Several Theoretical Issues of PVC heat stabilizers

1 Overview
PVC heat stabilizers are of practical value resin can become

indispensable plastic additives, for decades, the study of the thermal

decomposition mechanism and PVC heat stabilizers of the action, have a

great development, but heat stabilizers some theoretical issues, such

as the commonly used metal soap heat stabilizers, why zinc, cadmium,

aluminum soap in PVC in class early color small, and barium, calcium,

strontium initial coloring on larger? Same as Sn, Sb initial heat

stabilizer why organic carboxylate thermal stabilizer coloring big? And

its corresponding thiol salts early color WSD PVC plasticizer  on the small? And so on very

rare reports, the authors try to use the theory of atomic structure

theoretical analysis on some issues, engaged in the production and

application of heat stabilizers colleagues or some benefit.
2, organotin more excellent heat stability of the same alkyl mercaptan

more excellent than the initial thermal stability than the tin

carboxylate organotin carboxylate. The reason is due to the structure

of the tin atoms linked sulfur and oxygen caused by different. Oxygen

and sulfur cycle in the same element as the sixth element, the

difference lies in their different electronic structure. Here I want to

emphasize is: since heat stabilizers stable reaction types, only the

elimination of PVC unstable reactive  WSD stearic acid chlorine atoms and anti-oxidation

reaction is fundamentally prevent the degradation of PVC on the cross

Union, others, such as the absorption of hydrogen chloride, carbon ions

and undermine the positive reaction of the double bond are more serious

in PVC has exploded later (already de-HCL, after the formation of a

number of double bonds) remedy, which can eliminate unstable heat

stabilizers have a chlorine atom good initial hue (no or less to form a

double bond).
PVC heat stabilizers eliminate unstable premise that two chlorine

atoms, one of the stabilizer and the metal ions have a strong

complexation unstable chlorine atom; the other is an organic anion of a

strong carbon (C? ?) initial significant complexing capacity, only two

were strong complexing ability of PVC was small. (Nearly colorless,

both strong and mercaptan, the tin mercaptide heat stabilizer for PVC,

PVC excellent in hue, hue holding time is longer).
3, the initial metal soap coloration  WSD Chlorinated paraffin and long-term thermal stability of

organotin
3.1 is the beginning of soap coloring
    I found an interesting phenomenon at work, the nature of Mg and Ca

soap soap is very similar (initial coloring serious, but a better long

-term thermal stability), and Al and Zn soap soap is very similar

(excellent initial hue and serious "zinc burn" phenomenon); Mg, Ca, Sr,

Ba are the second main group of the periodic elements are similar in

nature, well understood, but it is the third main element Al, and Zn,

Cd is the second sub-group elements, their chemical properties very

similar to what it? Of course, there are diagonal periodicity principle

can explain this phenomenon, but the similarities and differences

between the chemical properties of the elements, the fundamental reason

is the similarities and differences between their atomic structure, its

external representation is characteristic of the original rare earth

heat stabilizer is a unique " Coupling resistance. " Because of this

feature to make it appear to have in the processing of the lubricant

additives and processing characteristics, promote resin plasticizing;

show excellent impact resistance agent effectiveness in increasing the

PVC toughness, improve the mechanical properties of products in the

finished product; with When oxygen-fillers such as CaCO3 and other

effects, the performance of "Capacity" effect, without affecting the

mechanical properties of the conditions that can increase the amount of

CaCO3.