A sufficient amount of an antioxidant or anti-aging masterbatch is applied to the modified plastic in order to provide it high weather resistance. Following testing, the test item is exposed to UV light from a xenon lamp for 1000 hours, or one year. Retention of tensile strength was 86%, and strength was 88%.
The plastic has a long life cycle, which lessens the influence of waste plastic on the environment's pollution. Xenon lamp UV radiation for 3000h, or three years, retains 74% of its impact strength and 71% of its tensile strength, respectively.
Modified polypropylene plastic's invention:
The use of toughener
One of the five general-purpose plastics, polypropylene has limited use in engineering plastics and structural materials due to its substantial molding reduction rate and rapid warping and distortion. The system is strengthened, adjusted, and added calcium carbonate. The composite material may attain a variety of typical mechanical qualities while being less expensive, increasing the range of uses for polypropylene.
caustic calcium carbonate activation
With the growing growth of the composite material sector, toughener producers have discovered that calcium carbonate serves as both a filler and a significant modifier. Calcium carbonate may be added to the polypropylene blending modification system to increase stiffness and heat resistance while lowering the rate of molding shrinkage and product raw material costs.
The toughening agent manufacturers advise using heavy calcium carbonate with a mesh size of 1000 or more, and putting it into a high-speed agitator after drying, the calcium carbonate is an inorganic filler and has poor compatibility with polypropylene, so activation treatment is required before use to improve the binding force between calcium carbonate and polymer molecular chains, improve the mechanical properties of filled polypropylene materials, and increase the
The impact strength of the system in the blending system grows fast at initially, increases slowly after 30 parts, and falls after 40 parts as the amount of activated calcium carbonate increases. The coupling agent can increase the impact of the substance by activating the calcium carbonate. Because the activated calcium carbonate particle surface's physical and chemical characteristics have altered and are now simpler to distribute in the matrix, the strength has increased. There will be an aggregation and buildup of inorganic particles when the calcium carbonate content surpasses a particular threshold, making the blending method ineffective. The structure develops internal flaws, which cause a deterioration in a number of mechanical qualities.Calcium carbonate dose should thus not be greater than 40 parts.
Effect of Toughener on Blending System
(1) PP is given exceptional toughness and good processability by using a toughening agent.
(2) The chemical structure of the toughening agent, which has high aging resistance, has no unsaturated double bonds.
(3) The toughening agent is fluid and compatible with polyolefins, and it has a narrow molecular weight distribution.
(4) A product's weld line strength and the dispersion impact of fillers can both be enhanced by good fluidity.
The impact strength and elongation at break of the system are significantly increased with the addition of toughener.
As can be shown, PP and activated calcium carbonate are compatible with the toughening agent, which also has a good toughening effect on PP. This is due to the narrow molecular weight distribution of the toughening agent and the longer side octyl group than the side ethyl group in the molecular structure, which can form a molecular connection point and function as a connection and buffer between the components, allowing the system to function when it is impacted. As impact energy is distributed and buffered, there is less chance that stress-induced crazes will turn into fractures, increasing the system's impact resistance.
The network structure generated by these connection sites can experience substantial deformation while the system is under tension, which causes a significant increase in the system's elongation at break. Since the performance of the toughening agent itself determines the tensile strength, flexural strength, and flexural modulus of the system, when the content of the toughening agent increases, the content of the toughening agent should be kept below 20%.
