黄麻PHBV复合材料的耐湿热性能研究

用非织造布技术制作了黄麻/PHBV针刺毡,热压处理后制成黄/PHBV复合材料,通过对复合材料的室温、高温干态和湿态力学性能研究,用扫描电镜(SEM)对复合材料的界面进行了表征,显示应用纤维改性技术使复合材料耐湿热性能得到明显提高.     

硅烷处理对Henequen纤维／PHBV树脂可生物降解复合材料界面粘结性能的影响

本文通过对Henequen纤维表面进行硅烷化改性，使得纤维与树脂间存在化学键合，提高了Henequen纤维与聚羟基丁酸与戍酸酯（PHBV）树脂复合材料界面剪切强度。Henequen纤维/PHBV复合材料界面剪切强度的大小用微粘结法（Microbond)测试，结果表明纤维经硅烷处理后可使界面剪切强度从未处理情况下的5.05Mpa提高6.34Mpa。     

硅烷处理对Henequen纤维/PHBV树脂可生物降解复合材料界面粘结性能的影响

本文通过对Henequen纤维表面进行硅烷化改性,使得纤维与树脂间存在化学键合,提高了Henequen纤维与聚羟基丁酸与戍酸酯(PHBV)树脂复合材料界面剪切强度.Henequen纤维/PHBV复合材料界面剪切强度的大小用微粘结法(Microbond)测试,结果表明纤维经硅烷处理后可使界面剪切强度从未处理情况下的5.05Mpa提高6.34Mpa.     

外源硒及脯氨酸对菜用黄麻生长和生理特性的影响

为明确外源硒及脯氨酸(Pro)对菜用黄麻生长和生理特性的影响,本研究以新型菜用黄麻品种福农1号为材料,测定了在水培液中添加不同浓度的硒(0、0.2、0.5、1.0、2.5、5.0 mg/L)与脯氨酸(50μmol/L)对菜用黄麻苗期生长、叶绿素、渗透调节物质及抗氧化酶活性的影响。结果表明:(1)外源硒浓度≤0.5 mg/L时,能促进菜用黄麻的株高、根长、株重及根重,而外源硒浓度≥2.5 mg/L时则会对其生长产生抑制和毒害作用;浓度为0.2 mg/L的硒最有利于菜用黄麻福农1号苗期的生长发育;硒浓度较低时,外源脯氨酸具有促进菜用黄麻生长的作用,而硒浓度较高时,脯氨酸可缓解硒对菜用黄麻生长的抑制。(2)外源硒可促进菜用黄麻中叶绿素的合成,亦能促进游离脯氨酸、可溶性糖和可溶性蛋白等渗透调节物质的形成,并且随硒浓度增加呈现先升高后降低的变化趋势;硒浓度为0.5和1.0 mg/L时,可最大程度地促进菜用黄麻叶绿素和渗透调节物质的合成;外源脯氨酸亦具有促进菜用黄麻叶绿素和渗透调节物质合成的功能,并且对高浓度硒造成的毒害有一定的缓解作用。(3)中低浓度的硒(0.5和1.0 mg/L)明显促进菜用黄麻超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)等抗氧化酶的活性,而高浓度硒(5.0 mg/L)抑制菜用黄麻抗氧化酶的活性;随外源硒浓度增加,菜用黄麻抗氧化酶活性呈先升高后降低的趋势;外源脯氨酸能促进菜用黄麻抗氧化酶的活性,硒浓度为2.5和5.0 mg/L时,添加脯氨酸的处理POD、SOD和CAT活性高于未添加者,表明脯氨酸具有增强菜用黄麻抵抗力和自由基清除的能力,从而可以缓解高浓度硒的胁迫。以上结论对菜用黄麻这一新型蔬菜的生产具有重要的理论和实践意义。     

气象条件对黄麻产量的影响

生产实验证明：气象条件是农作物产量形成的重要因素，它对黄麻产量的作用和影响，迄今尚未见有分析报导。为了认识气象条件(温度、日照、降雨量)与黄麻产量的关系，以便采取相应的技术措施，促进黄麻生产的进一步提高，我们就197l—1979年气象条件对黄麻产量的影响进行了分析。     

移栽黄麻高产结构与长势观察

黄麻育苗移栽是夺取粮麻双丰收的有效措施．为了进一步探讨黄麻育苗移栽高产技术，我们于1979-1982年在杭州市西湖区石桥公社杨家大队对移栽黄麻的经济性状，长势，笨麻消长以及高产施肥等情况进行了观察研究。     

恢复黄麻生产 开发黄麻新产品

黄庥在我国具有近千年种植历史,尽管作为传统包装材料使用正居于次要地位,但由于黄麻纤维具有优质、可降解特性,我国麻纺科技人员及企业正在开发新产品,如高支黄麻纱、布;黄麻/棉、黄麻/化纤、黄麻/羊毛、黄麻/丝等混纺高档产品,以及汽车、装饰等产业用品.许多企业正呼吁恢复我国黄麻种植,以减少对孟加拉进口黄麻的依赖.     

黄麻与棉转杯混纺纱的纺制

本文对黄麻/棉混纺纱的生产工艺作了初步的探索,利用经过脱胶后的精细化黄麻纤维,通过对纺纱加工工艺与设备的选择、调整,纺制成了黄麻/棉55/45的转杯混纺纱.结果表明,黄麻纤维在脱胶精细化处理后,是可以加工成应用领域更广泛的产品的.     

菜用黄麻资源筛选及品质评价

对30份菜用黄麻资源从生物学特性、产量、菜用品质等方面进行研究,结果表明,现蕾日数、鲜嫩茎叶产量分别高于对照种（埃及黄麻）的有14份和16份;食味性状鉴定评分评价高于或相当于对照种的有17份;钙含量高于对照种有6份;有6份硒含量达10.2ug/100g DW以上,高于菜花（硒含量7.2ug/100g DW）。综合评价较好的菜用黄麻资源是巴长4号和越南长果,建议进行示范推广。     

《苎麻讲义》和《黄麻、红麻讲义》内容简介

一九八。年，我所受农业部委托，举办了全国麻类技术干部训练班，讲授了苎麻、黄麻、红麻的基础知识，编印了《苎麻讲义》和《黄麻、红麻讲义》。这两本讲义，结合建国三十年来麻类作物的生产成就，科研成果，深入浅出的详细论述了苎麻、黄麻、红麻的植物学特征及生物学特性，     

Structure and filtration performance of fibrous composite membranes containing environmentally friendly materials for water purification

A fibrous composite membrane consisting of a chitosan (CS) barrier layer and a poly(hydroxybutyrate-cohydroxyvalerate) (PHBV) fibrous substrate was manufactured as a filter for water purification. The PHBV fibrous supporting layer was fabricated via electrospinning technique, and then the CS solution cast on the PHBV fibers to form the top barrier layer. The structural morphology, mechanical property and adsorption capability of the PHBV/CS membranes were thoroughly investigated. Three heavy metal ions were used to evaluate the equilibrium absorption capacities of the chosen membranes. The equilibrium absorption capacities for Cu(II), Pb(II) and Cd(II) were 64.08 mg/g, 90.32 mg/g and 148.96 mg/ g, respectively. Meanwhile, the rejection ratio of PHBV/CS composite membrane for two disperse dyes could reach to 99 %. The results indicated that PHBV fibrous substrate could not only enhance the mechanical strength of the top barrier layer, but also improve the water permeation of the membrane. This study extended the application of an environmentally friendly material in the water purification without causing much trouble about scrap film.     

Block copolymers containing poly (3-hydroxybutyrate-co-3-hydroxyvalerate) and poly (<Emphasis Type="Italic">ɛ</Emphasis>-caprolactone) units: Synthesis,characterization and thermal degradation

Biodegradable block copolymers containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly (ɛ-caprolactone) (PCL) units (PHCLs) with different contents of PCL block were synthesized successfully by using telechelic hydroxylated PHBV (PHBV-diol) with low molecular weight as a macroinitiator to initiate ring-opening bulk polymerization of ɛ-caprolactone (ɛ-CL). The chemical structure and molecular weight were characterized by 1H NMR, FTIR and GPC. The PHBV and PCL blocks in PHCLs were miscible in amorphous state, and formed separate crystalline phases with lower crystallinity than corresponding homopolymers, which was characterized by DSC and WAXD. The results of TGA showed that PHCLs underwent a two-step thermal degradation process. The thermal degradation process of PCL blocks was significantly different from PCL homopolymers. The activation energies of thermal degradation of PCL blocks calculated by Horowitz and Metzger method were much higher than that of each step of thermal degradation of PCL homopolymers.     

Composites of polyolefin elastomer reinforced with short carbon fiber and its copolymerization conditions

To study the effects of short carbon fiber (SCF) on the properties of the polyolefin elastomers (POEs), we prepared the poly(ethylene-co-1-hexene) (PEH)/SCF composites at different percentages of SCF. We also prepared polyethylene (PE)/SCF composites to compare with PEH/SCF composites. PEH was synthesized by the copolymerization of ethylene and 1-hexene using metallocene catalyst/cocatalyst system. Optimum stirring speed, Al/Zr feeding molar ratio, polymerization time, and polymerization temperature were 700 rpm, 600, 30 min, and 60 °C, respectively. We investigated the morphology of the composites using scanning electron microscopy (SEM) and found that the wettability of SCF in PEH/SCF composites was fairly better than that of SCF in PE/SCF composites. It was observed from mechanical tests that the ultimate tensile strength and tensile modulus of PEH/SCF composites were remarkably enhanced as the SCF content increased, whereas those of PE/SCF composites were a little increased. PEH/SCF composites exhibited lower crystallinity than PE/SCF ones. Thermal stability of the composites was enhanced by the addition of SCF.     

Hybrid effect in the mechanical properties of jute/rockwool hybrid fibres reinforced phenol formaldehyde composites

This research work was concerned with the evaluation of the effect of fibre content on the mechanical properties of composites. Composites were fabricated using jute/phenol formaldehyde (PF), rockwool/PF, and jute/rockwool hybrid PF with varying fibre loadings. Jute and rockwool fibre reinforced PF composites were fabricated with varying fibre loadings (16, 25, 34, 42, 50, and 60 vol.%). The jute/rockwool hybrid PF composites were manufactured at various ratios of jute/rockwool fibres such as 1:0, 0.92:0.08, 0.82:0.18, 0.70:0.30, 0.54:0.46, 0.28:0.72, and 0:1. Total fibre content of the hybrid composites was 42 vol.%. The results showed that tensile strength of the composite increased with increasing fibre content up to 42 vol.% over which it decreased for jute and rockwool fibre reinforced PF composites. Flexural strength of the composite was noted to peak at a fibre loading of 42 vol.% for jute/PF composites, and 34 vol.% for rockwool/PF composites. Impact strength of jute/PF composites increased with increasing fibre loading but that of rockwool/PF composites decreased at higher (>34 vol.%) fibre loadings. Tensile, flexural, and impact strengths of jute/PF composites were found to be higher than those of rockwool/PF composites. The maximum hardness values were obtained 42 vol.% for jute/PF composite, and 34 vol.% for rockwool/PF composite. Further increase in fibre loading adversely affected the hardness of both composites. For jute/rockwool hybrid PF composites, tensile and impact strengths decreased with increasing rockwool fibre loading. The maximum flexural strength of jute/rockwool hybrid PF composites was obtained at a 0.82:0.18 jute/rockwool fibre ratio while maximum hardness was observed at a 0.28:0.72 jute/rockwool fibre ratio. The fractured surfaces of the composites were analysed using scanning electron microscope in order to have an insight into the failure mechanism and fibre/matrix interface adhesion.     

Green composites from maleated castor oil and jute fibres

Castor oil was converted to maleated castor oil (MACO) without any catalyst. MACO was characterized with FTIR, NMR, molecular weight and viscosity measurement. Tung oil (20 wt%) was added to MACO as reactive diluent. Non-woven jute felts were used as reinforcing material. The MACO was polymerized and crosslinked in situ during composite fabrication. The curing behavior of MACO with free radical catalyst was investigated by differential scanning calorimetry (DSC). The MACO/jute composites were tested for their flexural properties, impact strength and dynamic mechanical properties and compared with similar unsaturated polyester resin/jute composites. The flexural moduli of both the composites were nearly similar. The impact strength of MACO/jute composites was 42% higher than that of UPE/jute composites. The damping property of the MACO/jute composites was higher than that of UPE/jute composites over a wide range of temperature.     

Characterization of plant and animal based natural fibers reinforced polypropylene composites and their comparative study

Natural fibers are largely divided into two categories depending on their origin: plant based and animal based. Plant based natural jute fiber reinforced polypropylene (PP) matrix composites (20 wt% fiber) were fabricated by compression molding. Bending strength (BS), bending modulus (BM), tensile strength (TS), Young’s modulus (YM), and impact strength (IS) of the composites were found 44.2 MPa, 2200 MPa, 41.3 MPa, 750 MPa and 12 kJ/m², respectively. Animal based natural B. mori silk fiber reinforced polypropylene (PP) matrix composites (20 wt% fiber) were fabricated in the same way and the mechanical properties were compared over the silk based composites. TS, YM, BS, BM, IS of silk fiber reinforced polypropylene composites were found 55.6 MPa, 760 MPa, 57.1 MPa, 3320 MPa and 17 kJ/m² respectively. Degradation of composites in soil was measured upto twelve weeks. It was found that plant based jute fiber/PP composite losses its strength more than animal based silk fiber/PP composite for the same period of time. The comparative study makes it clear that mechanical properties of silk/PP composites are greater than those values of jute/PP composites. But jute/PP composites are more degradable than silk/PP composites i.e., silk/PP composites retain their strength for a longer period than jute/PP composites.     

超细SiO2/NR复合材料的制备工艺及其力学性能

利用乳液共沉原理、正交实验法,研究了Na2SiO3·9H2O与盐酸在助剂的作用下生成的SiO2乳液与天然胶乳共凝制备超细SiO2/NR复合材料的工艺。结果表明:由Na2SiO3·9H2O的质量浓度、反应时间、反应温度3个因子适宜水平组合,采用乳液共沉法制备的超细SiO2/NR复合材料的300％定伸应力为6.43 MPa,拉伸强度为29.04 MPa,撕裂强度为56.88 kN/m,与纯胶、普通SiO2/NR复合材料相比,超细SiO2/NR复合材料的力学性能得到一定程度改善。在本实验条件下,超细SiO2/NR复合材料的最佳制备工艺条件(适宜的因子水平组合)是Na2SiO3·9H2O的质量浓度第1份为280 g/L、第2份为100 g/L,反应时间为30 min、反应温度为80℃。      

纳米CaCO3/NR复合材料制备工艺对其结构和性能的影响

采用SEM和力学性能测定研究了乳液共沉法制备工艺对纳米CaCO3/NR复合材料结构和力学性能的影响。结果表明:搅拌时间、胶乳质量分数、纳米CaCO3/NR填充量对复合材料结构与性能有显著影响,当它们分别为60min,15%~20%,20:100~40:100时,复合材料力学综合性能最好。纳米CaCO3对NR具有较好的补强效果。      

Thermotropic liquid crystal polymer reinforced poly(butylene terephthalate) composites to improve heat distortion temperature and mechanical properties

Thermotropic liquid crystal polymer (TLCP)-reinforced poly(butylene terephthalate) (PBT) composites were prepared by melt processing. The improvement in the mechanical properties and the processability of the PBT/TLCP composites was attributed to the reinforcing effect by TLCP phase and its well distribution in the PBT matrix. X-ray diffraction results demonstrated that a slow cooling process leads to the thicker lamellar structures and the formation of more regular crystallites in the composites. The incorporation of TLCP improves not only the tensile strength and flexural modulus but also the heat distortion temperature (HDT) of the PBT/TLCP composites. The HDT values of the composites were dependent on TLCP content. The improvement in the HDT values of the PBT/TLCP composites may be explained in terms with the increased flexural modulus, the development of more regular crystalline structures, and the enhancement of the ability of the composites to sustain the storage modulus by TLCP phase. In addition, the simple additivity rule makes it possible to predict the HDT values of the PBT/TLCP composites.     

Compatibilizing effects of polypropylene-g-itaconic acid on the polypropylene composites

We prepared long carbon fiber (LCF)-reinforced thermoplastic composites using a compatibilizer of itaconic acid grafted polypropylene (PP-g-IA). We confirmed the structure of PP-g-IA and investigated the compatibilizing effects of PPg- IA on LCF/polypropylene composites. The tensile strength, tensile moduli, flexural strength, and flexural moduli of the composites increased with increasing PP-g-IA content in the thermoplastic composites. Using single pull-out analyzing system, we found PP-g-IA improved interfacial strength between the carbon fiber and PP matrix. The thermal properties of the composites were measured by thermogravimetric analysis (TGA). We could observe that LCF enhanced the mechanical properties and thermal decomposition temperature of the polypropylene (PP) composites, compared with neat PP. The fractured surfaces of PP/PP-g-IA/LCF composites showed that PP-g-IA was effective for improving the interfacial adhesion between LCF and PP matrix.