Introduction of additives for biodegradable plastics

Auxiliaries for biodegradable plastics are important associated industries for biodegradable plastics. In the face of the rapid development of biodegradable plastics production and demand in recent years, as a supporting agent for biodegradable plastics is facing unprecedented opportunities and challenges.

First, polylactic acid and other crystalline polyester supporting nucleating agents
As we all know, the crystallization behavior of crystalline polymers, including crystal form, crystallinity, crystallization rate, etc., directly determines the performance of the product. The addition of nucleating agents as a simple and efficient way to improve the crystallization properties of polymers has been accepted and paid attention to by more and more practitioners.
The crystallization behavior of semi-crystalline biodegradable polyesters such as polylactic acid (PLA), polyglycolic acid (PGA) and polyhydroxyalkylates (PHAs) has also become a research hotspot in the industry.
In recent years, talc powder, amide, hydrazide, carbon nanotubes, inositol, polyhedral oligomerization half-siloxane, calyparene, cyclodextrin, layered phosphonate and other nucleating agents have been reported in an endless number, but few mature and efficient industrial varieties have been reported. So far, the research on biodegradable plastic nucleating agents mainly focuses on inorganic materials, organic compounds, salts and polymer materials.
Second, inorganic material nucleating agent
Inorganic materials, as the most commonly used nucleating agents for biodegradable plastics such as polylactic acid, mainly include layered silicate compounds, inorganic salt compounds, inorganic nonmetallic oxides and carbon materials.
The use of talc as a PLA nucleating agent is often used as a standard to compare the potency of nucleating agents. As early as 1996, Kolstad et al. found that talc powder could significantly increase the crystallization speed of PLA. In 2003, Japanese scholar Nam et al. found that montmorillonite had a great impact on the crystal structure and crystallization rate of PLA, and adding low molar mass fatty acids would further increase the crystallization rate of polylactic acid. Zhao Xiuli et al. found that adding flax fiber to PLA can effectively promote crystallization. The team also found that PLA crystallized fastest when adding 1.5% nano CaCO3 and gaseous SiO2, forming a typical spherulite.
All in all, the biggest feature of inorganic material nucleating agents is that they are widely available, cheap and easy to obtain, and can promote the nucleation and crystallization of biodegradable plastics. However, due to its poor compatibility in the matrix polymer, it is easy to cause the performance of plastic products to decline or instability and other shortcomings limit its application range.