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The combination of crystallization, transparency, and strength is still a challenge for broadening the application of polylactic acid (PLA) films, while it is also difficult to balance. In this work, the long aliphatic chains of octadecylamine (ODA) were grafted onto the surface of cellulose nanocrystal (CNC) by tannic acid oxidation self-polymerization and Michael addition/Schiff base reaction between polytannic acid and ODA. Furthermore, the ODA grafted CNC (g-CNC) was used as green reinforcement for the PLA matrix and a series of PLA/g-CNC nanocomposite films were prepared by the casting method. The DSC, WAXD, POM, UV-vis and stretching test were employed to examine the effect of g-CNC on the properties of the as-prepared PLA/g-CNC nanocomposite films. It shows that the g-CNC is effective to improve the melt crystallization rate of PLA from 11 min to 7.3 min. Most importantly, the crystal size of the PLA spherulites was significantly reduced due to the well dispersion in the amorphous PLA matrix, which would effectively improve the transmittance of the PLA films and synchronously realize the combination of crystallization (62 %) and transparency (80.6 %). Moreover, the improved crystallization could also enhance the heat deformation performance of the PLA films since the heat resistance is closely associated with the crystallinity. Besides, the grafted ODA long chains improve the compatibility between CNC and PLA, leading to the reinforcement of PLA matrix, where the tensile strength reaches 65.05 MPa from 44.31 MPa. Compared with the pristine CNC, the addition of g-CNC makes more comprehensive improvement in the properties of the PLA films., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this research, nanocellulose crystal (NCC) grafted with lactic acid (LA) oligomer was synthesized by one-pot method and used to reinforce the poly(l-lactic acid) (PLLA) matrix. FT-IR, XRD, and 13 C NMR were used to analyze the structure of modified nanocellulose crystal (g-NCC). The results of GPC suggested that the degree of polymerization of the grafted segments was 23, and the degree of hydroxyl substitution of g-NCC was 2.4%. For the g-NCC/PLLA composite, its crystallization rate increases significantly compared with pure PLLA, indicating that g-NCC acted as a nucleating agent to promote the crystallization. Moreover, tensile strength of the composite materials was significantly improved from 41.9 MPa to 53.9 MPa due to the enhanced compatibility. This study provides a fast and effective modification method for g-NCC/PLLA biodegradable composites. According to the above-mentioned experimental results, the g-NCC/PLLA composites can be considered as a potential material in the packaging field, mainly due to its proper biological and physicochemical properties., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, composite membranes were prepared from mixed solution of polyvinylidene fluoride (PVDF) and cellulose via the non-solvent-induced phase separation (NIPS) method. N, N-dimethylacetamide (DMAc) and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) were used as the solvent for PVDF and cellulose, respectively. SEM and in situ scanning techniques were used to investigate the morphology of the prepared membranes. The results showed that viscose cellulose/[Bmim]Cl solution acted as a porogenic agent during the membrane preparation process. Hydrophilicity of the composites was evaluated by water contact angle, moisture regain and equilibrium water uptake, which demonstrated that the wettability of the membranes was associated with the hydrophilic group and the roughness of the surface. Most importantly, the α → β transformation in PVDF matrix was demonstrated from the results of WAXD, FT-IR and DSC. The quantitative analysis indicated that the β-phase content in PVDF reached 90.1% when cellulose content was 5%, which is higher than many published references and was ascribed to the cooperation of cellulose and ionic liquid. Besides, the crystallinity, thermal stability and mechanical properties of the composite membranes were studied as well. [ABSTRACT FROM AUTHOR]

ABSTRACT In the present study, regenerated cellulose membrane with 'imprinted morphology' and low crystallinity was fabricated from the crystal cellulose/[Bmim]Cl solution. Spherulites of 1-butyl-3-methilimidazolium chloride ([Bmim]Cl) and cellulose/[Bmim]Cl solution were observed using polarized optical microscopy under certain condition. The fabricated cellulose membranes presented some particular characteristics compared with the membrane prepared from traditional cellulose/[Bmim]Cl solution. All the fabricated membranes were characterized by optical microscope, Wide-angle X-ray diffraction (WAXD), thermo-gravimetric analysis, and mechanical testing. The images showed that the resulting membranes prepared from crystal cellulose/[Bmim]Cl solution were 'imprinted' with patterns which originated from the crystalline structure of [Bmim]Cl. The results of WAXD showed that the obtained cellulose membrane exhibited low diffraction peaks and crystallinity of approximately 24.57%. Furthermore, the low crystallinity led to the low mechanical property (27.5 MPa), thermal stability (315.4 °C), and high moisture regain (9.5%). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43798. [ABSTRACT FROM AUTHOR]

Inthis paper, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was synthesizedand used as solvent to dissolve bamboo pulp. Dimethylsulfoxide (DMSO)was selected as cosolvent to adjust the solution viscosity. As comparedwith the bamboo pulp/[Bmim]Cl system, the addition of DMSO decreasesthe solution viscosity dramatically. Afterward, cellulose hollow fibermembranes were prepared by dry-wet spinning process using 75 wt %[Bmim]Cl + 25 wt % DMSO as solvent. Scanning electron microscope (SEM),mechanical testing, pure water permeability, and retention rate wereused to characterize its properties, respectively. The SEM resultshows that the prepared cellulose hollow fiber membrane presents densesurface structure, which leads to a relative high tensile strengthand retention rate to bovine serum albumin, i.e. 28 MPa and 98%, respectively,but a relative low pure water permeability, i.e. 83 L/m2·h. In the end, the [Bmim]Cl is recovered by azeotropy, andthe recycling yield reaches 99 wt %. [ABSTRACT FROM AUTHOR]

Abstract: A binary system consisting of acidic ionic liquid glycine hydrochloride (Gly·HCl) and neutral ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) is proposed to be cosolvent for chitosan and cellulose, the spinning solution of chitosan/cellulose can be prepared in one step. The regenerated chitosan/cellulose composite fiber with 9.4wt.% chitosan was prepared through dry–wet spinning process. SEM shows that the chitosan is scattered on the surface and interior of the composite fiber. WAXD shows that the degree crystallization of the composite fibers is far less than that of raw materials. The result of elemental analysis (EA) indicates that there is little weight loss of chitosan during the spinning process. Moreover, the prepared composite fiber presents good thermal stability, i.e. its T onset is 305.1°C, and excellent mechanical property, i.e. its tensile strength is 4.63cN/dtex. All the results show that Gly·HCl/[Bmim]Cl binary system is a promising solvent for the preparation of chitosan/cellulose composite fiber. [Copyright &y& Elsevier]

The aim of this paper is the preparation and characterization of cellulosechitin blend filaments over the experimental blend ratio scope i.e., 2.89 and 6.46 ww chitin content through high wet modulus HWM procedure. The spinnability of the invested solutions was found to vary in the following order: chitin < cellulose < 9.5:0.5 blend < 9:1 blend < 8:2 blend < 5:5 blend 9:1 means the mass ratio of cellulose to chitin, so does 9.5:0.5, 8:2, and 5:5. The crosssection of the blend filaments is of chrysanthemum shape. It was shown through the SEM photographs that there existed grooves on the surface of filaments, which became coarse with increase in chitin content. Based on the data from Xray, sonic velocity, intensity, and hygroscopicity, it is concluded that the degree of crystallinity, dry and wet intensity modulus, degree of orientation, and regain rate of the filaments decreased with increase in chitin content in the experiment scope. The mechanical properties of the blend filaments are much higher than those of Crabyon fiber and normal viscose filaments, which proves that the HWM method is an efficient way of preparing cellulosechitin blend filaments with satisfactory mechanical properties and processing property. The blend filaments prepared have an effective biostatic effect on Staphylococcus aureus, Escherchia coli, and Corinebaterium michiganenceaccording to different testing standards. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article discusses a study on the preparation and characterization of cellulose/chitin blend filaments obtained from cellulose/chitin xanthalate blend solution over an experimental blend ratio. The study showed that chitin xanthalate addition into cellulose xanthalate resulted in an increase of intermittence rate. It also concluded that the degree of crystallinity, density and accessibility of blend filaments decreases with increasing chitin content.

This paper investigated the feasibility of enhancing the interface between lignocellulosic fibers and a polypropylene matrix via structure alteration of lignin at elevated temperatures. Alkali treatment can remove gum substances from lignocellulose fibers effectively at elevated temperatures but easily causes damages to fiber strength. In previous studies on directional delignification of lignocellulosic fibers, loss of fiber strength is avoided but condensation and degradation of lignin are accelerated. So far, few reports have been available on the effect of lignin structures on the interface between fibers and a matrix. In this study, jute fibers with different lignin structures are produced at 100 and 130 °C for reinforcing a polypropylene matrix. The interface between the fibers and matrix is analyzed. The result shows that decrease in aliphatic hydroxyl concentration by 9.5% at 130 °C from 3 to 5 h contributes to a 14.2% decrease in the surface energy of jute fibers. Meanwhile, the polydispersity index of lignin decreases from 1.21 to 1.15. Centralized distribution of lignin molecule-weight and reduction in fiber surface energy improves the interface between the fibers and matrix, which manifests as a 30.8% increase in the impact strength of the composites. Similar improvement is not observed in the composites reinforced with jute fibers at 100 °C, due to the absence of lignin-structure changes. This paper provides a new strategy to improve the interface between lignocellulose fibers and a hydrophobic matrix. [ABSTRACT FROM AUTHOR]