Ultrafine full-vulcanized polybutadiene rubber（UFBR） with particle sizes of ca.50―100 nm were used for modifying mechanical and processing performances of polypropylene（PP） with PP-g-maleic anhydride（PP-g-MA） a...Ultrafine full-vulcanized polybutadiene rubber（UFBR） with particle sizes of ca.50―100 nm were used for modifying mechanical and processing performances of polypropylene（PP） with PP-g-maleic anhydride（PP-g-MA） as a compatibilizer for enhancing the interfacial adhesion between the two components.The morphology,dynamical rheology response and mechanical properties of the blends were characterized by means of SEM,rheometer and tensile test,respectively.The results show that the ternary PP/UFBR blends compatibilized with PP-g-MA possess rheological behaviors like highly branched PP,while no obvious strain hardening is observed in its control binary PP/UFBR blends,a low level of PP-g-MA in PP/UFBR blends can even endow the material with rheological characteristics of high melt strength materials like highly branched PP.The enhancement interfacial interaction between the UFBR particles and PP matrix accounting for the rheological behavior of compatibilized blends and effectiveness of PP-g-MA were proposed and proved.展开更多
The transient liquid phase diffusion bonding of Si 3N 4 ceramics with Ti/Ni/Ti and Al/Ti/Al multiple interlayers was performed. The formation of intermetallic compounds in situ and their effects on the joints streng...The transient liquid phase diffusion bonding of Si 3N 4 ceramics with Ti/Ni/Ti and Al/Ti/Al multiple interlayers was performed. The formation of intermetallic compounds in situ and their effects on the joints strengths were investigated. The Ti/Ni/Ti interlayers produce NiTi and Ni 3Ti layers with considerable room temperature ductility and high elevated temperature strength to strengthen the bonding zone metals and the joints. The joints with 142 MPa shear strength at room temperature and 88 MPa shear strength at 800 ℃ are achieved under appropriate parameters, respectively. Al/Ti/Al interlayers transform into a special bonding zone metal with a large amount of Al 3Ti particles and a small amount of Al based solid solution, and in this case, the joints are strengthened significantly. Their strengths at room temperature and 600 ℃ reach 90 MPa and 30 MPa, respectively.展开更多
为探究2种不同类型的多糖对羊皮明胶凝胶特性和结构的影响,利用卡拉胶与魔芋胶复配,银耳多糖作为安全性改性剂,研究羊皮明胶凝胶强度、质构、色泽、熔化温度及结构的变化。结果表明,卡拉胶与魔芋胶复配可显著提高羊皮明胶凝胶的凝胶强...为探究2种不同类型的多糖对羊皮明胶凝胶特性和结构的影响,利用卡拉胶与魔芋胶复配,银耳多糖作为安全性改性剂,研究羊皮明胶凝胶强度、质构、色泽、熔化温度及结构的变化。结果表明,卡拉胶与魔芋胶复配可显著提高羊皮明胶凝胶的凝胶强度和质构特性,在复配胶质量比为2∶1时,凝胶强度和硬度最大,分别为(625.75±5.28)g、(172.26±0.5)g。同时,熔化温度提高至30℃以上。加入银耳多糖后,增强了复合凝胶的粘连性。L^(*)值无显著变化,而a^(*)值和b^(*)值显著提高。红外光谱图表明,亲水胶体减少了明胶凝胶分子内氢键的形成。添加银耳多糖使羰基向高波数移动。加入多糖后羊皮明胶衍射峰逐渐变得平坦,三股螺旋和左螺旋的生成被破坏。扫描电镜(scanning electron microscope,SEM)结果表明添加适量多糖后,改善了复合凝胶的网络结构,使得网络结构更加均匀致密。综上所述,卡拉胶与魔芋胶复配主要改善羊皮明胶的质构特性和熔化温度,银耳多糖主要影响明胶凝胶的色泽和粘连性、回弹力。2种多糖都对羊皮明胶的特性产生了积极的影响,这可为以后羊皮明胶在食品上的应用提供理论依据和技术指导。展开更多
基金Supported by the National High Technology Research and Development Program of China(No.2002AA333040)the Special Funds of Science and Technology Bureau of Harbin for Hi-Tech Research,China(No.2007AA4BG140)
文摘Ultrafine full-vulcanized polybutadiene rubber（UFBR） with particle sizes of ca.50―100 nm were used for modifying mechanical and processing performances of polypropylene（PP） with PP-g-maleic anhydride（PP-g-MA） as a compatibilizer for enhancing the interfacial adhesion between the two components.The morphology,dynamical rheology response and mechanical properties of the blends were characterized by means of SEM,rheometer and tensile test,respectively.The results show that the ternary PP/UFBR blends compatibilized with PP-g-MA possess rheological behaviors like highly branched PP,while no obvious strain hardening is observed in its control binary PP/UFBR blends,a low level of PP-g-MA in PP/UFBR blends can even endow the material with rheological characteristics of high melt strength materials like highly branched PP.The enhancement interfacial interaction between the UFBR particles and PP matrix accounting for the rheological behavior of compatibilized blends and effectiveness of PP-g-MA were proposed and proved.
文摘The transient liquid phase diffusion bonding of Si 3N 4 ceramics with Ti/Ni/Ti and Al/Ti/Al multiple interlayers was performed. The formation of intermetallic compounds in situ and their effects on the joints strengths were investigated. The Ti/Ni/Ti interlayers produce NiTi and Ni 3Ti layers with considerable room temperature ductility and high elevated temperature strength to strengthen the bonding zone metals and the joints. The joints with 142 MPa shear strength at room temperature and 88 MPa shear strength at 800 ℃ are achieved under appropriate parameters, respectively. Al/Ti/Al interlayers transform into a special bonding zone metal with a large amount of Al 3Ti particles and a small amount of Al based solid solution, and in this case, the joints are strengthened significantly. Their strengths at room temperature and 600 ℃ reach 90 MPa and 30 MPa, respectively.
文摘为探究2种不同类型的多糖对羊皮明胶凝胶特性和结构的影响,利用卡拉胶与魔芋胶复配,银耳多糖作为安全性改性剂,研究羊皮明胶凝胶强度、质构、色泽、熔化温度及结构的变化。结果表明,卡拉胶与魔芋胶复配可显著提高羊皮明胶凝胶的凝胶强度和质构特性,在复配胶质量比为2∶1时,凝胶强度和硬度最大,分别为(625.75±5.28)g、(172.26±0.5)g。同时,熔化温度提高至30℃以上。加入银耳多糖后,增强了复合凝胶的粘连性。L^(*)值无显著变化,而a^(*)值和b^(*)值显著提高。红外光谱图表明,亲水胶体减少了明胶凝胶分子内氢键的形成。添加银耳多糖使羰基向高波数移动。加入多糖后羊皮明胶衍射峰逐渐变得平坦,三股螺旋和左螺旋的生成被破坏。扫描电镜(scanning electron microscope,SEM)结果表明添加适量多糖后,改善了复合凝胶的网络结构,使得网络结构更加均匀致密。综上所述,卡拉胶与魔芋胶复配主要改善羊皮明胶的质构特性和熔化温度,银耳多糖主要影响明胶凝胶的色泽和粘连性、回弹力。2种多糖都对羊皮明胶的特性产生了积极的影响,这可为以后羊皮明胶在食品上的应用提供理论依据和技术指导。
