Reinforcement of polypropylene by cellulose microfibers modified with polydopamine and octadecylamine

Abstract

Cellulose microfibers (CMFs) having surfaces modified with polydopamine (PDPA) and octadecylamine (ODA) were prepared, and their reinforcing abilities for polypropylene (PP) were investigated. The PDPA coating was made via self‐polymerization of dopamine (P‐CMF), and subsequent alkylation was conducted by the reaction with ODA (OP‐CMF). The modified CMFs exhibited improved dispersibility in the PP matrix due to the reduced hydrophilicity. The OP‐CMF/PP composite prepared by batch mixing had a higher tensile modulus compared to that for the pure PP and composites with unmodified CMFs. However, excess alkylation lowered the tensile modulus, and the presence of an optimal degree of alkylation was demonstrated. The CMF/PP‐IM composites fabricated by injection molding exhibited improved tensile properties compared to those prepared by batch mixing. Both the tensile modulus and yield stress were increased by increasing the CMF content and improved by the surface modification of the CMFs.

Preparation of BTCA‐esterified cellulose nanocrystals and effects on mechanical and thermal properties of polypropylene composites

“…The composites' damping peak suggested that once a material has been deformed, it would not return to its previous shape. With the addition of esterified CNC, the peak amplitude increased by 1.7°C at high temperature, indicating a higher degree of molecular mobility 34 . The esterified CNC in the composites may have improved its interaction with the PP matrix, which could have been the explanation.…”

Study on water absorption of hydrophobically modified ramie fiber and the reinforced polypropylene composites

“…Unexpectedly, with the increase of ODA concentration, the excessive coating may reduce the roughness of the surface of fiber, thus inhibiting the entanglement between fiber and the polypropylene molecular chains. In addition, excessive ODA could be regarded as an “interface lubricant,” which made the tensile strength and tensile modulus of the composites tend to decrease, and the elongation at break gradually increase 38 …”

“…The P-RF was further modified by introducing octadecyl chains via Michael addition of the catechol group with the amino group of ODA. 38 In addition, during PDA formation, DA (covering on fiber) could be oxidized into chinone, providing the carbonyl groups for reacting with NH 2 on ODA by the Schiff base reaction. 39 ODA was dissolved in ethanol to a concentration of 0.5/1/2/4/8 g/L.…”

In-vial solid-phase extraction of polycyclic aromatic hydrocarbons in drug formulations stored in packaging containing rubber

“…Clearly, there is a compromise of the recovery between low-ring and high-ring PAHs. [51][52][53] Considering the recoveries of all 16 PAHs within an acceptable range, 0.25 mg mL −1 ODA was selected for further optimization. Next, we investigated the effect of reaction time on the recoveries of PAHs as the time was varied from 0.5 h to 4 h. As shown in Fig.…”