Meaning
High-boiling liquids are incorporated into polymer formulations to increase flexibility, workability, and distensibility. Applying plasticizers to rigid resins like polyvinyl chloride converts them into flexible compounds suitable for tubing or gaskets. These additives function by inserting themselves between polymer chains, increasing the free volume and lowering the glass transition temperature.
Processing Performance
Melt viscosity decreases when these compounding ingredients are added to the resin mix. This change allows for lower processing temperatures and reduces the mechanical load on the injection moulding screw. However, the compounder must balance the amount added to prevent screw slippage and inconsistent shot sizes.
Material Durability
Formulated parts can suffer from additive migration over extended service lifetimes. In high-temperature environments, the low molecular weight additives may volatilize or leach into surrounding media. This loss of additive causes the moulded part to become brittle and prone to cracking under mechanical stress.
Formulation Strategy
Sourcing decisions require careful evaluation of the molecular weight and volatility of the chosen compound. High-molecular-weight polymeric variants are selected when long-term stability and extraction resistance are required for demanding industrial applications. These choices directly affect the raw material economics of the compound, and they determine whether the finished moulded part can meet strict industry standards for low outgassing and chemical resistance.
