Study on Hydrolytic Degradation of Polyester and Polyamide in Basic Solutions at High Temperatures

Area of Science:

• Materials Science
• Polymer Chemistry
• Oil and Gas Engineering

Background:

• Temporary plugging materials are vital in oil production but face limitations like poor temperature resistance and complex manufacturing.
• Existing materials struggle with high-temperature applications, necessitating the development of advanced barrier materials.
• Understanding hydrolysis mechanisms in polymers like poly (butylene terephthalate) (PBT) and polyamide 6 (PA6) is key to designing improved plugging agents.

Purpose of the Study:

• To design and prepare a PBT/PA6 blend with enhanced hydrolysis characteristics for high-temperature applications.
• To investigate the physicochemical synergistic effects between PBT and PA6 during hydrolysis.
• To propose a new material design strategy for significantly enhancing degradation rates in temporary plugging agents.

Main Methods:

• Extensive study of aliphatic polyesters, polyamides, and thermosetting resins' hydrolysis at various temperatures.
• Analysis of hydrolysis mechanisms for representative poly (butylene terephthalate) (PBT) and polyamide 6 (PA6).
• Design and preparation of a PBT/PA6 blend using PBT as the continuous phase, inspired by wood decay etching effects.

Main Results:

• PBT/PA6 blends exhibit significantly faster hydrolysis at 120 °C compared to pure thermoplastic polyesters.
• A synergistic effect was identified: PA6 hydrolysis releases amine groups that catalyze PBT hydrolysis, while PBT etching accelerates PA6 hydrolysis.
• The developed PBT/PA6 blend demonstrates enhanced degradation rates due to integrated physical-chemical synergistic effects.

Conclusions:

• The PBT/PA6 blend offers a promising solution for temporary plugging materials requiring higher-temperature resistance and controlled degradation.
• The study highlights the effectiveness of leveraging synergistic physicochemical effects in polymer blends for material design.
• This innovative approach significantly enhances material degradation rates, addressing limitations of current plugging agents in the oil industry.