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What is polylactic acid?

Oct 18, 2018

A single lactic acid molecule has a hydroxyl group and a carboxyl group, a plurality of lactic acid molecules are together, -OH is dehydrated and condensed with -COOH of another molecule, and -COOH is dehydrated and condensed with -OH of other molecules, so that they are formed by hand. The polymer is called polylactic acid. Polylactic acid, also known as polylactide, belongs to the polyester family. Polylactic acid is a polymer obtained by polymerizing lactic acid as a main raw material, and the raw material source is sufficient and can be regenerated. The production process of polylactic acid is non-polluting, and the product can be biodegraded to achieve circulation in nature, so it is an ideal green polymer material.

Polylactic acid (H-[OCHCH3CO]n-OH) has good thermal stability, processing temperature of 170-230 ° C, good solvent resistance, and can be processed in various ways, such as extrusion, spinning, biaxial stretching. , injection blow molding. In addition to biodegradability, products made of polylactic acid have good biocompatibility, gloss, transparency, hand and heat resistance. Polylactic acid (PLA) developed by Guanghua Weiye also has certain antibacterial and flame retardant properties. It is UV-resistant and therefore widely used in packaging materials, fibers and nonwovens. It is mainly used in clothing (underwear, outerwear), industry (construction, agriculture, forestry, papermaking) and medical and health fields.

Physical properties:

Density: 1.20-1.30 kg/L

Melting point: 155-185 ° C,

Intrinsic viscosity IV: 0.2-8 dL/g

Glass transition temperature: 60-65 ° C,

Heat transfer coefficient: 0.025 λ(w/m*k)

Mechanical properties:

Tensile strength: 40-60 MPa

Elongation at break: 4%-10%

Modulus of elasticity: 3000-4000 MPa

Flexural modulus: 100-150 MPa

Izod impact strength (no gap): 150-300 J/m

Izod impact strength (with gap): 20-60 J/m

Rockwell hardness: 88