Because of its advantages and advantages of silicone sealant and polyurethane sealant, it has shown excellent weather resistance, durability, high deformation resistance, good adhesion, painting, environmental friendliness, low stain, low viscosity and excellent workability. It has been paid more and more attention by the domestic construction industry, while in the industrial fields such as automobile manufacturing, rail transit, and integrated transportation Packing manufacturing, equipment manufacturing, electronic and electrical fields are also getting more and more promotion and application.


Synthesis of silane modified polyether


The structural characteristics of silane modified polyether are that the main chain is macromolecular polyether and the end group is silane group containing hydrolyzable group. The synthesis of silane modified polyether is usually completed by two steps.


The first step: allyl terminated polyether intermediates were prepared by chain extension reaction with allyl polyether alcohol and hydroxyl terminated polyether as raw materials, dihalomethane (h2cx2) as chain extender and caustic as catalyst.

Synthesis step 1 of silane modified polyether

The second step: in the presence of platinum catalyst, silane modified polyether was prepared by the reaction of refined intermediate and methyldimethoxysilane.
Synthesis step 2 of silane modified polyether

Curing mechanism of silane modified polyether sealant

The curing mechanism of MS sealant belongs to wet curing. In the presence of room temperature, humidity and appropriate catalysts (amines, tin, etc.), the alkoxy in the alkoxy end group is hydrolyzed to silanol group (Si oh); then the Si OH group or Si oh and Si 0ch are condensed to release water or methanol to form si-0-si bond; finally, the si-0-si bond is used as the network crosslinking point, and the soft crosslinking point is used between the crosslinking points The shape structure elastomer of polyether chain.

Advantages of silane modified polyether sealant

Some properties of silicone sealant, polyurethane sealant and silane modified polyether sealant are compared

The good comprehensive properties of silane modified polyether adhesive are closely related to the special structure of its basic polymer (silyl terminated polyether).

Characteristics of polyether sealant modified by silane

1. The universality of bonding to the base material. Due to the low surface energy and high permeability of the basic polymer (silyl terminated polyether), it has good wetting ability for most inorganic, metal and plastic substrates, so it can produce good adhesion to the substrate.