The effect of hyperbranched polymer lubricant as a compatibilizer on the structure and properties of lignin/polypropylene composites

Abstract

In this work, the lignin/polypropylene (PP) composites were prepared by lignin and PP using hyperbranched polymer lubricant (HBPL) as a compatibilizer, which was synthesized by oleic acid and amino-terminated hyperbranch (HBP-NH₂) polymer in toluene solvent. The impact and flexural strength of the resulting composites were investigated. Experimental results indicated that the impact strength and flexural strength of lignin/PP composites modified with HBPL are 52.3% and 63.6% higher than that of untreated systems, respectively. HBPL treatment could also significantly improve the melt flow rate (MFR) of the lignin/PP composites. Meanwhile, the storage modulus (E′) of adding the HBPL was slightly higher than that of the uncompatibilized system. In addition, scanning electron microscope images showed that the dispersion of the lignin added with HBPL in the polymer matrix was improved. It can be inferred that the lignin and PP matrix interfacial bonding was strengthened.

Keywords:

• Hyperbranched polymer lubricant
• lignin
• polypropylene
• composites

Acknowledgements

The authors are grateful for the financial support by the National Natural Science Foundation of China (Nos. 51163004 and 51163003), the Scientific Research and Technology Development Plan of Guangxi Province of China (Nos. 1298025-8 and 0992022-4) and Innovation Team of Guangxi Universities' Talent Highland.