Effect of chain⁃branched structure on properties of polypropylene with broad molecular weight distribution based on twin⁃screw reactive extrusion

doi:10.19491/j.issn.1001-9278.2025.02.002

Abstract

Abstract:

The polypropylene （PP） with a broad molecular weight distribution was used as a matrix for preparing long⁃branched chain PP due to its excellent mechanical properties and processability. The twin⁃screw reactive extrusion was carried out to prepare the long branched⁃chain PP， enhancing the production efficiency. Additionally， melt radical grafting was conducted at two different temperature. The effect of long chain⁃branched structure on the properties of PP was investigated by using gel permeation chromatography， Fourier⁃transform infrared spectroscopy， and rheometry to determine the molecular weight and distribution， grafting degree， and tensile rheological behavior of the of the as⁃prepared PP. The mechanical test results indicated that the mechanical properties of the as⁃prepared PP decreased with an increase in the reaction temperature； however， its mechanical strength increased slightly with an increase in the content of long branched chains. The thermal analysis demonstrated that there was a significant increase in the crystallization temperature of PP but a decrease in its degree of crystallinity with an increase in the content of long branched chains. The crystallization temperature was increased by 11 ℃ at a processing temperature of 200 ℃ and a monomer content of 4 wt% compared to pure PP.

Key words: broad molecular weight distribution, polypropylene, twin?screw, reaction extrusion, long branched chain

CLC Number:

TQ325.1⁺4

XU Wei, LYU Mingfu, DU Wenjie, GUO Peng, XU Yaohui. Effect of chain⁃branched structure on properties of polypropylene with broad molecular weight distribution based on twin⁃screw reactive extrusion[J]. China Plastics, 2025, 39(2): 6-11.

Figures/Tables 16

References 14

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样品	抗氧剂1010/%	DMDBH	PETA
E02ES	0.3	0	0
E⁃S⁃D0	0.3	0.1	0
E⁃S⁃D2	0.3	0.1	1
E⁃S⁃D3	0.3	0.1	2
E⁃S⁃D4	0.3	0.1	4

样品	抗氧剂1010/%	DMDBH	PETA
E02ES	0.3	0	0
E⁃S⁃D0	0.3	0.1	0
E⁃S⁃D2	0.3	0.1	1
E⁃S⁃D3	0.3	0.1	2
E⁃S⁃D4	0.3	0.1	4

样品	单体接枝率
E⁃S⁃D2⁃180	0.19
E⁃S⁃D3⁃180	0.33
E⁃S⁃D4⁃180	0.57

样品	单体接枝率
E⁃S⁃D2⁃180	0.19
E⁃S⁃D3⁃180	0.33
E⁃S⁃D4⁃180	0.57

样品	单体接枝率
E⁃S⁃D2⁃200	0.25
E⁃S⁃D3⁃200	0.41
E⁃S⁃D4⁃200	0.74