Abstract: The invention relates to the field of physical foaming, in particular to C08J9/12. The method comprises the following steps: crosslink the foaming matrix to obtain a plurality of crosslinked prefabricated products, add the crosslinked prefabricated products into a reaction reactor filled with polar liquid, add nitrogen for foaming, relieve pressure, and heat for foaming to obtain the foaming materials. In the polar liquid system, the inventor finds that the ratio of the distance between the adjacent crosslinked prefabricated products to the thickness of the prefabricated products as well as the difference between the melting temperature of the polymer and the temperature of the polar liquid need to be controlled to promote the adjacent prefabricated products in full contact with the polar liquid, and prefoaming can be carried out under the condition of low temperature difference, namely, at the low temperature of the polar liquid.

Abstract: The invention relates to the technical field of physical foaming, in particular to an environmentally friendly, efficient and low-cost method for preparing physical foaming materials. The method includes the following steps: place plates to be foamed in a reaction kettle, inject permeable medium for soaking treatment, saturate in the inert gas, and then foam at the high temperature condition; the temperature of the high temperature condition is not less than 80 DEG C. In the method for preparing physical foaming materials in the invention, the plates are treated with water and other permeable media, and the kettle foaming process is adopted to shorten the saturation time, thereby greatly improving the foaming efficiency and the performances of the foaming materials such as pore size homogeneity, pore distribution uniformity and foaming rate.

Abstract: The present invention discloses a synthesis method of lactide by confinement effect catalysis of crystalline porous polymer material, wherein the method comprising: (I) synthesis of catalyst; (II) synthesis of lactide by confinement effect catalysis; and (III) purification of lactide. In the present invention, a yield of L-lactide by catalysis of L-lactic acid by crystalline polymers is as high as 85.6%, which is 10% higher than the yield of lactide by H-? molecular sieve reported in documents currently available; it is easy to prepare the crystalline porous polymer material catalyst, which is environmental friendly, has a high yield and is recyclable, for consecutive 7 times the catalysis yield is maintained to be higher than 70%, and catalysis yield conservation rate is far higher than catalysis effects of catalysts reported in documents currently available.

Abstract: The invention relates to the field of foaming technology, in particular to CO8G101/00. A method for preparing chlorinated polyethylene materials by supercritical foaming includes the following steps: (1) Add the chlorinated polyethylene material into the reactor, add water and foaming nucleating agent, and then close the reactor cover; (2) Heat to 50-80 degrees C.; (3) Inject supercritical carbon dioxide into the reactor, so that the chlorinated polyethylene material can achieve saturation adsorption of supercritical carbon dioxide; (4) Remove and treat the chlorinated polyethylene material at 100-150 degrees C. for 1-5 minutes. The preparation method is simple, environmentally friendly, efficient and low-cost, uniform micropores improve the elasticity of the foam material and reduce the density of the foam material, which is 0.2-0.3 g/cm3, and the foam wall is thin.

Abstract: The invention relates to a foaming process using carbon dioxide solution, comprising: put a parison into the carbon dioxide solution for primary foaming, remove and put the parison into the carbon dioxide solution for secondary foaming to get the foam product. Compared with foaming process using high-pressure gas directly, the foaming process using polar liquid system can get a uniform foam structure with high foaming rate faster, and has good foaming effect for high crystalline polymers. To control the change of temperature and pressure after the introduction of carbon dioxide, the impact and penetration of carbon dioxide on the surface of the crosslinked material can be controlled first, and the solubility of carbon dioxide in the polar system can be improved by further increasing pressure and temperature, thereby promoting the formation of uniform foam structure with high foaming rate in the subsequent heat foaming process.

Abstract: The present invention discloses a synthesis method of lactide by confinement effect catalysis of crystalline porous polymer material, wherein the method comprising: (I) synthesis of catalyst; (II) synthesis of lactide by confinement effect catalysis; and (III) purification of lactide. In the present invention, a yield of L-lactide by catalysis of L-lactic acid by crystalline polymers is as high as 85.6%, which is 10% higher than the yield of lactide by H-? molecular sieve reported in documents currently available; it is easy to prepare the crystalline porous polymer material catalyst, which is environmental friendly, has a high yield and is recyclable, for consecutive 7 times the catalysis yield is maintained to be higher than 70%, and catalysis yield conservation rate is far higher than catalysis effects of catalysts reported in documents currently available.