Is there a difference between good and bad 107 silicone sealant?
Is there a difference between good and bad 107 silicone sealant?
Is there a difference between good and bad 107 silicone sealant?
107 silicone sealant, the raw material for silicone sealant, is available in different grades.
107 silicone sealant, known as α,ω-dihydroxypolydimethylsiloxane, is the foundation of silicone sealants. Its quality critically impacts their performance. High-quality 107 silicone sealant is typically produced using traditional, standardized processes, using intermediates such as the hydrolysis product of dimethyldichlorosilane (DMC) as raw materials. This process involves catalytic polymerization, degradation, neutralization, and desulfurization. This type of 107 silicone sealant offers consistent quality, minimal batch-to-batch variability, and a regular molecular chain structure. The resulting silicone sealant exhibits excellent weather resistance, tensile strength, and elastic recovery.
Low-quality 107 silicone sealant may use dimethyldichlorosilane hydrolyzate as a direct replacement for DMC. This eliminates the need for cracking and distillation steps, resulting in lower costs and a relatively affordable price. However, the hydrolyzate is a mixture of linear bodies and DMC, making quality difficult to control. The resulting 107 adhesive has poor thermal stability, making the resulting silicone sealant prone to irreversible shrinkage, hardening, cracking, and debonding. Furthermore, the quality of 107 adhesive varies among different viscosities. Generally speaking, high-viscosity 107 adhesives have longer and more entangled molecular chains, forming a denser and more stable three-dimensional network after curing, resulting in higher strength and elongation, but potentially poorer extrudability.
Furthermore, high-quality 107 adhesives typically have well-controlled volatiles that meet relevant standards. Excessively high volatiles often indicate poor quality and may negatively impact the performance of the cured silicone sealant.