How to use the right additives to make PP modification achieve the effect you want?

1. The choice of additives

(1) Choose additives according to the purpose to be achieved

Choose suitable additives according to the purpose to be achieved, and the additives added should be able to give full play to their expected effects and reach the specified indicators. The prescribed index is generally the national standard, international standard of the product, or the performance requirement put forward by the customer.

The specific selection range of additives is as follows:

Toughening-choose elastomers, thermoplastic elastomers and rigid toughening materials;

Reinforcement-select glass fiber, carbon fiber, whisker and organic fiber;

Flame retardant-bromine (common bromine and environmentally friendly bromine), phosphorus, nitrogen, nitrogen/phosphorus composite intumescent flame retardant, antimony trioxide, hydrated metal hydroxide;

Antistatic-all kinds of antistatic agents;

Conductivity-carbon (carbon black, graphite, carbon fiber, carbon nanotube), metal fiber and metal powder, metal oxide;

Magnetism-ferrite magnetic powder and rare earth magnetic powder include three types of samarium cobalt (SmCo5 or Sm2Co17), neodymium iron boron (NdFeB), samarium iron nitrogen (SmFeN) and alnico powder;

Thermal conductivity-metal fibers and metal powders, metal oxides, nitrides and carbides; carbon materials such as carbon black, carbon fibers, graphite and carbon nanotubes; semiconductor materials such as silicon and boron;

Heat resistance-glass fiber, inorganic fillers, heat-resistant agents such as substituted maleimides and β crystal nucleating agents;

Transparent-nucleating agent, Millad 3988, a sorbitol series of α crystal nucleating agent, works best for PP;

Wear resistance-graphite, molybdenum disulfide, copper powder, etc.;

Insulation-calcined kaolin;

Barrier-mica, montmorillonite, quartz, etc.

(2) Additives are selective to resin

The nucleating agent has a good effect on copolymerized polypropylene; the heat-resistant modification of glass fiber has a good effect on crystalline plastics, but has a poor effect on amorphous plastics; carbon black is filled with conductive plastics and has good effects in crystalline resins.

2. The form of additives

The additives of the same composition have different forms, which have a great influence on the modification effect.

(1) The shape of the additive

The reinforcing effect of fibrous additives is good. The degree of fiberization of the additives can be expressed by the aspect ratio. The larger the L/D, the better the reinforcement effect. This is why we add glass fiber through the vent hole. The molten state is better than the powder state to maintain the aspect ratio and reduce the probability of fiber breakage. The spherical additives have good toughening effect and high brightness.

(2) Particle size of additives

The smaller the particle size, the more beneficial the tensile strength and impact strength of the filled PP modified plastic material.