The performance differences between pure silicone coatings and modified silicone coatings are mainly reflected in molecular structure, physical properties, application scenarios and costs. The following is a specific comparative analysis:

1. Differences in molecular structure and synthesis method
‌Pure silicone coatings‌
‌Main chain structure‌: With ‌Si-O-Si bond‌ as the core skeleton, the bond energy is as high as 422 kJ/mol, the molecular chain is flexible, and it can still rotate freely at low temperatures‌.
‌Side chain groups‌: mainly methyl or phenyl, providing steric hindrance effect and reducing intermolecular forces‌.
‌Synthesis process‌: Directly formed by hydrolysis and polycondensation of chlorosilane, without other resins participating in the reaction‌.

‌Modified silicone coatings‌
‌Modification method‌:
‌Cold mixing type‌: Physically mixed with polyester, epoxy and other resins to reduce the curing temperature (such as alkyd modification can be cured at room temperature)‌. ‌Co-condensation type‌: Silane intermediates are chemically bonded with organic resins (such as acrylic acid, polyurethane) to form an interpenetrating network structure‌.
‌Hybrid type‌: Nanofillers (such as POSS, silica) are introduced to enhance mechanical properties‌.
‌Structural optimization‌: Remove unstable groups (such as -NCO) to improve low-temperature stability‌.

2. Key performance comparison
‌Performance index‌ Pure silicone coating Modified silicone coating
‌Heat resistance‌ Resistant to high temperatures of 250~800℃, but high temperature curing (>200℃)‌ Resistant to 200~300℃ (heat resistance slightly reduced after modification), can be cured at low temperature (-10℃)‌
‌Low temperature flexibility‌ Elongation >200% at -50℃, stable impact strength‌ Elongation still >200% at -80℃ (polyether modified)‌
‌Adhesion‌ Weak (steel/glass substrate requires pretreatment)‌ Significantly improved (cross-cut adhesion ≤2 levels)‌
‌Mechanical strength‌ Low, easy to crack‌ Tensile strength increased by 40% (nano filler reinforcement)‌
‌Chemical corrosion resistance‌ Alkali resistant (100℃/3%NaOH/100h), but not acid/oil resistant‌ Balanced acid and alkali resistance (salt spray test >500h)‌
‌Convenience of construction‌ High temperature baking is required, and the construction window is narrow‌ Support spraying, rolling, room temperature or low temperature curing ‌
‌Cost‌ High raw material cost (pure resin price ≥ 10 times of ordinary coating) ‌ Reduce 30%~50% (mixed resin dilution cost) ‌

3. Functional characteristics and application scenarios ‌Irreplaceable nature of pure silicone coatings ‌ ‌Extreme environment ‌: aerospace engine insulation (resistant to 700℃), nuclear facility radiation protection coating ‌. ‌Electrical insulation ‌: H-class insulation material (breakdown voltage 100kV/mm), used for high-voltage transformers ‌. ‌Expanded application of modified silicone coatings ‌ ‌Building waterproofing ‌: low temperature crack resistance (-40℃ freeze-thaw cycle>150 times), self-cleaning (contact angle>110°) ‌. ‌Electronic protection ‌: three-proof paint (moisture-proof/mildew-proof/salt spray-proof), support -40~150℃ temperature change ‌. ‌Industrial anti-corrosion ‌: chemical pipeline acid and alkali resistant coating, with stronger adhesion than epoxy resin ‌.