How does PMDA participate in polyimide membrane synthesis?
PMDA is mainly made of polyimide membrane through a two-step polycondensation reaction with ODA:
1. Formation of polyamic acid (PAA)
In polar solvents (such as NMP, DMAc), PMDA undergoes a ring-opening addition reaction with aromatic diamines to generate a soluble polyamic acid (PAA) solution. This facilitates coating processing.
2. Thermal imidization film formation
The PAA solution is evenly coated on the substrate, and is dehydrated and closed through gradient heating (usually 200-350°C) to transform into an insoluble and infusible polyimide structure and form a dense film at the same time.
The PI film formed in this way：
High temperature resistance (long-term use temperature can reach above 200℃)
Low coefficient of thermal expansion (CTE)
Excellent dielectric properties
Better mechanical strength and flexibility
As a professional PMDA supplier, JAMMARK INTERNATIONAL TRADINGE(ZIBO) CO., LTD.. focuses on the production and quality control of pyromellitic dianhydride, and continues to provide polyimide material manufacturers with high-purity, stable batches of raw material support. In the future, we will continue to delve into the field of high-end electronic materials and provide reliable raw material guarantees for the development of the global PI film industry.
