Solution to core material delamination: compatibility modification of brucite powder polymer interface
In the field of composite materials, the performance of the core material directly affects the quality and application range of the final product. However, in the actual production process, the problem of core material delamination often troubles technicians and production enterprises. Especially when using brucite powder as a filler, the interface compatibility between it and the polymer matrix is insufficient, which often leads to a decrease in material properties and even affects the structural stability of the finished product. In order to solve this problem, compatibility modification of the interface between brucite powder and polymer has become a key research direction in recent years.
1、 Analysis of the reasons for delamination of core materials
Core material delamination usually occurs in multi-layer structures or composite materials, especially in polymer systems filled with brucite powder. The main reason for this phenomenon is that the interface bonding force between brucite powder and polymer is weak, which cannot form effective stress transmission. Specifically:
Polarity difference: Magnesite powder is an inorganic mineral material with a strong polarity on its surface; However, most polymers such as polypropylene (PP), polyethylene (PE), etc. are non-polar or weakly polar materials, and there is a significant difference in surface energy between the two.
High interfacial tension: Due to the different surface properties, the interfacial tension is high when the two come into contact, making it difficult to achieve good wetting and bonding.
Stress concentration during processing: In the forming process, if the interface bonding is poor, stress concentration can easily occur during cooling or stress, leading to microcracks and gradual propagation, ultimately resulting in delamination of the core material.
These issues not only reduce the mechanical properties of the material, but may also affect key indicators such as flame retardancy and heat resistance, severely restricting the application of brucite powder in high-performance composite materials.
2、 The necessity of interface compatibility modification
In order to improve the dispersibility and bonding strength of brucite powder in polymer matrix, effective interface modification must be carried out. Good interface bonding can not only improve the overall performance of materials, but also fully utilize the flame retardant and reinforcing effects of brucite powder, extending the service life of materials.
In addition, with the increasing demand for environmental protection and the promotion of green manufacturing concepts, more and more companies are paying attention to the research and development of halogen-free flame retardant materials. As an environmentally friendly flame retardant, brucite powder has the advantages of low smoke and low toxicity, but its application is limited by compatibility issues with polymers. Therefore, conducting research on the modification of the interface between brucite powder and polymer not only has important theoretical value, but also has broad engineering application prospects.
3、 Common interface modification methods
At present, the following modification strategies are mainly adopted to address the compatibility issue between brucite powder and polymer interface:
1. Surface coating treatment
By coating a layer of organic coupling agent or other functional substance on the surface of brucite powder, the interface bonding between it and the polymer can be improved. Common coupling agents include silane, titanate, aluminate, etc. These compounds can contain both inorganic and organic groups in their molecular structure, playing a bridging role, effectively reducing interfacial tension, and improving the interaction between fillers and matrices.
2. Surface graft modification
This method involves introducing active groups on the surface of brucite powder that can undergo chemical reactions with polymers, allowing them to form covalent or hydrogen bonds with polymer segments during subsequent processing, thereby significantly enhancing interfacial adhesion. For example, introducing functional groups such as maleic anhydride (MAH) into the surface of brucite powder through free radical induced grafting reaction, and then combining it with materials such as polypropylene, can significantly improve the tensile strength and impact toughness of composite materials.
3. In situ polymerization technology
In situ polymerization is a relatively advanced modification method, which directly carries out polymerization reaction in the presence of brucite powder. This method allows polymer molecular chains to naturally wrap around filler particles during the growth process, thereby achieving tighter interfacial bonding. Although the process complexity is high, it has shown excellent performance in certain high-end application fields.
4. Composite modification strategy
A single modification method is often difficult to meet complex engineering requirements, so more and more researchers tend to adopt a combination of multiple modification methods. For example, surface activation treatment is first carried out, and then combined with coupling agent coating and in-situ polymerization technology to form a multi-level and multifunctional interface structure, in order to achieve the best modification effect.
4、 Modification effect evaluation and performance testing
To verify the modification effect, it is usually necessary to conduct a series of performance tests on the modified composite materials, including:
Mechanical performance testing: such as tensile strength, bending strength, impact strength, etc., used to evaluate the overall mechanical properties of materials;
Thermal performance analysis: Detecting the thermal stability and crystallization behavior of materials through methods such as thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC);
Microstructure observation: Use scanning electron microscopy (SEM) to observe the dispersion state and interface bonding of fillers in the matrix;
Rheological performance testing: evaluating the processing flowability and viscoelastic changes of modified materials;
Flame retardant performance test: Determine the limit oxygen index (LOI) and vertical combustion level to determine whether the modification has improved the flame retardant ability of the material.
Through the above testing methods, the effectiveness of different modification methods can be comprehensively evaluated, and reliable basis can be provided for subsequent industrial applications.
5、 Industrial Applications and Future Prospects
Currently, brucite powder has been widely used in various fields such as wires and cables, automotive interiors, and building materials. By effectively modifying the interface of brucite powder, not only can the problem of core material delamination be solved, but its application potential in high-end fields such as new energy and aerospace can also be further expanded.
In the future, with the development of nanotechnology and intelligent materials, the functional modification of brucite powder will become a new research hotspot. For example, developing new interface modifiers with self-healing, antibacterial, thermal conductivity and other functions, or combining brucite powder with other nano fillers, is expected to achieve a leap in the performance of composite materials.
In short, the key to solving the problem of core material delamination lies in improving the interfacial compatibility between brucite powder and polymer. Through scientific and rational modification methods, not only can material properties be optimized, but the entire composite materials industry can also be promoted to a higher level of development.