Introductory Chapter: Polypropylene - Synthesis and Functionalization

Wang, Weiyu

doi:10.5772/intechopen.92067

Cited by 3 publications

(3 citation statements)

References 26 publications

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“…The synthesis of PP from propene by chain-growth polymerization ( Figure 8 ) has been known since the 1950s and was initially studied by Hogan and Banks. The potential applications of PP show a dependence on mechanical properties and thermal resistance that were improved by relevant advances of Natta and Ziegler, who developed a stereospecific polymerization using organometallic catalysts arising isotactic PP [ 78 ]. Considering that PP is a cheap polymer with excellent processability, chemical resistance, and moisture barriers, the chemical development favored the global industrial production of PP, which was 50 Mt in 1976 and grew to 360 Mt in 2018 [ 79 ].…”

Section: Nude Electrospun Nanofibersmentioning

confidence: 99%

“…However, the synthesis and functionalization of PP is an interesting current study area, where the obtention of novel polymers with different tacticity allow for potential applications in textile, automotive, cosmetics, and consumer packaging. In this sense, the polydispersity and molecular weight are controlled using transition metal (N,N-dietil hafnio) and metal alkyl chain transfer agent as ZnEt 2 to produce amorphous atactic polypropylene (a-PP) with narrow polydispersity and molecular weights of 12.6 kDa to 111 kDa [ 78 ]. Moreover, PP shows interesting and convenient mechanical properties as polyethylene–polypropylene blends and polypropylene nanocomposite fibers [ 79 , 80 ].…”

Section: Nude Electrospun Nanofibersmentioning

confidence: 99%

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Nude and Modified Electrospun Nanofibers, Application to Air Purification

et al. 2023

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Air transports several pollutants, including particulate matter (PM), which can produce cardiovascular and respiratory diseases. Thus, it is a challenge to control pollutant emissions before releasing them to the environment. Until now, filtration has been the most efficient processes for removing PM. Therefore, the electrospinning procedure has been applied to obtain membranes with a high filtration efficiency and low pressure drop. This review addressed the synthesis of polymers that are used for fabricating high-performance membranes by electrospinning to remove air pollutants. Then, the most influential parameters to produce electrospun membranes are indicated. The main results show that electrospun membranes are an excellent alternative to having air filters due to the versatility of the process, the capacity for controlling the fiber diameter, porosity, high filtration efficiency and low-pressure drop.

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Section: Nude Electrospun Nanofibersmentioning

confidence: 99%

Section: Nude Electrospun Nanofibersmentioning

confidence: 99%

Nude and Modified Electrospun Nanofibers, Application to Air Purification

et al. 2023

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“…Since the discovery of the Ziegler–Natta catalyst more than 60 years ago, the consumption of polyolefins has been growing with catalyst technology and polymerization process innovations [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. In 2021, the global consumption of polyolefins had arrived at approximately 200 million tons, and polypropylene (PP), typically isotacitc PP, is widely used in various walks of life, such as automobiles, packaging, household, medical and facilities industries [ 8 , 9 ], with predicted global demand of above 75 million tons in 2022.…”

Section: Introductionmentioning

confidence: 99%

Porous Organic Polymers-Supported Zeigler-Natta Catalysts for Preparing Highly Isotactic Polypropylene with Broad Molecular Weight Distribution

Wang

Xue-mei

et al. 2023

Polymers

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Porous organic polymers (POPs) have attracted much attention in numerous areas, including catalysis, adsorption and separation. Herein, POP supported Ziegler–Natta catalysts were designed for preparation of isotactic polypropylene (iPP). The POPs-based Ziegler–Natta catalysts exhibited the characteristic of broad molecular weight distribution (MWD > 11) with or without adding an extra internal electron donor. The added internal electron donor 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate (ID-2) used in cat-2 showed good propylene polymerization activity of 15.3 × 106 g·PP/mol·Ti·h, high stereoregularity with 98.2% of isotacticity index and broad molecular weight distribution (MWD) of 12.3. Compared to the MgCl2-supported Ziegler–Natta catalysts (cat-4) with the same ID-2, cat-2 showed higher chain stereoregularity for propylene polymerization. As seen in the TREF results, the elution peak of PP-2 (124.0 °C, 91.7%) is 1.5 °C higher than the isotactic fraction from PP-4 (122.5 °C, 87.2%), and even 1.2 °C higher than PP-5 prepared from ID-3 with the characteristics of high stereoregularity. Moreover, the pentad methyl sequence mmmm of PP-2 (93.0%) from cat-2 is 0.5% higher than that of PP-4 from cat-4. XPS analysis revealed that the minute difference in binding energy of Ti, Mg, C and O atoms exist between the inorganic MgCl2 and the organic polymer based Z–N catalysts. The plausible interaction mechanism of active sites of Mg and Ti with the functional groups in the POP support and the added ID was proposed, which could be explained by their high stereoregularity and the broad molecular weight distribution of the POP-based Z–N catalysts.

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