Effect of Graft Molecular Weight and Density on the Mechanical Properties of Polystyrene-Grafted Cellulose Nanocrystal Films

2021 ◽  
Author(s):  
James H. Lettow ◽  
Han Yang ◽  
Paul F. Nealey ◽  
Stuart J. Rowan
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cellulose Nanocrystal ◽  
Nanocrystal Films

scholarly journals Effects of Polymer Additives and Dispersion State on the Mechanical Properties of Cellulose Nanocrystal Films

2017 ◽  
Vol 302 (4) ◽  
pp. 1600351 ◽  
Author(s):  
Joshua M. Passantino ◽  
Alexander D. Haywood ◽  
Joyanta Goswami ◽  
Virginia A. Davis
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanocrystal ◽  
Polymer Additives ◽  
Dispersion State ◽  
Nanocrystal Films

scholarly journals Effect of A Limited Amount of D-Sorbitol on Pitch and Mechanical Properties of Cellulose Nanocrystal Films

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1324
Author(s):  
Xiao-Yao Wei ◽  
Tao Lin ◽  
Le Wang ◽  
Xue-Feng Yin
Keyword(s):  
Mechanical Properties ◽  
Self Assembly ◽  
Aqueous Suspension ◽  
Young Modulus ◽  
Cellulose Nanocrystal ◽  
Chiral Structure ◽  
Liquid Crystal Films ◽  
Significant Difference ◽  
Crystal Films ◽  
Nanocrystal Films

A cellulose nanocrystal (CNC) suspension can form liquid crystal films with unique self-assembly behaviors. This gives CNC films a special iridescence, which has potential in many aspects, but the brittleness of pure CNC films limits their application. In this work, we propose a simple physical mixing method to obtain CNC film by adding D-sorbitol as a plasticizer. We first found that low D-sorbitol content (less than 6 wt% in CNC/DS composite solution) did not make a significant difference compared with pure CNC films in optical performance and, at the same time, the mechanical properties of the CNC films were improved. The various low contents of D-sorbitol can be well dispersed in CNC aqueous suspension, and the wavelength of the selectively reflected phenomenon is relatively stable and slightly decreased at 5 nm for concentrations from 0 to 6%. This phenomenon is opposite to that generally reported, where the wavelength of the selective reflected phenomenon increases obviously with the increase in plastic content. The pitch of the chiral structure decreased from 406 to 362 nm with an increase in D-sorbitol concentration. When the content of D-sorbitol reached 4%, the tensile strength, elongation at break, and Young modulus increased to 39.9 Mpa, 3.00%, and 2.99 GPa, respectively.

scholarly journals Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Nur Sharmila Sharip ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Yoshito Andou ◽  
Yuki Shirosaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Yield Strength ◽  
Young’S Modulus ◽  
High Molecular Weight ◽  
Melt Processing ◽  
Cellulose Nanofiber ◽  
Melt Blending ◽  
Ultra High Molecular Weight

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.

scholarly journals Improving Rheological and Mechanical Properties of Various Virgin and Recycled Polypropylenes by Blending with Long-Chain Branched Polypropylene

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1137
Author(s):  
Sascha Stanic ◽  
Thomas Koch ◽  
Klaus Schmid ◽  
Simone Knaus ◽  
Vasiliki-Maria Archodoulaki
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Test ◽  
Reactive Extrusion ◽  
Original Material ◽  
Melt Flow Rate ◽  
Single Screw Extruder ◽  
Pp Blends ◽  
The Impact ◽  
Long Chain

Blends of two long-chain branched polypropylenes (LCB-PP) and five linear polypropylenes (L-PP) were prepared in a single screw extruder at 240 °C. The two LCB-PPs were self-created via reactive extrusion at 180 °C by using dimyristyl peroxydicarbonate (PODIC C126) and dilauroyl peroxide (LP) as peroxides. For blending two virgin and three recycled PPs like coffee caps, yoghurt cups and buckets with different melt flow rate (MFR) values were used. The influence of using blends was assessed by investigating the rheological (dynamic and extensional rheology) and mechanical properties (tensile test and impact tensile test). The dynamic rheology indicated that the molecular weight as well as the molecular weight distribution could be increased or broadened. Also the melt strength behavior could be improved by using the two peroxide modified LCB-PP blends on the basis of PODIC C126 or PEROXAN LP (dilauroyl peroxide). In addition, the mechanical properties were consistently enhanced or at least kept constant compared to the original material. In particular, the impact tensile strength but also the elongation at break could be increased considerably. This study showed that the blending of LCB-PP can increase the investigated properties and represents a promising option, especially when using recycled PP, which demonstrates a real “up-cycling” process.

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