Surface modification for nano‐lignocellulose fiber through vapor‐phase‐assisted surface polymerization

This study addresses the inherent issues surrounding surface modification methods of nanofibers and proposes an environmentally friendly and less toxic strategy for the surface modification of hydrophilic nanofiber. From the continuation of our previous work, which discussed the easy production of nanofiber (average size: 127 nm) from oil palm mesocarp fiber (OPMF), in this work, the surface of nanofibers (M‐IL‐OPMF) were modified through vapor‐phase‐assisted surface polymerization (VASP) to improve the affinity of interface between the polymer grafted M‐IL‐OPMF and non‐polar matrix. VASP of ε‐caprolactone was successfully proceeded from the [M‐IL‐OPMF] at 70 °C for 24 h and 72 h, and compositions were estimated to be 35.7% fiber/64.3% polymer and 27.8% fiber/72.2% polymer. To confirm the grafting of PCL, size‐exclusion chromatography (SEC) and Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetry (TG), and dispersibility test in hydrophobic solvent were carried out. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2575–2580     

Morphological,thermal, and biodegradation properties of LLDPE/treated date palm waste composite buried in a soil environment

In this study, date palm waste that was naturally treated as a filler in a linear-low density polyethylene (LLDPE) matrix was recycled to prepare green composites. Two types of LLDPE, based on basic additives, were used. UV stabilizer and the slip and anti-block were added as basic additives. The objective of this study was to examine the effect of these basic additives and the treated filler on the biodegradation, morphological, and thermal properties of the prepared samples by a soil burial test. The samples were characterized by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Weight loss was calculated to investigate the biodegradation of the sample, and SEM and thermogravimetric analyses were performed to reveal the morphology and thermal properties before and after burial, respectively. Results showed that the presence of the bio-filler accelerated the biodegradation of the composites. The UV stabilizer had a positive impact on biodegradation factors whereas anti-block additives appeared resistant to biodegradable factors. The morphology and thermal stability of all the prepared samples changed after burial due to the effects of biodegradation during the burial.     

The Effect of Alkaline Addition in Hydrothermal Pretreatment of Empty Fruit Bunches on Enzymatic Hydrolysis Efficiencies

In general, lignocellulosic biomass contains three major components, namely lignin, hemicellulose and cellulose which are the polymers of C5 and C6 sugars. Thus, there is potential to utilize of this biomass for bioethanol production. The hydrolysis of cellulose into glucose was difficult due to the more fibrous nature and thus inhibit enzyme penetration into the cellulose. In order to solve this problem, hydrothermal pretreatment can be used for breaking the bonds within the lignin structure and increase the accessibility of enzyme into the cellulose. In this study, the effect of chemical addition, sodium hydroxide (NaOH) and calcium oxide (CaO) in hydrothermal pretreatment at 180 °C and 30 minutes reaction time of palm oil empty fruit bunches (EFB) on the enzymatic hydrolysis efficiencies was investigated. The enzymatic hydrolysis of hydrothermally pretreated EFB give the highest concentration of glucose at 0.67 g/L while the hydrothermally pretreated of EFB in the presence of NaOH gives the lowest glucose concentration 0.45 g/L.     

Improved synthesis of P(3HB-co-3HV-co-3HHx) terpolymers by mutant Cupriavidus necator using the PHA synthase gene of Chromobacterium sp. USM2 with high affinity towards 3HV

Unlike polyhydroxyalkanoates (PHAs) copolymers, the controlled and efficient synthesis of PHA terpolymers from triglycerides and fatty acids are yet to be established. This study demonstrates the production of P(3HB-co-3HV-co-3HHx) terpolymer with a wide range of 3HV monomer compositions from mixtures of crude palm kernel oil and 3HV precursors using a mutant Cupriavidus necator PHB⁻4 transformant harboring the PHA synthase gene (phaC) of a locally isolated Chromobacterium sp. USM2. The PHA synthase of Chromobacterium has an unusually high affinity towards 3HV monomer. P(3HB-co-3HV-co-3HHx) terpolymers with 3HV monomer composition ranging from 2 to 91 mol% were produced. Generation of 3HHx monomers was affected by the concentration and feeding time of 3HV precursor. P(3HB-co-24 mol% 3HV-co-7 mol% 3HHx) exhibited mechanical properties similar to that of common low-density polyethylene. P(3HB-co-3HV-co-3HHx) terpolymers with a wide range of 3HV molar fraction had been successfully synthesized by adding lower concentrations of 3HV precursors and using a PHA synthase with high affinity towards 3HV monomer.     

Biosynthesis and characterization of novel polyhydroxyalkanoate polymers with high elastic property by Cupriavidus necator PHB4 transformant

We attempted to synthesize novel polyhydroxyalkanoate (PHA) containing new 3-hydroxy-4-methylvalerate (3H4MV) monomer from the transformed strain of Cupriavidus necator PHB⁻4 harboring the PHA synthase gene of Chromobacterium sp. USM2 (phaC_Cs). Novel PHA containing SCL and MCL monomers were successfully synthesized from crude palm kernel oil (CPKO) and isocaproic acid. Results showed that P(3HB-co-1 mol% 3HV-co-3 mol% 3H4MV-co-18 mol% 3HHx) possessed higher thermal stability, higher elastomeric behavior at room temperature and higher ductility than the P(3HB-co-5 mol% 3HHx). The novel PHA film was found to possess an interesting rubber-like elasticity and flexibility property which has not been reported. The soil surface degradation study showed that the novel PHA film was degraded faster than the 3HB homopolymer and copolymer with 5 mol% of 3HHx.     

Evaluation of a novel metal–organic framework as an adsorbent for the extraction of multiclass pesticides from coconut palm (Cocos nucifera L.): An analytical approach using matrix solid‐phase dispersion and liquid chromatography

We report the synthesis, characterization, and application of [Zn(1,4‐benzenedicarboxylate)(H₂O)₂]_n , Zn(1,4‐benzenedicarboxylate)_0.99(NH₂‐1,4‐benzenedicarboxylate)_0.01(H₂O)₂]_n , [Zn(1,4‐benzenedicarboxylate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n as sorbents for the extraction of multiclass pesticides from coconut palm. Liquid chromatography with ultraviolet diode array detection was used as the analysis technique, and the experiments were performed at one fortification level (0.1 μg/g). The recoveries were 47–67, 51–70, 58–72, and 64–76% for [Zn(1,4‐benzenedicarboxylate)(H₂O)₂]_n , Zn(1,4‐benzenedicarboxylate)_0.99(NH₂‐1,4‐benzenedicarboxylate)_0.01(H₂O)₂]_n , [Zn(1,4‐benzenedicarboxylate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenelate)_0.95(NH₂‐1,4‐benzenedicarboxylate)_0.05(H₂O)₂]_n , and [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n , respectively, with relative standard deviation ranging from 1 to 7% (n = 3). Detection and quantification limits were 0.01–0.05 and 0.05–0.2 μg/g, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.01–10.0 μg/g) with r ² > 0.9991. A direct comparison of [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n with the commercially available neutral alumina showed that [Zn(1,4‐benzenedicarboxylate)_0.9(NH₂‐1,4‐benzenedicarboxylate)_0.1(H₂O)₂]_n was a similar extracting phase for the pesticides investigated.     

Deciphering key proteins of oil palm (Elaeis guineensis Jacq.) fruit mesocarp development by proteomics and chemometrics

Palm oil is an edible vegetable oil derived from lipid‐rich fleshy mesocarp tissue of oil palm (Elaeis guineensis Jacq.) fruit and is of global economic and nutritional relevance. While the understanding of oil biosynthesis in plants is improving, the fundamentals of oil biosynthesis in oil palm still require further investigations. To gain insight into the systemic mechanisms that govern oil synthesis during oil palm fruit ripening, the proteomics approach combining gel‐based electrophoresis and mass spectrometry was used to profile protein changes and classify the patterns of protein accumulation during these complex physiological processes. Protein profiles from different stages of fruit ripening at 10, 12, 14, 15, 16, 18 and 20 weeks after anthesis (WAA) were analysed by two‐dimensional gel electrophoresis (2DE). The proteome data were then visualised using a multivariate statistical analysis of principal component analysis (PCA) to get an overview of the proteome changes during the development of oil palm mesocarp. A total of 68 differentially expressed protein spots were successfully identified by matrix‐assisted laser desorption/ionisation‐time of flight (MALDI‐TOF/TOF) and functionally classified using ontology analysis. Proteins related to lipid production, energy, secondary metabolites and amino acid metabolism are the most significantly changed proteins during fruit development representing potential candidates for oil yield improvement endeavors. Data are available via ProteomeXchange with identifier PXD009579. This study provides important proteome information for protein regulation during oil palm fruit ripening and oil synthesis.     

Metabolites identification of oil palm roots infected with Ganoderma boninense using GC–MS-based metabolomics

An approach to metabolomics profiling of non-infected and Ganoderma boninense (G. boninsense) infected oil palm roots crude extracts that utilize gas chromatography-mass spectrometry (GC–MS) and multivariate statistics of principal component analysis (PCA) have been tested. This combination has provided a rapid approach in investigating the changes in the metabolite variations of non-infected and infected oil palm roots at 14 and 30 days post-infection. The extracts were prepared by using 80% (v/v) of methanol. In identifying the metabolites responsible for each differentiation, PCA model was generated in loading bi-plot. Dimethyl benzene-1,4-dicarboxylate, methyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate, ergost-5-en-3-ol, (3β), stigmast-5-en-3-ol, (3β), stigmasterol, methyl hexadecanoate, methyl (9Z,12Z)-octadeca-9,12-dienoate, methyl octadecanoate, 2-(hydroxymethyl)-2-nitropropane-1,3-diol, methyl (Z)-octadec-6-enoate and (E)-icos-5-ene were found more abundant in G. boninense infected roots than in non-infected roots. Steroidal compounds and fatty acid derivatives which has been determined in the non-infected and G. boninense infected roots regulate a variety of responses to the G. boninense. The abundant of these metabolites in G. boninense infected roots are due to the crucial roles in pathogen defence.     

不同酯基结构的棕榈油生物柴油的性能研究

以棕榈油为研究对象,分别与甲醇、乙醇、异丙醇和异丁醇进行酯交换反应制备了不同酯基结构的生物柴油。利用差示扫描量热仪和应力控制流变仪分析了不同酯基结构棕榈油生物柴油的结晶行为和低温流变性能,同时分析了酯基结构对生物柴油的氧化稳定性,40℃时的动力黏度、20℃时的密度等重要性质的影响。结果表明,随着醇的碳链长度的增加,棕榈油生物柴油的析蜡点和胶凝点均降低,特别是棕榈油异丁酯的析蜡点和胶凝点分别降低到了-2.57和-8.09℃,低温流动性得到了明显改善,且氧化诱导期略有延长,氧化稳定性有所改善。生物柴油的密度和黏度随着酯基结构的不同而有所变化,但其数值都符合中国生物柴油标准。     

Non-linear mechanical behaviour and bio-composite modelling of oil palm mesocarp fibres

Understanding the non-linear mechanical behaviour of oil palm mesocarp fibres (OPMF) is important for bio-composite application. The mechanical characterisation of this fibre is challenging due to the microstructure of the fibres consisting of silica bodies on the surface and cellular structures within the cross section. In this work, we proposed a constitutive material model for OPMF by including a stress-softening function into the large strain viscoelastic model. The model shows agreement with loading–unloading and stress relaxation tensile tests. The model was then used for micro-scale finite element modelling of the fibre–silica body–matrix (resin) interface to simulate sliding of a bio-composite material. A multi-particles model was also developed to check the effect of the constitutive model towards the mechanics of a bio-composite system. Modelling results suggested that under the micro-scale level (~50 μm), silica body plays a major role in improving the mechanical behaviour of the bio-composite system. On the other hand, under the macro-scale level (~0.18 mm), a single fibre model is sufficient to simulate a bio-composite multi-fibres material.