What is polyester?
Polyeseter is made from a polymer that has a variety of applications and types. It is produced by esterification,the chemical reaction in which an alcohol reacts with an acid to form an ester. Polyethylene terephthalate (PET) is probably is probably the most common polyester. Polyester is also the main component of synthetic fibers. The advantages of polyester include its high strength, resistance to abrasion, resistance to chemicals, and resistance against weather. Polyester can also be engineered in different forms, with different chemical and physical properties, to suit the requirements of different applications. However, polyester has its drawbacks. For example, the fact that it’s a petroleum-derived material and production causes some environmental issues. What’s more, polyester is also not biodegradable, and can negatively impact the environment when not disposed properly. For these reason, the recycling and reuse polyester have attracted a lot of attention.
Virgin Polyester and Recycled Polyester
PET can be divided into Virgin Polyester and recycled polyester.
Virgin Polyester is polyester that is manufactured directly from petrochemical feedstocks. Recycled Polyester, on the other hand, is polyester recycled from polyester products that have been discarded (e.g. Plastic bottles, clothing, etc.). The main difference between them is the manufacturing process, and their environmental impact.
Recycling polyester has an environmental advantage over virgin polyester. The production process of recycled polyester reduces carbon dioxide emissions and saves energy. It also helps to minimize the environmental impact caused by plastic waste. The disadvantages of recyclable polyester include:
1) Mechanical properties:
Because it is made from petroleum-based materials, and hasn’t been through the recycling and use process, Virgin polyester has a molecular structure that is more intact, and as a result, usually better mechanical properties. Its tensile, impact and modulus of elastic properties are typically higher. In contrast, recycled polyester may be subjected to processes like heating, cooling and crushing, which can lead to a change in its molecular composition.
2) Durability:
Virgin polyester is usually more durable due to its integrity in molecular structure. This includes resistance to heat, chemical corrosion, and abrasion. Recycled Polyester, on the contrary, may contain degradation products as a result of the recycling process. This can reduce its durability if it is used for a long time or in certain environmental conditions.
Improvement of polyester properties by anti-hydrolysis agents and chain-extenders under high temperature and high humidity conditions
A common approach to improving the performance of recyclable polyesters is the addition of anti-hydrolysis agents. Hydrolysis is a chemical reaction that destroys the molecular structure of polyester, resulting in a loss of performance. Anti hydrolysis agents can prevent or delay this reaction from occurring, thus improving the stability and durability of the polyester.
Anti hydrolysis agents work by reacting with the hydroxyl or ester groups in the polyester molecular chain to form a more stable chemical bond, which prevents water molecules from reacting with the polyester molecular chain. This newly formed chemical bond is less susceptible to hydrolysis than the original ester bond, thus improving the stability and durability of the polyester.
see more about application of anti-hydrolysis agent in polyester
testing data of PET added with anti-hydrolysis agent
Langyi has extensive experience in the production, development and application of carbodiimide anti-hydrolysis agents. We have over 10 years of R&D experience and successfully developed high purity and high activity carbodiimide anti-hydrolysis agents, including monomer type, polymerization type, liquid type, masterbatch type, etc. These products have shown excellent performance in various applications and have been widely recognized and praised by users.
