PVC heat stabilizers aggregation structure

Performance of PVC heat stabilizers, it must be possible for PVC structure and evolution of condensed matter research, the following come to you to do an analysis.
First, PVC aggregation structure
PVC by suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization synthesis, and tribasic lead sulfate  suspension polymerization production accounted for 85% of total production, except for some special purpose materials, the vast majority of suspension PVC products.
The condensed suspension PVC has the following characteristics: particle diameter of the resin 150 pm, its interior has a "multi-particle" structure, a particle size of 1 ~ 2 ^ xm, its particle structure similar to "pomegranate", that is the PVC resin particles the  vegetable stearic acid secondary particles are aggregated together, and in turn, the secondary particle diameter of 1 (K50 nm primary particles piled up each other. Overall though PVC is generally considered to be an amorphous polymer, but its interior is still containing 5% of the crystallites. of PVC carbon - chlorine bond strongly polar, this part of the crystallite melting point of up to 200 V or more, making a lot of crystallites do not melt in the process of this part of the base microcrystalline as physical crosslinking points in the role.
Second, the processing aids in the processing of condensed structure Evolution
At lower processing temperatures, the resin particles are used as mobile unit under the action of force and heat extrusion friction with each other, is destroyed gradually as the primary and secondary particles. When the temperature is higher than the glass transition temperature of PVC, the agglomeration of the polymer particles in the secondary  PVC foaming board stabilizer chain starts moving, and formed at the surface of the secondary particle entangled network structure three-dimensional space.
Intermolecular forces of PVC large capacity is low and the molecular chain exercise special PVC particles condensed structure to poor heat when heated; particle suspension stabilizer present on the surface film, the hard particles melt microcrystalline, Suspended particles makes it difficult to form an effective tangles. These factors lead to slow plasticized PVC, low melt strength, defective rate, seriously affecting the production efficiency and product quality. Research results show that even at the end of the extrusion molding, only 60 to 65% of the secondary particles to complete plasticization. Resulting PVC solid particles containing a secondary structure of the "filler material", in addition to the secondary particle entanglement of the segment during the cooling after the formation of a new ceramic, PVC heat stabilizer gives the unique structural features and performance.