Physicochemical and Mechanical Properties of Polypropylene-cellulose Nanocrystal Nanocomposites: Effects of Manufacturing Process and Chemical Grafting

Abstract

Chemical modifications have been widely adopted for improving the dispersibility of cellulose nanocrystals (CNCs) in nonpolar matrixes. Nonetheless, an engineering design for improving the CNC structure is still challenging due to the differences in the dispersion level of CNCs depending on the modification strategies in a desired matrix. The current study was conducted to find an appropriate functionalization technique for CNCs and an effective manufacturing process for CNC-polypropylene (PP) nanocomposites. The surface structures of CNCs were successfully changed using toluene diisocyanate (TDI) and maleic anhydride grafted PP (MAPP). The tensile properties and thermal stability of the nanocomposites with MAPP grafted CNCs were higher than those of pristine and TDI grafted CNC systems. A melt-extrusion process with predispersion processing exhibited more positive effects on the properties of the nanocomposites in comparison to the systems without pre-dispersion. Scanning and transmission electron microscopes also provided clear evidence of the dispersion levels of unmodified and modified CNCs in the PP matrix.

Recent advances in compatibilization strategies of wood-polymer composites by isocyanates

“…Moreover, such a coupling agent system resulted in a significant decrease in water uptake, which can be considered beneficial because it retards the degradation of biocomposites. Table 3 Enhancement of composites' mechanical performance after modification of pineapple leaf fiber with 5 wt% of pMDI (George et al 1996(George et al , 1997 Gwon et al (2018) grafted TDI onto the surface of cellulose nanocrystals (CNCs) to reduce their polarity and enhance the dispersibility in the hydrophobic polypropylene matrix. Then, the suspension of modified CNCs in acetone was added to hot toluene, and powdered PP was introduced.…”

Preparation and Characteristics of Cellulose Acetate Based Nanocomposites Reinforced with Cellulose Nanocrystals (CNCs)

“…나노셀룰로오스의 한 종류인 셀룰로오스 나노크리스탈은 직경 5-70nm, 길이 100nm-수 마이크로 크기의 결정형 나노셀룰로오스이다. CNC 나노입자는 낮은 밀도(1.6 gcm -3 ), 높은 비표면적(300m 2 g -1 )을 가지고 있을 뿐 아니라 높은 인장강도(7.5-7.7 GPa)와 탄성(143 GPa)을 보인다 (Gwon et al, 2018;Majoinen et al, 2011;Ljungberg et al, 2006;Moon et al, 2011). 이러한 CNCs의 특징은 연구자들로 하여금 고분자 복합소재의 강도 향상을 위한 강화제(reinforcement)로써 사용하기에 충분한 매력을 가지고 있다 (Jo et al, 2015;Masruchin et al, 2015;Park et al, 2016) (Leite et al, 2016).…”

“…TEC, a plasticizer added to improve the efficiency of the melting process was set to 30 wt.% of the total weight. To effectively disperse the CNC nanoparticles between the CA main chains, a predispersion method using solvents was applied to the process (Gwon et al, 2018). When nanocomposites are fabricated through the melting process, the viscosity of the polymer is high at the molten state of the polymer, and therefore, the nanoparticles do not sufficiently disperse in the matrix, and an aggregation occurs so that the function of the nanoparticles as a reinforcing agent is difficult to carry out.…”

“…) and shows high tensile strength (7.5-7.7 GPa) and elasticity (143 GPa) (Gwon et al , 2018;Majoinen et al, 2011;Ljungberg et al, 2006;Moon et al, 2011). These features of CNCs are good enough for researchers to use as a reinforcing agent to increase the strength of polymer composite materials (Jo et al, 2015;Masruchin et al, 2015;Park et al, 2016).…”

Cumulative energy and cost demand analysis in the synthesis of antistatic bionanocomposites compared with the synthesis of polypropylene

“…The antistatic bionanocomposites could be synthesized using mono-diacylglycerols (M-DAG) as an antistatic agent [1], cellulose nanocrystals (CNC) as a reinforcement [2][3][4], polypropylene (PP) as a thermoplastic matrix [2,3], and supporting materials consists of maleic anhydride polypropylene (MAPP), antioxidant (AO), dan mineral oil (MO) [2][3][4][5][6][7]. The synthesis of antistatic bionanocomposites (AS BNC) requires energy and costs from energy and material usage [8].…”