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Preparation and the Application Study on the β-form Nucleating Agent of Polypropylene

Author: LiuXiaoXia
Tutor: ZhangPuYu
School: Henan University
Course: Polymer Chemistry and Physics
Keywords: Polypropylene Nucleating agent Amide α crystalline form β crystal
CLC: TQ325.14
Type: Master's thesis
Year: 2007
Downloads: 429
Quote: 2
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Abstract

Polypropylene (PP), its mechanical properties, non-toxic, low relative density, chemical resistance, and low cost, easy processing molding excellent characteristics, synthetic resin, the fastest-growing and most active new product development one of the species . However, since the polypropylene itself a number of deficiencies, such as impact poor performance, poor tensile strength, heat resistance and the ability to resist the external force, largely limits the application of polypropylene material. In recent years, modified polypropylene as the main direction of development of polypropylene, by adding the nucleating agent the crystallization behavior and the crystal morphology of the control polypropylene, so as to achieve the purpose of improving properties of polypropylene, to create the performance of the polypropylene product, it is very effective practical means of regulation. β Crystalline Polypropylene has a high impact strength, broaden the application space of polypropylene toughening modification. Add β nucleating agent is now recognized as the most effective way to get high levels of β Crystalline Polypropylene. This article is designed and synthesized a series of amide-type β nucleating agent, screening efficient, stable and practical amide-type β-nucleating agent polypropylene impact test performance significantly improved; by virtue of the WAXD study the nucleating agent nucleation effect, and studies of the crystal structure of the nucleating agent nucleation effect; amide-type β nucleating agent role isotactic polypropylene crystallization behavior and micromorphology With DSC, POM, the amide-type β nucleating agent-induced iPP crystallization process in line with the epitaxial crystallization mechanism. The study found that NA-1, the NA-2, Na-3, NA-4 polypropylene toughness have different degrees of improvement, wherein NA-1 and NA-2 of the improving effect is more obvious. Rosin-based nucleating agent on the mechanical and optical properties of polypropylene have improved to varying degrees: 1. NA-1β nucleating agent on the crystalline properties of polypropylene. The modified polypropylene mechanical performance tests show that the nucleating agent polypropylene toughening excellent performance. Using differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) were characterized by their crystalline form. DSC studies show that the nucleating agent added can be induced in polypropylene α crystal transformation to the β crystal; found that the X-ray diffraction studies, as a nucleating agent is added in an amount of 0.3%, the content of the β-crystal form is 87% can be achieved, and DSC Study results are consistent. Investigated the influence of the cooling rate on the crystallization temperature and the crystallization peak temperature, experiments show that the nucleating agent is added to the crystals to high temperature offset, the crystallization speed. Investigated the NA-2 as β nucleating agent on the the polypropylene mechanical properties and crystallization properties. Mechanics research results show that the nucleating agent polypropylene toughening excellent performance, when 0.3%, the impact strength from 36.06J/m2 to 65.79 J/m2, nearly doubled. DSC studies have shown that adding β nucleating agent can be induced by the PP in β crystal generation. Investigated the influence of the cooling rate on the crystallization temperature, when the cooling rate of 10 ℃ / min, the crystallization temperature from 118.38 ° C to 124.53 ℃ increase of 6.15 ° C, the nucleating agent is added in the crystallization to high temperature offset, and the crystallization speed accelerated. The nucleating agent can significantly improve the transparency and transmittance of the polypropylene. When the 0.3% polypropylene haze is reduced by 58%. 4 investigated the the lactam nucleating agent with rosin salts into the the nucleating agent complex pairing polypropylene mechanics and crystalline properties of impact. The results showed that, after a nucleating agent in the complex may be as small amplitude to improve the impact strength and transparency of the polypropylene.

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