Application of ACR impact modifier
Due to its excellent insulation, noise reduction, sealing and other characteristics PVC plastic doors and windows have been widely used especially in cold areas. However,after years of use also PVC plastic windows revealed some weaknesses, such as low temperature impact resistance, cracking, aging discoloration and other issues.The acrylic impact modifier is needed.
Why to choose acrylic impact modifier?
1, compatibility with PVC resin should be moderate, if the compatibility is too large, two completely molecular mixture, impact modifier may play a role as a plasticizer, and PVC molecules are closely attached, leaving the impact Force directly on the PVC chain, can not improve the role of anti-impact. On the contrary, if the compatibility between the two is too small to achieve uniform dispersion, the adhesion to PVC is lost and the impact can not be absorbed.
2, Lower glass transition temperature which can improve the impact resistance of PVC at low temperature.
3, High molecular weight, if necessary, the best light cross-linked to enhance the enhancement effect.
4, weatherability should be good, small mold expansion.
5, good blends with PVC technology.
6, heat resistance (resistant to deformation, thermal stability) is better.
Properties and Application of Acrylic Series Impact Modifier
As acrylate is a "core-shell" structural elastomer, giving it a series of advantages:
Excellent impact resistance
The impact resistance of "core-shell" structure is better than network structure polymer (CPE, EVA). As far as the glass transition temperature is concerned, the CPE is -10 ° C to -20 ° C, while the acrylate is up to -56 ° C, so that the low-temperature impact performance is obviously superior to that of CPE. The latest development of the TAE-858 glass temperature up to -60 ℃ above, to improve the profile low temperature impact performance is significant.
A wide range of processing technology, operation process and stability
CPE processing temperature range is narrow, because the structure of PVC and PVC close, high temperature (185 ℃), good mixing, easy to damage the network structure, resulting in decreased impact resistance. If the temperature is low, poor plasticization, poor dispersion, but also affect the impact, appearance and other properties, and acrylic impact modifier does not exist the above problems, processing temperature is wide, easy to operate, high yield, stable production Good sex.
Lower thermal shrinkage, dimensional stability
Good use of ACR impact modifier P V C profiles generally 100 ℃, 60 minutes lower shrinkage, usually below 1.5%. The CPE is higher, generally more than 1.5% (standard requirements ≤ 2.5%). The practical significance of this project is to test the longitudinal stress of PVC profiles. The factors affecting the size of longitudinal stress are the degree of plasticizing gel and the speed of the process traction. As a result, the residual stress between molecules is too large, and the local is more concentrated, which is the main reason for the stress cracking of PVD profile. The use of ACR impact modifier to improve the profile of the stress cracking has a significant role in the low temperature assembly cracking less.
Suitable for high-speed profile extrusion, and the role of flow modifier
ACR impact modifier physical structure is reasonable, so a wide range of processing, extrusion speed, to adapt to the higher shear rate, suitable for high-speed extrusion. Low melting temperature, and good fluidity, can save A C R flow modifier, reduce costs.
Product surface gloss is good
Due to ACR easy plasticization, low melt strength, high degree of gel, so the product surface gloss. Experiments show that modified with CPE, the general gloss of 20% to 40%, and after the use of A C R modified, the gloss can reach 40% to 65%, the product is smooth and delicate, feel good.
Improve the welding strength
As the ACR after the application of improved plasticizing properties, so that the performance of the PVC profile body, the other due to a wide processing temperature, adaptability and improve the welding strength, thus significantly improving the strength of the welding.
Improve the weather resistance of PVC profiles
At present, the use of CPE impact-resistant PVC profiles have varying degrees of gray, yellow phenomenon, which has a direct relationship with the CPE. The whiteness of CPE changed greatly after irradiation with ultraviolet light, reaching 50%, while the change of ACR was only 30%. So seriously affect the appearance of PVC profiles color change. Using ACR is an important way to improve weathering and anti-aging properties.
Contact Shandong polymer additives for more information.