Silicone Sealant VS Other Sealants

Introduction
Sealant, as an "invisible guardian" in the industrial and construction fields, is undergoing profound changes in its technological evolution and market landscape. Among them, silicone sealant holds an important position due to its unique properties, while polyurethane, epoxy resin and other sealants are also irreplaceable in specific fields. This article comprehensively compares the differences and competitive situations between silicone sealant and other sealants from dimensions such as material properties, application fields, environmental protection regulations, and market trends.


I. Material Properties and Technical Comparison
Silicone sealant
Temperature resistance: It has a wide applicable temperature range (-60℃ to 250℃), excellent resistance to high and low temperatures, and does not release heat when curing at room temperature.


Weather resistance and durability: The main chain is of Si-O structure, which has strong resistance to ultraviolet rays and ozone aging, and its service life can reach over 25 years.


Limitations


It has poor adhesion to porous materials (such as concrete) and requires surface treatment.


After curing, it is not easy to apply coating, and the plasticizer may leach out, causing pollution.


The price is relatively high and its mechanical strength is lower than that of polyurethane adhesive.


2. Polyurethane sealant
Strength and elasticity: The bonding strength is more than twice that of silicone sealant, and the elongation exceeds three times, making it suitable for dynamic joints.


Low-temperature performance: It remains elastic in cold environments, but has poor high-temperature resistance (usually ≤100℃).


Environmental friendliness: The single-component product is non-toxic after curing and can be used in drinking water projects.


3. Epoxy resin sealant
Strength and hardness: It has strong adhesion to metals and porous substrates, but poor toughness and is prone to cracking under cold and hot shock.


Applicable scenarios: It is suitable for the packaging of electronic components at room temperature and in scenarios with low requirements for environmental mechanics.


4. New type of sealant
Modified silicone sealant (MS sealant)


With silane-terminated polyether as the main chain, it combines the weather resistance of silicone and the coating property of polyurethane.


There is no plasticizer leaching, avoiding substrate contamination, and it is especially suitable for prefabricated buildings.


Silane-terminated polyurethane sealant


It has no residual isocyanate, low VOC content, and combines weather resistance and environmental friendliness.


Ii. Application Fields and Market Landscape
The dominant field of silicone sealant
Building curtain walls: Due to their weather resistance, they are widely used for sealing the joints of glass and aluminum alloy.


Electronics and new Energy: Excellent insulation, used for sealing photovoltaic modules and protecting power batteries.


Medical and aviation: High-temperature resistant and non-toxic formula, meeting the requirements of medical devices and aviation components.


2. Differentiated markets for other sealants
Polyurethane sealant


Automobile welding sealing, concrete joints (balance of strength and elasticity).


Epoxy resin sealant


PCB board packaging (with strong insulation and adhesion), but insufficient low-temperature resistance.


MS glue


Concrete joints in prefabricated buildings (bonded with porous materials and can be painted).


3. Global market landscape
Regional distribution: The Asia-Pacific region accounts for over 50% of the global share (mainly China), while Europe and America focus on high-end products.


Competitive situation


Silicone sealant is dominated by international enterprises such as Dow and Wacker.


Polyurethane adhesives are represented by Henkel and Sika.


The market share of MS glue in Japan exceeds 35%, and its growth rate in China is significant.


Iii. Environmental Protection Regulations and Technological Innovation-driven Development
Environmental protection policies have been tightened
VOC limit: The EU Eco-Design Regulation (2024/1781) requires that products be low-carbon throughout their entire life cycle. China's GB/T 35609-2025 has added a "low-carbon attribute" indicator.


Hazardous substance control: PFAS (perfluorinated compounds) have been restricted by the European Union, promoting the development of solvent-free silicone adhesives and bio-based polyurethane adhesives.


2. Technological innovation direction
Self-healing materials: Microcapsule technology enables sealants to automatically repair when cracks appear, extending their lifespan (for example, the target for sealants in power batteries is 15 years).


Intelligent sealing materials: Integrated sensors monitor stress changes in real time, suitable for aerospace and energy storage systems.


Bio-based materials: Polylactic acid modified silica gel reduces carbon emissions by over 60% and has obtained dual certifications from REACH and FDA.


Iv. Industry Challenges and Future Trends
Core pain point
Monopoly in the high-end market: Foreign-funded enterprises hold a 70% share of silicone structural adhesives.


Cost pressure: The price of bio-based raw materials is 80% higher than that of petroleum-based ones.


Talent gap: Interdisciplinary technical talents account for less than 5%.


2. Future trends
Functional integration: Sealants shift from "gap filling" to an integrated "sealing - protection - intelligence" model (such as 4D printing adhesives).


Greening: By 2025, the market share of low-VOC products will reach 40%, and the application of recycled materials will expand.


Scene segmentation


In the new energy sector, the demand for high-temperature resistant silicone sealant is increasing by 25% annually.


Medical miniaturization: 0.1mm grade precision dispensing for vascular robots.


Conclusion
Silicone sealant has significant advantages in weather resistance and applicable temperature, while polyurethane, epoxy resin and MS sealant are irreplaceable in terms of strength, environmental friendliness and specific scenarios. In the future, as environmental protection regulations become stricter and application scenarios diversify, high performance, bio-based and intelligent features will become the focus of industry competition. Enterprises need to seek breakthroughs in material innovation and cross-disciplinary collaboration.


Industry Outlook: The competition in sealants has transcended performance parameters and entered an era of deep integration of "material genes + digital intelligence". By 2030, smart responsive sealants and space-grade materials (such as adhesives specifically designed for lunar bases) may redefine industry boundaries.