Application of Polyethylene Glycol

1. Insertion and plasticizing effect of molecular chains: Polyethylene glycol 400 belongs to low molecular weight polyethylene glycol, and its long-chain molecules can be inserted into the three-dimensional network structure formed after resin curing, playing the role of flexible chain segments. These segments act like plasticizers in the resin matrix, reducing the degree of tight packing between resin molecular chains and enhancing their activity, thereby reducing the brittleness of the cured resin and improving its toughness, impact resistance, and cold resistance.

2. Stress dispersion and energy dissipation: When the resin material is subjected to external impact, the segments of polyethylene glycol 400 embedded in it can effectively disperse stress and avoid rapid crack propagation. They can deform under stress, absorb and consume some of the impact energy, thereby suppressing the generation and development of internal cracks in the material and enhancing the fracture resistance of the cured resin.

3. Microphase separation and interface modification: If the resin system contains fillers or other reinforcing materials, polyethylene glycol 400 can promote good wetting and dispersion between the resin and fillers, optimizing the interface bonding between the two. This micro level phase separation structure helps to form a continuous and resilient resin phase around the filler, further enhancing the overall impact resistance of the composite material.

4. Adjusting crosslinking density and network structure: Although polyethylene glycol 400 generally does not directly participate in the resin curing reaction, in some cases, its hydroxyl functional groups may have weak interactions with certain components in the resin system, such as forming hydrogen bonds or slight crosslinking. This is helpful for adjusting the crosslinking density and pore structure of the resin network. Appropriate crosslinking density and more uniform network structure are beneficial for improving the toughness of the resin and preventing embrittlement caused by excessive crosslinking.

Polyethylene glycol 400 can play a toughening role in the resin curing process through various mechanisms, improving the mechanical properties of the cured resin, especially its ability to resist impact, bending, and low-temperature cracking.