Polyamide Aramids Processability – Need for improvement in

Use of Plasticization method for Aramids

Aromatic polyamide (aramid) were the first linear polymers and are modern high-temperature resistant macromolecules which belong to the family of functionalized polyphenylenes. Aromatic polyamide show a high degree of crystallinity which makes it difficult to become soluble and processable. The structural modifications through chemical means are designed to modify or disturb the regularity and chain packing to impart better solubility characteristics. Synthetic modifications can be made by incorporating flexible linkages and ether groups into the main chain to improve solubility and processability and thermo-plasticity of aramids.

Polyamide is polymers having the amide bunch in their rehashing unit. The sweet-smelling nature of the polymer spine separates sweet-smelling polyamides from aliphatic polyamide. The sweet-smelling structure of the principal chain of the aramids assumes a significant job in giving certain extraordinary qualities, which are oxidative soundness, higher dissolvable safe, just as unrivaled warm and mechanical properties, subsequently they are likewise delegated elite materials. 

Aramid filaments have high quality and modulus with low thickness and high prolongation which grants high effect obstruction in the composites. Thus aramids are likewise utilized as a significant support material in aviation applications where high determination is required. One such application is a honeycomb structure which is used for auxiliary applications in avionic business because of diminished load without trading off mechanical quality. Also, the sap impregnated Nomex® paper honeycomb structure is ordinarily utilized as a plane inside material because of its phenomenal combustibility attributes.

Aramids due to the presence of aromatic rings show high viscosity and high glass transition temperature (Tg). Aromatic polyamides are infusible and insoluble in organic solvents like other aromatic and heterocyclic polymers. Therefore, a lot of research has been conducted in terms of chemical routes, for modification of backbone and aromatic polyamide structures to improve solubility and hence processability without the expense of mechanical properties.

Another attractive synthetic approach to achieve structural modifications is the incorporation of bulky substituents as pendant groups along the polymer backbone. If the pendant groups are carefully chosen, it is possible to promote solubility without impairing thermal and mechanical properties to a great extent. To improve the processability of aramids, such bulky groups should be added which can eliminate or reduce the problematic features of aramids due to which it faces difficulty in processing. Addition of such bulky groups is required that must have:

  1. Enhanced solubility 
  2. Reduced viscosity 
  3. The lower glass transition temperature  
  4. Easy to process

For this approach of synthetic modification, HBPs draw much attention as blend components, additives, and plasticizers. The high functionality, through which the properties can be tailored, along with high solubility and low viscosity, are excellent prerequisites for HBP’s use as plasticizers in aramids.

The purpose is to synthesize and investigate the blend composition of aramid and hyperbranched polymer, and optimize properties to obtain maximum solubility characteristics in aramids and obtain ease of processability.

Blend formation of aramids and hyperbranched polymers (HBPs), where HBPS is used as a plasticizer; provide combined and improved properties of both HBPs and aramids. Effect of plasticization of HBPs on aramids has brought out interesting findings and improved properties in aramids which have increased applications of aramids as blends and has motivated research in the field of HBPs and blend studies.

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