Density reduction, time-cross-link

Time-Cross-Link Density Reduction for Use in Long Time Behavior Prediction... 

Processing stabilizer Also called a flow promoter. In thermoplastics they act in the same manner as internal lubricants where they plasticize the outer surfaces of the plastic particles and ease their fusion, but can be used in greater concentrations (about 5 pph). With TS plastics they are not reactive normally and therefore reduces the rate of interactions of reactive groupings by a dilution effect. Thus easier processing may be derived mainly from the reduction in the rate at which the melt viscosity increases. At the same time the overall cross-linking density is reduced. 

It is of interest that the phenomena discussed above are most clearly manifested for linear polymers. When passing over to cross-linked polymers (eg copolymers of styrene and divinylbenzene), the effect of the surface on the relaxation time becomes less perceptible as the network density increases. This is due to the fact fiiat the reduction in the mobility of large segment of the chains caused by cross-linking excludes them from participation in the relaxation process, thus leveling the effect of the surface on their mobility. 

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