Sulfur-containing rigid humidity-responsive materials and their preparation methods
Sulfur-containing copolymers were prepared under mild conditions using anionic copolymerization, which solved the problems of weak bonding and complex preparation of multilayer structures, enabling the application of highly efficient humidity-responsive materials suitable for intelligent humidity actuators and underwater grasping applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGZHOU UNIV
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-02
AI Technical Summary
Existing humidity-responsive films with multilayer structures suffer from weak interlayer bonding, easy delamination after long-term use, complex manufacturing processes, and low efficiency of flexible materials in driving deformation, making it difficult to work stably in complex environments.
Sulfur-containing copolymers were prepared under mild conditions using anionic copolymerization. Rigid humidity-responsive materials were then formed by casting. Elemental sulfur, acrylamide monomers, and epoxy monomers were copolymerized under the action of an alkaline catalyst to form materials with high crosslinking density and hydrogen bond density.
The prepared material has high mechanical properties and good humidity response, making it suitable for mass production. The preparation process is simple, and the catalyst is free of heavy metal ions, making it suitable for fields such as intelligent humidity actuators and underwater grasping.
Smart Images
Figure CN122127537A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials, and specifically discloses a sulfur-containing rigid humidity-responsive material and its preparation method. Background Technology
[0002] Humidity-responsive films, as a type of smart material that can sense changes in ambient humidity and generate reversible deformation, optical property changes, or electrical signal outputs, show broad application prospects in fields such as soft robots, humidity sensors, smart packaging, wearable devices, and controlled drug release.
[0003] However, current strategies for constructing humidity-responsive thin films are mainly based on multilayer heterostructure designs. These multilayer structures typically combine hydrophilic and hydrophobic layers, utilizing asymmetric swelling under humidity gradients to drive the behavior. However, these structures often suffer from weak interlayer bonding, delamination during long-term cycling, and complex fabrication processes, limiting their durability and large-scale production in practical applications. Furthermore, most of the prepared materials are flexible, exhibiting low deformation efficiency and difficulty in operating stably in complex environments. Therefore, designing and synthesizing novel humidity-responsive materials with excellent performance remains a significant challenge. Summary of the Invention
[0004] To address the challenges of multilayer structures, hydrophilic and hydrophobic layers are often combined. However, such structures frequently suffer from weak interlayer bonding, delamination during long-term use, and complex fabrication processes. This invention provides a humidity-responsive material and its preparation method using anionic copolymerization under mild conditions.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0006] The preparation method of rigid humidity-responsive material is as follows: elemental sulfur, acrylamide monomer, and epoxy monomer are prepared into a sulfur-containing copolymer under mild conditions by alkaline catalyst in the presence of solvent. Then, the rigid humidity-responsive material is obtained by casting.
[0007] Furthermore, the copolymerization reaction environment is a dry environment protected by inert gas, the reaction temperature is 25℃, and the reaction time is 24 to 48 hours.
[0008] The mass fractions of the sulfur-containing copolymer monomers produced by this invention are 35-46 parts of elemental sulfur, 28-33 parts of acrylamide monomer, 25-31 parts of epoxy monomer, and 0.02-0.03 parts of alkaline catalyst.
[0009] The acrylamide monomer is N,N-methylenebisacrylamide (MBA), the epoxy monomer is glycidyl methacrylate (GMA), and the alkaline catalyst is potassium hydroxide (KOH).
[0010] The solvent is N,N-dimethylformamide or dimethyl sulfoxide (DMSO), and the amount of it fed is consistent with the mass of the monomer.
[0011] After film formation by casting, the drying temperature range is 80-100℃, and the drying time range is 24-48h.
[0012] The sulfur-containing rigid humidity-responsive material prepared by the above method can be applied to fields such as intelligent humidity actuators and underwater grasping.
[0013] Beneficial effects:
[0014] (1) The raw materials of this invention are inexpensive and industrially available, have good material properties, a wide range of applications, and are suitable for mass production.
[0015] (2) The polymerization conditions are mild, the catalyst used does not contain heavy metal ions and is easy to remove; the polymerization process is simple, and the polymer can be prepared in one step and directly cast to make sulfur-containing humidity-responsive materials.
[0016] (3) N,N-methylenebisacrylamide and glycidyl methacrylate provide the system with higher crosslinking density and higher hydrogen bond density. The prepared humidity-responsive material has high mechanical properties and good humidity response effect, and has good application prospects. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the humidity response.
[0018] Figure 2 The image shows the FTIR spectrum of the sulfur-containing humidity-responsive material prepared in Example 1.
[0019] Figure 3 The stress-strain curves of the sulfur-containing humidity-responsive materials prepared in Example 1 and Comparative Example 1 are shown.
[0020] Figure 4 The images show the FTIR spectra of the sulfur-containing humidity-responsive material prepared in Example 1 on both sides.
[0021] Figure 5 TGA curves of sulfur-containing humidity-responsive materials prepared in Examples 1, 2 and 3.
[0022] Figure 6 The water contact angle diagram of the sulfur-containing humidity-responsive material prepared in Example 1 every minute.
[0023] Figure 7 The XRD curve of the sulfur-containing humidity-responsive material prepared in Example 1.
[0024] Figure 8The sulfur-containing humidity-responsive material prepared in Example 1 is shown in the underwater grasping process diagram. Detailed Implementation
[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0026] Example 1
[0027] 0.64 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of N,N-dimethylformamide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 84%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0028] Figure 8 This demonstration showcases the process of a thin-film material gripping and lifting a target object in water. When submerged, the membrane bends and deforms within 5 seconds, thus grasping the underwater object. Thanks to its inherent mechanical strength, the membrane can easily lift objects weighing ten times its own weight to the surface.
[0029] Example 2
[0030] 0.768 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of N,N-dimethylformamide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 80%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0031] Example 3
[0032] 0.896 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 76%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0033] Example 4
[0034] 1.024 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 74%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at high temperature for 24 h.
[0035] Example 5
[0036] 0.64 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 1.1372 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 34%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0037] Example 6
[0038] 0.64 g of elemental sulfur powder, 1.2332 g of N,N-methylenebisacrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 61%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0039] Compare with Example 1
[0040] 0.64 g of elemental sulfur powder, 0.2843 g of acrylamide, 0.5686 g of glycidyl methacrylate, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 59%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0041] Compare with Example 2
[0042] 0.64 g of elemental sulfur powder, 0.6166 g of N,N-methylenebisacrylamide, 0.2963 g of glycidyl ether, 0.05 g of potassium hydroxide, and 3 ml of dimethyl sulfoxide were weighed into a 25 mL flask in an argon-filled glove box. The flask was sealed with a rubber stopper and placed in an oil bath at 25 °C with stirring for 24 h. After the reaction was completed, a prepolymer was obtained with a yield of 54%. The prepolymer mixture was cast onto a substrate (polytetrafluoroethylene sheet) and cured at 100 °C for 24 h.
[0043] Table 1 Tensile properties of each embodiment and comparative example
[0044] Tensile strength (MPa) Elongation at break (%) Response time (s) Example 1 63.36±1.28 10.81±2.05 5 Example 2 56.74±2.78 11.14±2.75 4.7 Example 3 47.12±2.89 13.65±1.65 4.1 Example 4 40.97±1.38 13.65±2.36 3.6 Example 5 20.11±2.11 14.52±1.64 3.1 Example 6 35.64±1.25 13.33±1.68 2.7 Compare with Example 1 17.28±3.28 5.19±1.75 / Compare with Example 2 14.25±2.17 6.47±1.42 /
[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A sulfur-containing rigid humidity-responsive material, characterized in that, The sulfur-containing rigid humidity-responsive material is composed of the following components by mass: 35-46 parts elemental sulfur, 28-33 parts acrylamide monomer, 25-31 parts epoxy monomer, and 0.02-0.03 parts alkali catalyst.
2. The sulfur-containing rigid humidity-responsive material according to claim 1, characterized in that, The epoxy monomer is glycidyl methacrylate (GMA).
3. The sulfur-containing rigid humidity-responsive material according to claim 1, characterized in that, The acrylamide monomer is N,N-methylenebisacrylamide (MBA).
4. The sulfur-containing rigid humidity-responsive material according to claim 1, characterized in that, The alkaline catalyst is potassium hydroxide (KOH).
5. A method for preparing a sulfur-containing rigid humidity-responsive material according to claim 1, characterized in that, The preparation method is as follows: elemental sulfur, acrylamide monomer, and epoxy monomer are copolymerized in a solvent in the presence of an alkaline catalyst under a dry environment protected by an inert gas to prepare a sulfur-containing copolymer. The copolymer is then directly cast into a film to obtain a sulfur-containing rigid humidity-responsive material.
6. The method for preparing the sulfur-containing rigid humidity-responsive material according to claim 5, characterized in that, The solvent is N,N-dimethylformamide or dimethyl sulfoxide, and its feed amount is consistent with the monomer mass.
7. The method for preparing the sulfur-containing rigid humidity-responsive material according to claim 5, characterized in that, The copolymerization reaction temperature is 25°C, and the copolymerization reaction time is 24–48 h.
8. The method for preparing the sulfur-containing rigid humidity-responsive material according to claim 5, characterized in that, After casting, the drying temperature is 80-100℃ and the drying time is 24-48h.
9. An application of the sulfur-containing rigid humidity-responsive material according to claim 1, characterized in that, The sulfur-containing rigid humidity-responsive material is used in intelligent humidity actuators and underwater grasping applications.