In recent years, many units at home and abroad have been active in the research of PP Foaming Nucleating Agent, and there are many kinds of commercialized nucleating agents, among which sorbitol derivatives and organic phosphates have significantly improved the transparency of PP. At present, sorbitol derivatives have become a kind of nucleating agent with the most active development, the most varieties and the largest production and sales volume at home and abroad.
The development and application of nucleating agents are developing rapidly in China, and the variety and output have increased to a certain extent. The price of domestic research and development of nucleating agents is far lower than that of foreign products, but the variety and quality stability need to be improved and improved. There is also a lot of work to be done in product structure and benefit scale. We should focus on the development and production of efficient and non-toxic nucleating agents as soon as possible A new auxiliary industry has been formed in China.
Its main directions are:
(1) Nucleating agent, as the modifier of polyolefin resin crystallization, can make plastic products have good processing and use performance. In order to give full play to the advantages of each nucleating agent, the development direction in recent years is mainly the compounding of nucleating agent. The nucleation of inorganic, organic or different structures has significant synergistic effect, and multi-component compounding is an important trend in the development of modern polymer auxiliaries. The research field of composite nucleating agent is very active, for example, adding sorbitol derivative and its auxiliary components to improve the transparency of PP; adding sorbitol derivative and other functional additives, such as organic phosphorus antioxidant, fatty acid and esters, can obtain transparent PP with excellent comprehensive performance. Clarifexy 800 is a compound transparent agent made of acid, ester, salt and other organic compounds. The development of compound nucleating agent is not limited to the simple mixing of several kinds of substances, but also can design the nucleating agent molecules to have other functions. Such products are emerging. For example, the sulfur-containing substituents on the two benzylidene rings of sorbitol derivatives are improved to make them highly efficient, transparent and have the performance of oxidation resistance and degradation. Australia has successfully developed liquid composite nucleating agent for polyolefin, which will become one of the hot spots in the research and development of nucleating agent in the 21st century.
(2) In addition to maintaining the good comprehensive properties of α – nucleating agent, β – nucleating agent also has good toughness. Its elongation at break and notched impact strength are several times higher than α – nucleating agent. The hot deformation temperature can be increased by 10-25 ℃, melting point reduced by 15 ℃, and α – nucleating agent can be transformed into β – nucleating agent. The high rigidity, high toughness, high heat resistance and other high properties of the special PP nucleating agent have a good application prospect. At present, the only way to produce commercialized β – crystalline PP is to add β – nucleating agent, which is also a new field and hot spot in the development and research of nucleating agent technology.
(3) Polymer nucleating agent will become one of the main directions of research and development of PP nucleating agent technology because there is no problem of uneven dispersion of additive nucleating agent.
(4) Sorbitol derivatives, carboxylic acid metal salts, organic phosphates, rosin acid salts and other nucleating agents have their own advantages and disadvantages in the application of PP. Sorbitol derivatives should be the main nucleating agents in China, but the purity of products should be improved, the residual free aldehydes in the synthesis process should be reduced, and the peculiar smell should be reduced. Organophosphate and rosin acid nucleating agents have the characteristics of improving the transparency and rigidity of PP, and they are non-toxic and tasteless. Therefore, the research and development of these two nucleating agents should be strengthened
