New insight into the action of supercritical carbon dioxide for grafting of maleic anhydride onto isotactic polypropylene by reactive extrusion

Cao, Kun; Shen, Zhicheng; Yao, Zhen; Qu, Bang-Wei; Pang, Xi-bin; Lu, Zhan-Quan; Li, Yan; Chen, Zhenhua

doi:10.1016/j.ces.2009.11.004

Cited by 34 publications

(12 citation statements)

References 13 publications

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“…Initially, PP has to be functionalized with maleic anhydride to form maleated PP ( Scheme 1 a). This step has been intensively investigated and numerous reports are available in open literature [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Thus, the synthesis of polypropylene graft maleic anhydride (PpgMA) is outside the scope of this work and we decided to use commercially available PpgMA as the starting material.…”

Section: Introductionmentioning

confidence: 99%

Cross-Linking of Polypropylene via the Diels–Alder Reaction

et al. 2022

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In this work, the possibility of preparing cross-linked polypropylene (PP) via Diels–Alder (DA) chemistry is explored. The overall strategy involves reaction of maleated polypropylene (the starting material), furfuryl amine (FFA), and bismaleimide (BM) as the cross-linking agent. The occurrence of reversible cross-linking was studied by checking the presence of relevant peaks in FTIR spectra, i.e., CH out-of-plane bending vibrations of the furan ring’s peak (γCH) at an absorption band of 730–734 cm−1, CH=CH of the BM aromatic ring’s stretching vibrations (υCH=CH) at an absorption band of 1510 cm−1, and the DA adduct (C-O-C, δDAring) at an absorption band of 1186 cm−1. In agreement with the spectroscopic characterization, the presence of a cross-linked network is also confirmed by rheology, namely the higher storage modulus (G′) compared with loss modulus (G″) value (G′ >> G″), as obtained via temperature sweep. Both the maleic anhydride (MA) content as well as the annealing temperature (50 °C and 120 °C) favor the DA reaction, while only partial de-cross-linking (retro DA) is observed at the higher temperature range of 150–200 °C. In addition, the products show higher mechanical robustness and thermal stability compared to the starting material.

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Section: Introductionmentioning

confidence: 99%

Cross-Linking of Polypropylene via the Diels–Alder Reaction

et al. 2022

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“…The aim of this work is to investigate the application of TMA and API as a novel precursor in the synthesis of cross-linked PP. In this work, we limit our research scope by using commercially available maleated PP since the synthesis of this material has been extensively explored and reported in open literature [ 30 , 31 , 32 , 33 ]. The reaction proceeds via grafting of TMA or API onto maleated PP and follows with the DA reaction between pendant thiophene and BM (see Scheme 1 a), while for API, the imidazole pendant cross-linked reaction with BM can proceed via DA or Michael addition ( Scheme 1 b,c).…”

Section: Introductionmentioning

confidence: 99%

Cross-Linking of Polypropylene with Thiophene and Imidazole

et al. 2022

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In this work, two novel routes to synthesis cross-linked polypropylene (PP) are introduced by using two different precursors (2-thiophenemethyl amine (TMA) and 1-(3 aminopropyl) imidazole (API)), both cross-linked with 1,1′-(methylenedi-4,1-phenylene) bismaleimide (BM) at two different annealing temperature values (T = 50 °C and T = 150 °C). Both Diels–Alder (DA) and Michael addition reactions were successfully performed with TMA and API, respectively, albeit with different reactivity. Imidazole clearly shows a higher reactivity compared to thiophene. In addition, an increase in annealing temperature leads to a higher degree of cross-linking. The highest degree of cross-linking was obtained by the imidazole product after annealing at 150 °C (IMG1A150) as evident from the highest complex viscosity (|η*|) value of IMG1A150. A difference in rheology and thermal properties between the imidazole and thiophene cross-linked products was also observed. However, both products have superior melt properties and thermal stability compared with the starting material. They show processability at high temperatures. The melt flow behavior and de-cross-linking at higher temperatures can be tuned depending on the choice of imidazole or thiophene. This study shows an advance on the cross-linked PP processing and its product performances for further application on the commercial scale.

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“…To date the iPP modification by LCBs is a two-step process: i) functional group (predominantly maleic anhydride MAH) introduction onto the linear iPP chains and ii) reaction coupling of MAH with complementary functional groups such as amine. Building upon our previous work on these two individual processes, 15–17 In this work a “one-pot” iPP modification via reactive extrusion was investigated, where MAH grafting and coupling reactions proceeded concurrently. Such a process should increase the efficiency and reduce the cost in producing long chain branched iPP (LCB-PP).…”

Section: Introductionmentioning

confidence: 99%

Influence of molecular structure on the rheological properties and foamability of long chain branched polypropylene by “one-pot” reactive extrusion

Yao

Qiu

et al. 2020

Journal of Cellular Plastics

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In this work, reactive twin screw extrusion was conducted to synthesize long chain branched polypropylenes (LCB-PPs) in a “one-pot” process in which dicumyl peroxide (DCP) initiated maleic anhydride (MAH) grafting onto the linear PP, and the concomitant coupling reaction between ethylene diamine (EDA) and MAH grafted polypropylene (PP-g-MAH) proceeded in series. Fourier transfer infrared spectroscopy (FTIR) on the prepared materials confirmed the occurrence of both reactions. A series of LCB-PPs were prepared using different amounts of EDA, MAH and DCP to study their effects and determine the optimal synthesis conditions. The prepared materials were characterized by size exclusion chromatography (SEC) and rheological analysis to ascertain the polymer microstructure. The foamability of the LCB-PPs by supercritical carbon dioxide (scCO2) foaming and foam morphology were investigated. The LCB-PPs were found to have vastly improved foamability and cellular morphology. Under optimal conditions, a foam expansion ratio of over 20 was achieved.

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New insight into the action of supercritical carbon dioxide for grafting of maleic anhydride onto isotactic polypropylene by reactive extrusion

Cited by 34 publications

References 13 publications

Cross-Linking of Polypropylene via the Diels–Alder Reaction

Cross-Linking of Polypropylene via the Diels–Alder Reaction

Cross-Linking of Polypropylene with Thiophene and Imidazole

Influence of molecular structure on the rheological properties and foamability of long chain branched polypropylene by “one-pot” reactive extrusion

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