts a hydraulic press for compression, so that the prepared polyvinyl acetal foam material is used for the cervical dilator, and has smooth macroscopic surface, safe use and accurate size and good resilience.
According to the analysis, the water content of the polyvinyl acetal porous foam is controlled to be 40-60 wt%, and a cutting product with smooth edge and small cutting error can be obtained by freezing and cutting, so that the prepared polyvinyl acetal foam material is used for the cervical dilator, and has the advantages of smooth surface, safety in use and accurate size.
The drying is carried out by adopting blast drying or a pulse vacuum sterilization cabinet, so that the deformation and the depression are avoided, the size shrinkage is reduced, and the pulse vacuum sterilization cabinet can realize sterilization; namely, the prepared polyvinyl acetal foam material is used for the cervical dilator by adopting blast drying or pulse vacuum sterilization cabinet for drying, and has smooth macroscopic surface, safe use and accurate size.
The prepared polyvinyl acetal foam material is used for the cervical dilator, and has smooth macroscopic surface, safe use and good size accuracy and resilience.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the following detailed description of the present invention is provided with reference to specific embodiments.