When selecting TPE varieties, the following points should be noted:

  1. Common TPE compatibilizer

The addition of compatibilizer can improve the compatibility between TPE and resin when the compatibility between TPE and resin is poor. Common compatibilizers include resin or TPE compatibilizers such as maleic anhydride or acrylic acid graft copolymers.

  2. Good compatibility between TPE and resin

  1. Similar polarity principle

The polarity of plastics is as follows: cellulose plastics>PA>PF>EP>PVC>EVA>PS>PP, HDPE, LDPE, LLDPE;

The polarity of TPE is as follows: rubber>丁腈橡胶>氯丁橡胶>丁苯橡胶>顺丁橡胶>天然橡胶>乙丙橡胶;

When selecting, the polarity should match and correspond, that is, high polarity resins should be selected with high polarity TPE, and low polarity resins should be selected with low polarity TPE.

  2. Dissolution parameter相近原则

When selecting, the difference in dissolution parameters between resin and TPE should be less than 1.5 to ensure good compatibility.

  3. Synergistic effect of TPE

Different varieties of TPE often have synergistic effects when added together, such as in the PP toughening formula, the toughening effect of EPDM and ABS is good.

  4. Quantity of TPE

The amount of TPE is not the more the better, and there is usually an optimal value. For example, in the PVC, the maximum amount of MBS is 15%, and the maximum amount of TPE in PS is 15%.

  5. Compensation for rigidity

When TPE is used as a toughening material for resin, its tensile strength, bending strength, and other rigidity indicators are significantly reduced. In order to compensate for the loss of rigidity, fillers such as calcium carbonate should be added to the formula, and organic resins such as AS and PMMA should be added to the TPE toughening system.

  6. Synergistically adding processing aids

For TPE with a large amount of added toughening formula, in addition to ACRTPE (ACR has a core-shell structure of acrylic ester copolymer), the viscosity of the melt can be increased. Therefore, it is necessary to add lubricants or processing aids to improve its processing performance.

  7. Particle size

The particle size of TPE has a great impact on toughening effect. According to the toughening theory of TPE, the particle size of TPE for brittle resins such as PS and PP can be relatively large; for more flexible resins such as PVC, POM, PET, the particle size of TPE can be relatively small.

In addition, the particle size of TPE has a great impact on the surface gloss of the product. When TPE is added to HIPS, the particle size is 2-5 microns, which produces a diffuse effect on the surface of the product. If the particle size of TPE is less than 0.5 microns, the surface gloss of the product is better.

  8. Other factors to consider

When the product needs to be transparent, MBS should be selected; when the product needs to be flame retardant, CPE should be selected; when the product needs to be weather-resistant, CPE, ACR, EVA should be selected, and MBS, ABS should not be selected; when the product requires low cost, CPE and EVA should be selected, and the price order of different TPE is MBS>ACR>ABS>NBR>CPE>EVA.