Preparation of polypropylene with high melt strength by wet reaction blending of lignin

Abstract

In this paper, the melt strength of polypropylene is shown to be significantly improved by lignin‐cooperative construction of heterophase network structure and the evolution mechanism of lignin on the topology of polypropylene is investigated. Electron paramagnetic resonance (EPR) analysis shows that the free radicals generated by polypropylene irradiation can remain active for 2 weeks; rheological studies show that lignin promotes the formation of heterogeneous network structures in polypropylene, and its melt is characterized by long‐chain branching. Phase angle‐complex modulus, complex viscosity‐complex modulus, Han's, and Cole–Cole curves are used to analyze the liquid–solid transformation, and the results indicate that the enhanced interfacial action is due to the formation of the heterogeneous network structures. The mechanical properties show that the impact strength is increased by 1.8 times due to the synergistic effect of lignin and acrylamide. SEM shows the formation of a fibrous network structure around the lignin, which undergoes interfacial yielding, improving the interfacial interaction between the components.

Transparent, Self‐Adhesive, Conductive Organohydrogels with Fast Gelation from Lignin‐Based Self‐Catalytic System for Extreme Environment‐Resistant Triboelectric Nanogenerators

“…However, one limitation of lignin should not be ignored despite its remarkable catalytic effect; that is, excessive AL and the corresponding quinone intermediates would scour free radicals to inhibit intermolecular crosslinking. [26] That is why the gelation failed when the AL content in the whole gel system exceeded 0.53 wt.%. In parallel, the gelation time can be optimized from 6 min to 45 s by adjusting the water to EG ratio from 5:0 to 1:4 when 0.040 wt.% AL was employed (Figure 2C).…”

Synthesis of a hydrophobic associating polymer and its application in plugging spacer fluid

“…The polymers were able to adhere tightly to the cake surface because of the interaction between the polymers together with the interaction between the polymers and lignin. One research 32 mentioned that there is hydrogen bonding between lignin and polyacrylamide. Adding lignin to the mixture of polypropylene and polyacrylamide can significantly improve the compatibility between polypropylene and polyacrylamide.…”