Effects of Inorganic Elements Spray on the Content of Polyphenols in Eucommia ulmoides Olive Leaves北大核心CSCD

The effect of three kinds of microelement fertilizers spray, such as iron, zinc and manganese, on the biomass of Eucommia ulmoides Olive leaves and the contents of total polyphenols, flavonoids and chlorogenic acid(CA) in leaves were studied. Quadratic saturation D-optimization design was used to carry out the foliage spray. The equation of fertilizer effect of Fe, Zn, and Mn were established by stepwise regression method, and optimized by frequency analysis method. The result showed that the effects of Fe, Zn, and Mn on E. ulmoides leaves were not linear accumulation of individual effects. There were interactions between the factors. During the fertilization process, interaction effects should be considered synthetically to find the balance point of fertilizer application. The suitable fertilizer application for leaves of E. ulmoides were FeSO4•5H2O 0.20 % - 0.22 %, ZnSO4•7H2O 0.17 % - 0.21 % and MnSO4•5H2O 0.18 % - 0.21 %. Under the condition of Fe 0.21 %, Zn 0.19 % and Mn 0.20 %, the biomass of leaves was 220 g each, content of total polyphenol was 6.212 %, content of flavones was 3.611 % and content of chlorogenic acid was 1.918 %, which was significantly better than the control group. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Synthesis of Rosin Based Crosslinking Agent and Its Effect on Properties of Cured Silicone Rubber北大核心CSCD

Rosin modified aminopropyltriethoxysilane(RA) was obtained via rosin derivatization reaction. RA was used as crosslinking agent to prepare rosin based room temperature vulcanized silicone rubber and to study its effect on the morphology, mechanical and thermal properties of rubber. It was found that rosin based silicone rubber had better mechanical and thermal properties than those of the traditional silicone rubber. The tensile strength and elongation at break of rosin based silicone rubber were 0.51 MPa and 353% respectively, under the conditions of 11.1 g RA and 30 g hydroxyl terminated polydimethylsiloxane as primary polymers. Compared with the traditional silicone rubber, tensile strength and elongation at break of rosin increased by 11% and 84%, meanwhile the maximum weight loss rate temperature was 592 ℃, rising by 201 ℃. Correspondingly, the residual rate at 800 ℃ increased by 4.17% and the glass transition temperature of the silicone rubber also increased slightly. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Molecular Structure and Curing Characteristics of Lignin-phenol-formaldehyde Resin Prepared with the Use of Magnesian Ion as Catalyst北大核心CSCD

The narometer magnesium oxide (MgO) was used as catalysis for the preparation of lignin-phenol-formaldehyde (MLPF) resin. MgO was added in the initial stage of resin reaction. The molecular structure and thermal behavior of the curing reaction of MLPF resin were characterized by Fourier transform infrare spectroscopic (FT-IR), 13C nuclear magnetic resonance (13C NMR) and different scanning calorimetry (DSC), respectively. A comparisons to phenol-formaldehyde (PF) resin and lignin-phenol-formaldehyde(LPF) resin without adding MgO were also carried out to investigate the effects of Mg2+ on the structure and curing characteristics of MLPF resin. The research results indicated that Mg2+ could promote the formation of hydroxymethyl group, increase the amounts of methylene, restrict the formation of ether bond bridge during MLPF resin synthesis, and lead to the higher structure condensation degree of MLPF resin than that of LPF resin. MgO seemed to make MLPF resin cure faster and decrease its curing reaction temperature. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Effects of Different Hardeners on the Working Properties and Bonding Strength of Urea-formaldehyde Adhesives

The addition of a hardener is necessary for the curing of urea-formaldehyde (UF) adhesives in the production of MDF and particleboard. The most commonly used hardener, ammonium chloride, however, is suspected to cause the formation of poisonous dioxin when waste boards are combusted and hence considered as a potential source of pollution. To assess the feasibility of substituting ammonium sulphate for ammonium chloride, working properties and bonding strength were measured for UF adhesives with the two hardeners at different levels of concentration. It was found that the effects of the two hardeners are practically identical on the pH, gelation time and viscosity and bonding strength, all other conditions being the same. Both ammonium chloride and ammonium sulphate can be easily handled in the same way, and therefore there is no need to modify the application method and equipment. The practical and economical implications of these findings suggests that ammonium sulphate is an appropriate alternative to     

Synthesis and Properties of Fumaropimaric Acid Modified RTV Silicone Rubber北大核心CSCD

Fumaropimaric acid modified aminopropyltriethoxysilane(FA) was prepared by derivative reaction with rosin as raw material and the structure of the product was confirmed by FT-IR, 1H NMR and 13C NMR. Fumaropimaric acid modified room temperature vulcanized(RTV)silicone rubber was prepared by the dealcoholization condensation reaction of crosslinking agent(FA) and hydroxyl end-blocked dimethylsiloxane(PDMS). And the effects of hydrogenated phenanthrene ring of rosin on the morphology, mechanical and thermal properties of fumaropimaric acid modified RTV silicone rubber were studied, it was found that fumaropimaric acid modified RTV silicone rubber had better the mechanical and thermal properties compared to the unmodified silicone rubber. The tensile strength and elongation at break were 1.22 MPa and 315%; and The 10% mass loss temperature increased to 472 ℃ (SRFA-1), the greatest rate of mass loss temperature increased to 569 ℃, and the residual rate was 3.88%, respectively. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Process Conditions and Performance of Polyacrylate-based Super Absorbent Resin Prepared with Lignin-related Compounds北大核心CSCD

Lignin including alkali lignin (AL), lignosulfonate (LS), lignocresol (LC), lignoresorcinol (LR) and lignopyrogallol (LP) were grafted by acrylic acid (AA) to synthesized water-absorbent resin under aqueous solution with potassium persulfate (KPS) as initiator and N,N'-methylene-bis-acrylamide (MBA) as crosslinking agent. The morphological characteristic water-absorbing capacity and salt tolerance of different resins were compared. The effects of different lignins on the pore structure and specific surface area were studied. The swelling behaviors of the resins were fitted by the swelling kinetics model. The results indicated that the water absorption capacities of resins were according to the order of lignopyrogallol grafted polyacrylic acid resin(LP-g-PAA, 2 137 g/g) >lignosulfonate grafted polyacrylic acid resin (LS-g-PAA, 1 348 g/g) >lignoresorcinol grafted polyacrylic acid resin (LR-g-PAA, 1 344 g/g)>lignocresol grafted polyacrylic acid resin (LC-g-PAA, 1 262 g/g) > Alkaline lignin grafted polyacrylic acid resin (AL-g-PAA, 518 g/g)>polyacrylic acid resin (PAA, 439 g/g). The FE-SEM and BET specific surface area analyses showed that the addition of different lignins could change the pore structure and specific surface area to different degree, shich would affect the absorption. And the swelling behaviors of the resins were proved to according with Schott swelling kinetics model(R2>0.98). Salt tolerance of LP-PAA resin were affected by the valence of ion,radius of hydrated ion and concentration of ion and the results were as follows: KCl>KNO3≈LiCl>K2SO4> K2CO3> CaCl2>FeCl3. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Synthesis Mechanism of Tris(2-hydroxyethyl)isocyanate Modified Melamine Formaldehyde Impregnated Resin北大核心CSCD

The tris(2-hydroxyethyl)isocyanate(THEIC) modified melamine formaldehyde(MFT) impregnated resin was prepared with THEIC, melamine(M) and formaldehyde(F) as raw materials. The MFT resin could achieve the requirements of GB/T 14732-2006. The stability of MFT resin was significantly improved with THEIC, as the n(THEIC)/n(F) was 10 % or 15 %. MFT resin(n(F)/n(M) =1.85 and n(THEIC)/n(F)=15 %) remained highly transparent up to 24 days, and its free formaldehyde was only 0.05 %. Infrared characterization of MFT resin analysis showed that the absorption peaks of carbonyl functional groups of MFT resin changed to 1680.9 cm-1 from 1670.7 cm-1 in THEIC. The C〖FY=,*2〗N absorption peak in melamine ring was 1525.7 cm-1, and split up into two peaks(1545.3 and 1504.0 cm-1) in MFT resin. 13C NMR qualitative and quantitative analysis the reaction process of the MFT resin showed that the hydroxymethyl of amino in melamine was the main reaction and accompanied with the etherification reaction (between hydroxymethyl, hydroxymethyl and THEIC). The main reaction products were oligomers. The joining of the THEIC made the reverse reaction of the condensation of amino and hydroxyl groups, which was hydrolysis reaction,and proved that the resin storage period increased. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Effect of Pretreatment Methods on Cellulase Adsorption Profiles of Sugarcane Bagasse北大核心CSCD

The effects of two pretreatment methods, sulfite (SPORL) pretreatment and dilute sulfuric acid (DA) pretreatment, on the enzymatic hydrolysis of sugarcane bagasse (SCB) substrates were investigated and the adsorption of cellulose on SCB during the hydrolysis was studied. The enzymatic hydrolysis efficiency, composition, surface morphology, adsorption isotherms and kinetics of two kinds of pretreated SCB were compared. The results showed that the enzymatic hydrolysis efficiency of SPORL-SCB(81.92%) was significantly higher than that of DA treated SCB(60.89 %). Compared with the untreated SCB, the surface of SCB treated by SPORL and DA became rough, the surface fibres were partially stripped and the internal fibre skeleton was exposed. The holocellulose contents of these two treated SCB substrates were not significantly different, but the Klason lignin content of SPORL treated SCB was lower. The XPS images suggested that the treated SCB substrates both adsorbed cellulase. The adsorption isotherm and kinetics curves showed that the maximum adsorption of cellulase on SPORL treated SCB was 61.91 mg/g and lower than that on DA treated SCB(82.69 mg/g), but the adsorption affinity and adsorption strength of SPORL treated SCB were higher than those of the DA treated SCB. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Preparation of Rosin-based N-Heterocyclic Carbene Catalyst and Its Catalytic Properties for Addition Reaction of Aryl北大核心CSCD

Two kinds of rosin-based N-heterocyclic carbene (NHC) from dehydroabietylamine and acrypimaric amine were designed and synthesized, and their structures were identified by FT-IR, 1H NMR, 13C NMR, MS and elemental analysis. For screening the catalysts and evaluating their activity, the novel rosin-based NHC molecules were used to catalyze the addition reaction of aromatic aldehydes and aryl boronic acids. The results showed that catalytic activity of the acrypimaric-based NHC(Ap-NHC) was better than that of dehydroabietic-based NHC(Da-NHC), and the optimal catalytic effect was presented at reaction conditions of reaction temperature 60 ℃, the reaction time 4 h, the amount of catalyst 2.5 % and potassium tert-butoxide as alkali, and the yield reached to 95 %. Finally, the influence of different substituent groups on the reactant was studied. When the aryl boronic acid reacted with the aromatic aldehyde with electron withdrawing group, the yield was the highest, while the substituent on the boric acid had little effect on the reaction. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Comparation on UV curing reactivity of Allyl abietate and allyl isopimarate北大核心CSCD

The UV curing reaction of the difference between allyl abietate(AA) and allyl isopimarate(AI) was studied. The conversion rate of the vinyl double bond was characterized and detected by FT-IR analysis. Results showed that conversion of double bonds are firstly increased then decreased with the increases of the dosage of initiators. Conversion of double bonds firstly increased and then leveling off with the increases of the illumination time, and AA is higher before the 200 s. AA is higher then AI under the same illumination intensity. Surface drying time of AA is shorter than AI, and relative curing speed become faster at the same conditions. Under the conditions of 2-hydroxy-2-methylpropiophenone(Darocure-1173)as photo initiator and dosage 6%, illumination time 200 s, illumination distance 4.5 cm and illumination intensity 100%, number average molecular weight of cure products of AA and AI are 4 176 and 9 407 with polymerisation degrees of 12 and 28, respectively. The obtained UV cured coating all have smooth and transparent appearance. It represented some superior properties in flexibility, mechanical impact strength, adhesive power, hardness, acid resistance, alkali resistance, salt resistance, water resistance, etc.. The hardness of AA and AI cured products are H and HB, respectively.     

Effect of Wood Variables on the Properties of Wood Fiber-Polypropylene Composites

The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypropylene, but the tensile and unnotched charpy impact strength decreased. And the above strength decreased with the wood fiber content increasing. When the wood fiber size becoming smaller (in higher mesh), the strength increased. In the comparison of wood species, the properties of composite using Chinese fir wood were better than that of Poplar, but not significant. The dynamic mechanical properties of the composites and PP were also tested and analyzed in this paper.     

Synthesis and Antibacterial Activity of Derivatives of Rhein北大核心CSCD

Based on carboxyl amidation of rhein(1), a series of derivatives of rhein were synthesized by structure modification of C7 of anthraquinone mother nucleus. And the antibacterial activity and structure-activity relationship of the derivatives were preliminary discussed. The derivatives of rhein were respectively rhein piperidine amide(2), 7-hydroxymethyl-rhein piperidine amide(3), 7-bromomethyl-rhein piperidine amide(4), 7-(4-morpholino)methyl-rhein piperidine amide(5a), 7-(pyrrolidin-1-yl)methyl-rhein piperidine amide(5b), 7-(1-methyl-4-piperazinyl)methyl-rhein piperidine amide(5c). The structures of the compounds were characterized by IR, 1H NMR, 13C NMR, MS. The minimal inhibitory concentrations (MIC) of the compounds obtained were tested and the MIC of compounds 5a and 5b against E.coli reached 0.78 and 0.39 mg/L respectively. Their antibacterial activity were stronger than that of rhein(MIC 3.13 mg/L) obviously, even stronger than that of the kanamycin(MIC 1.56 mg/L); and the MIC of compound 5a against S. aureus reached 1.56 mg/L, which was similar to that of rhein. The preliminary analysis of structure effective relationship showed that if none replace heterocyclic groups were introduced into substituent of C7 of the mother nucleus, the antibaterial activity on E.coli would be stronger. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Regulating Effect of P-factor on Lignin Mass Concentration in Prehydrolysis Liquor of Triploid Poplar北大核心CSCD

In order to regulate the lignin mass concentration in prehydrolysis liquor, the mass concentrations of Klason lignin and acid-soluble lignin in the prehydrolysis liquor of triploid poplar were studied at different P-factor. The results showed that there was a regulating effect of P-factor on lignin mass concentration in poplar prehydrolysis liquor. The increasing processes of the mass concentration of two kinds of lignins were both divided into a fast phase (P-factor <1 200) and a following slow phase (P-factor >1 200). The mass concentration ratio of Klason lignin to acid-soluble lignin(r) was revealed at (0.50±0.03). The prehydrolysis lignin in the form of lignin-carbohydrate complex was found at P-factor <306. Klason lignin fragmentation and pseudo lignin formation were obviously indicated at P-factor>691. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Preparation of 1,8-p-Menthane Diacetamide from p-Menthadienes北大核心CSCD

Using p-menthadienes and acetonitrile as raw materials, 1,8-p-menthane diacetamide was prepared in sulfuric acid solution via Ritter reaction. The effects of the mass fraction of sulfuric acid solution, the molar ratio of p-menthadienes to sulfuric acid solution and acetonitrile, reaction temperature, reaction time and the type of p-menthadienes on the yield of 1,8-p-menthane diacetamide were optimized. The results showed that when c(H2SO4)=60%, n(H2SO4):n(p-menthadienes)= 2.2:1, n(acetonitrile):n(p-menthadienes)=2.4:1, T= 55 ℃, t=6 h, the yield of 1,8-p-methane diacetamide is the highest. Among different pure component compounds in p-menthadienes, limonene is the most efficient starting material and got the highest yiled of 61.6%. The structure of the product was identified and characterized by FI-IR,ESI+-MS and 1H NMR. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Influence of Metallic Elements Exuded from Wood Based Fly Ash on Treatment of TMP Effluent北大核心CSCD

In the process of thermomechanical pulping(TMP) effluent treatment using wood based fly ash (FA) as reactant, inorganic metallic ions can exude into the effluent from FA complex. In order to determine the metallic elements in FA would flocculate and remove the organics in the effluent under the alkaline condition, the removal behaviors of organic material were investigated by means of simulation with different kind of metallic ions addition at various dosage levels and adjusting pH value of TMP effluent, respectively. It concluded that the metallic ions combined with organics precipitate simultaneously under the alkaline condition by charge neutralization and H-bond to form large particles. The removal rates increased with the increment dosage of Mg2+ and Fe3+, while the Ca2+ and Al3+ would not be affected by their dosage under the alkaline condition. When the pH values were 10 and 12, respectively, the removal capability of Ca2+ and Mg2+ was maximum at pH value 12, while Al3+ achieved peak removal rate at pH 10. The removal efficiency from Fe3+ kept constant between pH value 10 and 12. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Promotion of in situ enzymatic degradation on natural plant fiber by ionic liquid北大核心CSCD

An ionic liquid, i.e., 1-ethyl-3-methylimidazolium ([EMIM]OAc), was used to treat two natural plant fiber (Salix psammophila and cotton). The effects of this pretreatment on the enzymatic degradation of these two materials were investigated in present study. The optimum condition for degradation was obtained as 3.64 mL pH 5 citric acid-sodium citrate buffer solution was added to 5g 4% natural plant fiber[EMIM]OAc solution. A reaction system with 55 g/L fiber substrate was obtained. The optimal ratio of enzyme to substrate was 0.5 ∶1(mL ∶g), and the optimal reaction temperature and reaction time were 55℃ and 25 h, respectively. Under the optimal condition, the enzymatic degradation of the two natural plant fiber was beyond 90%. The FT-IR showed that the hydrogen bondings of fiber were broken by [EMIM]OAc in the process of dissolution. It resulted in a fiber material with more amorphous pattern. These changes would increase the accessibility between fiber and cellulase. This led to more enzymatic degradation of cellulose.     

Effect of Wood Particle Size on the Properties of Wood/Polypropylene Composites Ⅰ:Mechanical Properties

The mechanical properties of wood powder/polypropy!ene composites with different wood particle sizes and wood species have been studied. All of the wood particie sizes increased the E-modulus of the composites. Tensile tests showed that wood partide sizes had a negative effect on the elongation at break and the tensile strength of the composites has been improved when wood particle sizes were be(ow 150 μm (below 100 mesh). For the impact tests, the wood partide sizes had a negative effect, but the MDF fiber can increase the Izod impac     

Research Advances on Glycoside Hydrolases with Two Catalytic Domains北大核心CSCD

This review presented the reaserch progresses in the natural domains analysis, artificial construction, modification, and application of glycoside hydrolases with two catalytic domains. The study of glycoside hydrolases with two catalytic domains on improving thermostability and catalytic activity were highlighted. In addition, the catalytic mechanism of glycoside hydrolases with two catalytic domains was explored, and also the research directions of glycoside hydrolases with two catalytic domains were prospected. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Thermal Decomposition Characteristics and Kinetics of Tea Stalk北大核心CSCD

In order to provide comprehensive utilization of tea stalk waste by thermochemical conversion, the thermal decomposition process of tea stalk and its kinetics were studied with simultaneous measurements of thermogravimetry (TG)/differential thermal analysis (DTA). The TG-DTG-DTA curves of tea stalk were acquired in a nitrogen atmosphere. The results indicated that the mass loss process of the samples could be divided into five stages. Among the five stages, most of the decomposition occurred in the third and fourth stages. The two main stages were indicated as exothermic processes, with the average weight loss rates of 55.12% and 28.48% at different heating rates of 10, 15, 20, 25 K/min, respectively. At higher heating rate, the fourth stage of the decomposition reaction was shifted to higher temperature range. The thermal decomposition kinetic parameters were calculated by Kissinger, FWO peak maximum evolution and FWO isoconversional methods. The results showed that the Kissinger and FWO peak maximum evolution methods were more suitable for the thermal decomposition kinetic parameters. The apparent activation energies were calculated to be 666.53 and 642.80 kJ/mol by the two methods, respectively. And natural logarithm of the pre-exponential factor (lnA) calculated by Kissinger method was given as 145.83. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Ultrasonic-assisted Radical Process for Directed Degradation of Arabinogalactan北大核心CSCD

Arabinogalactan (AG) was extracted from the sawdust of larch (Larix gmelinii(Rupr.) Kuzen). The arabinogalactan obtained was physically degraded by ultrasound-assisted free radicals. The free radical scavenging ability of decomposed AG was selected as an indicator on the evaluation of the antioxidant activity. On the basis of single-factor test, response surface optimization was used to determine the optimal degradation conditions, and the optimum conditions are found as follows: the dpolysaccharide concentration was 10 g/L; ultrasonic temperature was 60℃; the H2O2 volume fraction was 6%; and the ultrasonic time was 60 min. Under this optimum degradation condition, the ·OH scavenging rate of arabinogalactan was 89.6%, and Mr of AG was degraded from 52 ku to around 25 ku, and the cumulative weight fraction of this molecular weight reached 60%.Compared with AG, the antioxidant activity of arabinogalactan oligosaccharide(AG-O) obtained in the anti-oxidative activity was significantly enhanced, and its IC50 value decreased from 2.058 g/L to 0.497g/L. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.