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A simple, green, and efficient mechanical activation-assisted esterification (MAE) technology was developed for the preparation of cellulose acetate butyrate (CAB), which was used as film-former for pearlescent coating. In addition, CAB was also prepared by a traditional liquid phase esterification (LPE) method for comparing the structures and characteristics of the CABs prepared by these two technologies. 1H and 13C NMR confirmed that CAB was successfully produced, and the degree of substitution of acetyl and butyryl groups was also calculated. The crystal structure and molar mass of the CABs prepared by MAE and LPE methods were dissimilar, ascribing to different reaction systems and characteristics. FTIR, SEM, and transparency analyses were used to investigate the chemical structure and surface characteristics of CAB films, and appearance, glossiness, rub resistance, and ethanol resistance measurements were carried out to investigate the surface and wear characteristics of CAB/pearlescent coating films. The results indicated that the surface and wear characteristics of the films based on MAE- and LPE-prepared CABs were similar to the same reaction time, and the interfacial adhesion and compatibility among components significantly affected the characteristics of the films.

Lignin was treated by mechanical activation (MA) in a customized stirring ball mill, and the structure and reactivity in further esterification were studied. The chemical structure and morphology of MA-treated lignin and the esterified products were analyzed by chemical analysis combined with UV/vis spectrometer, FTIR,NMR, SEM and particle size analyzer. The results showed that MA contributed to the increase of aliphatic hydroxyl, phenolic hydroxyl, carbonyl and carboxyl groups but the decrease of methoxyl groups. Moreover, MA led to the decrease of particle size and the increase of specific surface area and roughness of surface in lignin. The reactivity of lignin was enhanced significantly for the increase of hydroxyl content and the improvement of mass transfer in chemical reaction caused by the changes of molecular structure and morphological structure. The process of MA is green and simple, and is an effective method for enhancing the reactivity of lignin.

Cellulose succinate, which was used for efficient adsorption of heavy metals, was directly prepared by mechanical activation (MA)-assisted solid-phase synthesis in a stirring ball mill with bagasse pulp and succinic acid as materials without the use of organic co-reagents and solvents. FTIR, XRD, SEM, and specific surface area analysis were used to characterize the structural characteristics of cellulose succinate. Furthermore, the effects of different degrees of esterification of modified cellulose on the adsorption of Cd2+ and Pb2+ were investigated. A surface charge characteristic was used to prove the effect of pH on the adsorption ability of cellulose succinate. It was found that the adsorption kinetics of Cd2+ and Pb2+ onto cellulose succinate fitted well with the pseudo-second-order model. The adsorption of Cd2+ and Pb2+ onto cellulose succinate was well described by the monolayer adsorption of the Langmuir isotherm model rather than the multilayer adsorption of the Freundlich isotherm model. The E values for the adsorption of Cd2+ and Pb2+ by cellulose succinate calculated by the Dubinin–Radushkevich equation were all in the range of 8–16 kJ mol−1, suggesting that the adsorption process mainly proceeded by ion exchange. The MA-assisted solid-phase synthesis method can produce efficient and environmental-friendly adsorbents.

This study investigated the direct production of octenyl succinic anhydride modified starch (OSA-starch) by a non-conventional mechanical activation (MA)-assisted solid phase synthesis (MASPS) technology without the use of solvents and additives in a stirring ball mill. FTIR analysis confirmed that the OSA-starches with different degrees of substitution (DS) had been successfully produced by MASPS with different MA time, ascribing to the changes in structure and physicochemical properties induced by intense mechanical actions. XRD and SEM analyses showed that the crystal structure and morphology of starch were significantly disrupted after the process of MASPS. The OSA esterification of starch by MASPS resulted in the increase of cold-water solubility, transparency, and emulsion stabilization, and the reduction of paste viscosity and retrogradation, and these changes were enhanced with the increase of MA time. It indicated that the OSA-starch prepared by MASPS possessed some unusual functional properties, which can be favorable for special applications.

Esterification is an important chemical modification for the preparation of natural cellulose-based materials. However, esterification of cellulose is commonly carried out in organic solvents, which reduces the economic and environmental feasibility of the synthetic technologies. Herein we report a novel technology for the production of cellulose esters, which combines mechanical activation (MA) and esterification in a stirring ball mill under solid phase conditions without the use of solvents. With the use of acetic anhydride as co-reactant and fatty acids as long chain esterifying agents, 1H and 13C NMR measurements confirmed that both acetyl and long chain fatty acyl groups were successfully grafted on cellulose by the technology of MA-assisted solid phase synthesis (MASPS). The factors which contributed to the successful preparation of cellulose esters were: the formation of highly reactive mixed acetic-long chain fatty acid anhydride, the generation of active hydroxyl groups in cellulose, the weakening of the steric effect of long chain fatty acids, and the improved contact between reagents and cellulose which were first induced by intense milling. It also showed that the reactivity of fatty acids and the degree of substitution (DS) of fatty acyls decreased with the increase in their chain length, and the long chain fatty acylium ions preferred to react with the more reactive hydroxyl group in the anhydro glucose unit of cellulose. Moreover, Fourier transform infrared spectroscopy, X-ray diffractometry, and scanning electron microscopy analyses were used to measure the changes in chemical structure, crystal structure, and surface morphology of the cellulose before and after esterification by MASPS, respectively. The results indicate that this green, simple, and efficient technology is suitable for the direct production of cellulose esters with long chain substituents.

Cassava stillage residue (CSR), a kind of agro-industrial plant fibres, was directly acetylated and converted into thermoplastic material by mechanical activation-assisted solid phase reaction (MASPR) in a stirring ball mill without the use of organic solvent and additives. As combining mechanical activation and chemical modification in the same equipment, the destruction of hydrogen bonds and crystalline structure of CSR induced by intense milling improved the reactivity of CSR, leading to the effective acetylation of CSR. After acetylation by MASPR, the modified CSRs possessed thermoplasticity, ascribing to the introduction of acetyl groups and the destruction of high crystallinity structure of cellulose. The self-reinforced all-plant fibre composites (APFC) were successfully produced with the modified CSRs as both matrix and reinforcement by hot pressing technology. The direct acetylation of CSR and successful production of APFC suggested that MASPR was a simple, efficient and environmentally friendly method for chemical modification of agro-industrial lignocellulose biomass.

A kind of natural cellulose, bleached pine pulp (BPP), was pretreated by mechanical activation (MA) using a self-designed stirring ball milling. The effect of MA pretreatment on the dissolving capacity and molecular chain structure of BPP were investigated by the determination of alkaline solubility (Sa) and degree of polymerization (DP). In addition, the changes in crystal structure of MA-pretreated BPP with different milling times were qualitatively and quantitatively measured by X-ray diffraction and Fourier transform infrared spectroscopy, and the morphology modification was observed by scanning electron microscopy. It was found that MA significantly increased the Sa and reduced the DP of BPP, contributing to the destruction of inter- and intramolecular hydrogen bonds and macromolecular chains in cellulose. The stable crystal structure of BPP was also remarkably damaged during MA processing, resulting in the variation of surface morphology, the increase of amorphous region ratio and hydrogen bond energy, and the decrease in crystallinity and crystalline size, which efficiently increased the accessibility of natural cellulose and would have positive effects on subsequent treatments. The crystalline form of natural cellulose was not changed by MA, and no new functional groups generated during milling.

The chemical modification of lignin can greatly enhance its functionality and exploit its application areas. To avoid the difficulties of separation and environmental pollution in the traditional liquid-phase method, we prepared acetylated lignin by a mechanical-activation-assisted solid-phase synthesis (MASPS) technology with a customized stirring ball mill as a reactor and studied its structure and properties. Ultraviolet–visible analysis showed that the degree of esterification (DE) of the acetylated lignin produced by the MASPS technique was 77.59%, whereas the DEs of those produced by traditional liquid-phase synthesis (LPS) and thermal solid-phase synthesis (TSPS) were only 42.29 and 27.54%, respectively. Fourier transform infrared spectroscopy and NMR analyses indicated that both phenolic hydroxyls and aliphatic hydroxyls participated in the reaction, and the reactivity of the phenolic hydroxyls was higher than that of the aliphatic hydroxyl groups. The acetylation of aliphatic hydroxyl mainly happened at the γ of arylglycerol-β-aryl ether (β-O-4). Scanning electron microscopy analysis showed that the acetylated lignins prepared by MASPS and TSPS were irregular blocks with coarse surfaces and loose structures, whereas the lignin prepared by LPS consisted mostly of regular balls with a smooth surface and a compact structure. Differential scanning calorimetry and thermogravimetric analyses indicated that the glass-transition temperatures and thermal stability of the acetylated lignin increased by orders with the processing techniques of MASPS, TSPS, and LPS. MASPS integrated the activation and reaction in the same equipment without the use of a solvent and showed advantages of a high efficiency, environmental protection, and easy operation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44276.