Properties and application of
Acrylic Impact Modifiers Because acrylate is the "core-shell" structure of the elastomer, give it a series of advantages: excellent impact resistance "core-shell" structure of the impact performance is better than the network structure of polymer (CPE, EVA). In terms of glass transition temperature, CPE is -10℃ ~ -20℃, while acrylate can reach -56℃, so low temperature impact performance is significantly better than CPE. The newly developed TIM812 glass transition temperature can reach above -60℃, improving the low temperature impact performance of profiles significantly.
CPE processing temperature range is narrow because of the
Chlorinated Polyethylene structure
Close to PVC, high temperature (185℃), good incorporation, easy to damage the network structure, resulting in impact resistance
Drop. If the temperature is low, plasticizing is not good, poor dispersion, but also affect the impact, appearance and other properties of propylene
Acid ester anti-
Impact Modifier does not have the above problems, processing temperature is wider, easy to operate, high yield, stable production
Low thermal shrinkage, good dimensional stability using A C R impact modifier P V C profile general 100℃, 60 minutes of low shrinkage, generally below 1.5%. CPE is higher, generally above 1.5% (standard requirements ≤2.5%). The practical significance of this project is to test the longitudinal stress of P V C profiles. The influence factors of longitudinal stress are the gelation degree of plasticization and the speed of process traction. Therefore, the residual stress between molecules is too large, and the local concentration is more concentrated, which is the main reason of stress cracking of P V C profile. The ACR resistance
The impact modifier has obvious effect on improving the stress cracking of profiles, and the cracking is less in low temperature assembly. ACR impact modifier has a reasonable physical structure, so the processing range is wide, extrusion speed is fast, suitable for high shear speed, suitable for high speed extrusion. Low melting temperature, and good fluidity, can save A C R flow modifier, reduce the cost.
Good surface gloss Because ACR is easy to plasticize, low melt strength, high gelation, so the product surface gloss is high. The results show that the general glossiness is between 20% ~ 40% when modified by CPE, while the glossiness can reach 40% ~ 65% after modified by A C R, and the product is smooth and delicate with good hand feel.
The application of ACR improves the plasticizing performance and improves the performance of PVC profile. In addition, due to wider processing temperature and strong adaptability, the welding strength is improved, so the welding Angle strength is significantly improved.
The weather resistance of PVC profile is improved. At present, different degrees of gray and yellow phenomenon occur in PVC profile using CPE anti-impact system, which has a direct relationship with C, P and E. After uv irradiation, the whiteness of CPE can reach 50%, while the whiteness of ACR can only change 30%.
Therefore, it seriously affects the appearance color change of PVC profiles. The use of A C R is an important way to improve weather resistance and anti-photoaging discoloration
