Hikaru Saijo

Filler-Reinforced Poly(Glycolic Acid) for Degradable Frac Balls Under High-Pressure Operation

The mechanical strength and degradability of chopped glass fiber (GF)- and glass powder (GP)-reinforced poly(glycolic acid) (PGA) were investigated. A loading of 30 wt% GF improved the tensile and compressive strength of PGA by 20–100 %. The reinforcement depended on the interface adhesion between the GF and PGA matrix, and the aspect ratio and orientation of the fibers. The GP did not improve the tensile strength of PGA, whereas the composite containing 30wt% GP exhibited 20–40 % higher compressive strength than PGA. The ball made of PGA/GP composite showed a higher pressure capability than PGA, and the improvement appeared to be related to the increase in the compressive strength of the material. The degradability of the PGA/GP composite is similar to that of PGA, and the rate of the degradation is predictable in the same manner as PGA. These findings suggest that frac balls consisting of GF or GP-reinforced PGA are suitable for high-pressure high-temperature operations.