PVC, properties

Table 3.10 displays three examples of PVC properties according to the degree of plasticization. 

Another way to vary PVC properties is to add in other polymers such as ABS, SAN, MMA, and nitrile rubber. These mixtures will improve the processibility and the impact resistance of the rigid PVC products. 

In addition to controlling the recipe materials and PVC properties including molecular weight and molecular weight distribution, the major processing considerations are ... 

PVC crystalline structure and morphology are discussed in detail in FVC Degradation Stabilization Here we include only limited information essential for understanding its influence on PVC properties. 

Chem. Descrip. Proprietary Uses Defoamer for latex and emulsion PVC Properties Liq. water-disp. 100% solids Bevaloid2512 [RhodiaHPCII]... 

The variety of products reflects the value of basic PVC properties. The widely recognised versatility of PVC stems from the many forms in which the polymer can be made and from the fact that each form can be compounded further to alter its properties. In PVC compounding, the interaction of additives with the polymer is a complex matter depending upon the structure of PVC and the structural changes during the fusion process. When heat and shearing forces are applied to PVC, molecular deformation flow and particle flow take place. Such a flow is called particle slippage. 

Relationship Between Phthalate Type and Flexible PVC Properties... 

PVC properties depend on the ratio of PVC powder/plasticizer. Increasing plasticizer levels improve the flexibility at the detriment of the already weak dielectric properties. Plasticizer also reduces the flame retardancy of PVC. 

The type of plasticizer and its interaction with PVC is important in selecting the polymer/plasticizer ratio (28). The PVC properties which affect this interaction are size distribution structure, shape, porosity of particles molecular weight and distribution of PVC and other chemicals used in the compounding recipe. Plasticizers are usually added in amounts greater than 20 parts per hundr parts of resin (phr). The reverse effect, unplasticization, is observed at lower concentrations. For most resin-plasticizer combinations at room temperature, a plasticizer threshold concentration must be passed before the normal plasticizer has an effects on physical properties. The extent to which Tg is depressed depends on the amount of plasticizer present. The usual concentration range for plasticizers is 20-85 phr. 

Figure 4. The effect of filler particle size on PVC properties.

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