The invention relates to a recycled
polypropylene modified plastic and a preparation method thereof, belonging to the technical field of modified materials. The plastic comprises 100 parts of recycled
polypropylene, 15-20 parts of a
toughening modifier, 1-1.5 parts of an initiator, 3-5 parts of a compatibilizer, 1-2 parts of an
antioxidant, 1-2 parts of a light stabilizer and 2-3 parts of a
lubricant in parts by weight; wherein the
toughening modifier has good compatibility with a recycled
polypropylene resin matrix, forms a soft connection between
silicon dioxide and the recycled polypropylene resin, and is beneficial to improving the
toughening effect of
silicon dioxide; secondly, the toughening modifier can be grafted onto a recycled polypropylene molecular chain under the action of the initiator, thereby increasing the degree of branching; finally,
hydrogen bonds exist between
amide structures on the
branch chains; when an external force acts on the recycled polypropylene
resin matrix, the
hydrogen bonds are preferentially dissociated, thereby weakening the influence of the external force on the main chain, effectively alleviating the
stress concentration phenomenon; meanwhile, the
hydrogen bonds can be formed again at
room temperature, thereby realizing self-healing ability.