Views: 88 Author: Site Editor Publish Time: 2022-09-19 Origin: Site
Due to its low price, excellent transparency and elasticity, good strength, good degradation properties, and gas barrier properties, PVA is increasingly used in various fields. As one of the simple and effective methods to improve material properties, composite modification has always been a research hotspot in the field of polymer materials. PVA is made into a highly absorbent sponge material, and a large number of closed-cell pore structures such as air, carbon dioxide, or other gases are formed inside, so what is the performance of PVA material? Let's take a look next.
Here is the content list:
l Low density and lightweight
l Good shock load absorption and good mechanical properties
l High specific strength
l Good thermal insulation
l Good sound insulation
Since the water-absorbing PVA sponge material contains a large amount of gas (air, carbon dioxide, etc.), its density is very small, generally a fraction or even several tenths of the density of plastics prepared from similar resins.
When the water-absorbing PVA sponge material is subjected to an external load, the internal gas will be compressed due to the extrusion effect, thereby resulting in a stagnation phenomenon. This stagnation and rebound phenomenon can consume part of the applied load so that the absorbent sponge can obtain excellent impact resistance.
The ratio of the strength to the relative density of the PVA material can be defined as the specific strength of the material, which represents the physical properties of the material. The specific strength of foamed materials with micropores and small pores is very high. Due to the small density of water-absorbing sponges, although the mechanical strength of water-absorbing PVA1799 sponge materials usually decreases with the increase of foaming times, in general, water-absorbing sponges the specific strength is still much higher than other materials of the same resin.
As a composite material with gas as the filling medium, the water-absorbing PVA sponge material needs to rely on the gas medium to conduct heat during the heat conduction process. Generally, the thermal conductivity of the gas is 1~2 orders of magnitude smaller than the thermal conductivity of the sponge itself, so the entire water-absorbing sponge's apparent thermal conductivity is relatively low. In addition, since the pores of the water-absorbent sponge can effectively prevent air convection, it is more beneficial to reduce the thermal conductivity of the water-absorbent sponge.
Similar to the thermal insulation effect, the plastic itself can absorb part of the energy of the sound wave, so that the sound wave cannot be reflected, and then play the role of noise reduction. In addition, when the sound wave reaches the surface of the PVA sponge material, the gas inside the plastic shrinks due to the additional load, and a stagnation phenomenon occurs, which consumes part of the energy of the sound wave impact.
The above is about the properties of PVA materials, if you are interested in PVA 1599, PVA 0599, PVA2488, PVA2688, PVA1799, Polyvinyl Alcohol Powder, you can contact us, our website is https://www.eastchem.com.cn/.