PP Homopolymer

It is polymerized from a single propylene monomer, and the molecular chain doesn’t contain ethylene monomer, so the regularity of the molecular chain is high and strength is good. However, compared with PP copolymer, PP homopolymer has high crystallinity, poor impact performance, poor toughness, poor dimensional stability, easy aging and poor long-term heat resistance stability.

1. PP homopolymers can be processed using a variety of processes to produce a wide range of products. It can be extruded polypropulene granular of blowing grade, flat yarn grade, injection mulding grade, fiber grade and blown film grade.
2. Used for the production of packaging tapes, blowing bottles, brushes, ropes, woven bags, toys, folders, electrical appliances, household items, microwave lunch boxes, storage boxes, wrapping paper films.
3. Extruded products are the largest market of PP homopolymer, and textile fibers and monofilaments are the largest segment. Homopolymer Polypropylene has been the main material for making fibers. This is due to its tinting ability, abrasion and chemicals resistance properties and favorable economic conditions.
4. Injection moulding products are the second largest market of PP homopolymers, including containers, closures, automotive industry, household goods, toys and many other consumer products.
5. Homopolymer Polypropylene is also often used to produce blow-molded containers because of its good moisture barrier properties and sufficient clarity.

Molecular weight, molecular weight distribution, stereoregularity and additives are the main factors affecting the processability and physical properties of polypropylene homopolymer.

1. Molecular weight, usually expressed in flow rate.
2. Molecular weight distribution. It is usually expressed as the ratio of the weight average molecular weight to the number average molecular weight of the polymer, which is also known as the polydispersity index.
3. The molecular weight distribution of a polymer has a significant impact on its processability and end-use properties. This is because polypropylene in the molten state is shear sensitive. As the applied pressure increases, its apparent viscosity decreases. PP with a broad molecular weight distribution is more shear sensitive than PP homopolyer with a narrow molecular weight distribution. Therefore, materials with a broad molecular weight distribution are easier to process during injection molding.
4. Certain applications, especially fibers, require narrow molecular weight distributions.