Introduction to PPS Plastics

- May 03, 2019-


Introduction to PPS Plastics (polyphenylene sulfide)


  English name: Phenylenesulfide specific gravity: 1.36 g / cm 3 Molding shrinkage: 0.7% Molding temperature: 300-330 ° C. It is a thermoplastic special engineering plastic with excellent comprehensive performance. Its outstanding features are high temperature resistance, corrosion resistance and superior mechanical properties. PPS is a sulfur-containing aromatic polymer. The linear PPS is crosslinked at 350 ° C or higher to form a thermosetting plastic, and the branched structure PPS is a thermoplastic.

The world's top five PPS producers are Phillips, Toray, Ticona, Polyplastics, and Dainippon Ink.

  

  PPS plastic (polyphenylene sulfide): is a thermoplastic engineering plastic containing phenylthio group in the main chain of the molecule, and is a polyether plastic. The molecular structure of pps can be seen as a linear or slightly branched polymer composed of alternating benzene rings and sulfur atoms. The molecular chain gauge is strong in integrity and is connected by a rigid benzene ring and a flexible thioether chain. The primary bond has the characteristics of rigidity and flexibility, so pps can be crystallized and has a high melting point; secondly, the benzene ring forms a conjugation with a sulfur atom. And the sulfur atom is not yet saturated, after oxidation, the thioether bond can be changed into a sulfoxide group, or the adjacent macromolecules can form an oxygen bridge branching or cross-linking, so that the thermal and oxygen stability is very prominent; third, due to sulfur The polarity of the atom is bound by the benzene ring and the high crystallinity, which makes the pps non-polar or weakly polar. Therefore, the electrical insulation, dielectric properties and chemical resistance of pps are also prominent. Fourth, because pps has good compatibility with many polymers and additives, it can be modified by various means to improve its mechanical properties and other properties.


  PPS is a white powder with an average molecular weight of 0.4-0.5 million and a density of 1.3-1.8 grams per cubic centimeter. The pps have very interesting thermal properties. The thermal performance index enhanced by glass fiber is higher, its continuous use temperature reaches 400 degrees, the thermal stability of pps is excellent, the weight loss is not obvious when heated to 500 degrees, and it will completely degrade when it is 700 degrees. Its mechanics The performance decreases little with the increase of temperature. After 5,000 degrees of heat aging for 5000 hours, the flexural strength and tensile strength can be maintained above 50%. The tensile strength and flexural strength of pps are moderate in engineering plastics, but the elongation and impact strength are very low. Therefore, the use of pps in the stressed members is usually added with additives such as glass fiber, carbon fiber, filler, etc. To enhance its mechanical properties, pps through this modification, the main mechanical properties, such as tensile properties, bending resistance, compression and impact strength have been greatly improved, elongation has decreased, modified pps energy It maintains high mechanical properties and dimensional stability under long-term load and heat load, so it can be used in high-temperature stress environments.


  The dielectric constant of pps is very small, the dielectric loss is quite low, the surface resistivity and volume resistivity are not sensitive to changes in frequency, temperature and humidity. It is an excellent electrical insulating material, and its resistance to electric fox is also longer, pps The chemical stability is quite good. Besides being attacked by strong oxidizing acids such as concentrated sulfuric acid, concentrated nitric acid and aqua regia, it is not attacked by most acid-base salts and has chemical stability close to that of PTFE. When it is less than 175 degrees, it is insoluble in any known organic solvent, and pps does not crack plastic parts when it is in contact with a common organic solvent.


   PPS plastic (polyphenylene sulfide): Since the molecular chain is composed of alternating benzene rings and sulfur atoms, it has a flame retardant effect, and it can reach the UL-94-VO level without adding a flame retardant. Its limiting oxygen index can reach 44%-53%, similar to pvc, is a self-extinguishing plastic, pps is also very stable to ultraviolet rays, rays, etc., and does not stick or decompose on the surface when irradiated.

The main disadvantages of pps are poor toughness, low impact strength, and insufficient melt viscosity.


  If you need to know more about PPS engineering plastic material or want to find a reliable PPS plastic injection mould and moulding manufacture , Asia Billion can be your first choosing, contact us freely at:

Asia Billion Innovational Technology

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