Silicone Rubber Heat Stabilizers
[Mechanism]
Silicone rubber in a confined high-temperature oxygen-free conditions mainly react in the main chain rearrangement thermal degradation, that is, the depolymerization reaction took place, so that the products softened (or soften), resulting in the loss of mechanical strength, loss of use value. The high temperature in the aerobic conditions, mainly polymer-based side of the oxidation, the formation of alkyl radicals, and free radical reactions result in coupling the seal of cross-linking density, so that the products gradually harden, and even the occurrence of cracks (known as the Sclerosis). In the silicone rubber by adding cerium oxide, prevents oxidation of side-chain polysiloxane cross-linked and the main chain of degradation. To a certain temperature range to prevent the silicone rubber as a result of free radical oxidation reactions generated, but also in the air under the O2 regeneration; absorbed through the silicone rubber to some of the catalytic reaction of the degradation of micro-acid or alkaline substances In order to play a silicone rubber on the role of heat-stable. At the same time, ceria special electronic structure (f Electron shell is not filled with) so that it easier to form complex, the formation of complex molecules through the rubber block segment of the campaign to curb the rubber in the solvent of swelling, resulting in improved rubber Of oil.
[Product properties]
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Control of cerium oxide surfactant, so that the cerium oxide has a good ability of oxygen and thus inhibit the oxidation of side chains.
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Control of the size and surface characteristics of cerium oxide , so that the cerium oxide and silicon rubber has a good affinity, in favor of cerium oxide full hybrid in the silicone rubber.
[Technology Parameters]
|
Model
|
RT-CE-1
|
|
Rare earth purity (wt%)
|
TREO
|
>99
|
|
CeO2/TREO
|
99.9
|
|
La2O3
|
<0.01
|
|
Pr6O11
|
<0.02
|
|
Nd2O3
|
<0.01
|
|
Non-rare earth impurity (wt%)
|
Fe2O3
|
<0.01
|
|
CaO
|
<0.1
|
|
L.O.I
|
<0.3
|
|
F
|
<0.1
|
|
H2O
|
<0.5
|
|
Physical Propeties
|
D50
|
0.5-0.7 um
|
|
D100
|
<6 um
|
