考察了熔融挤出后施加的牵伸比和增容剂对聚丙烯(PP)/热致液晶聚合物(TLCP)原位复合材料中TLCP分散相形貌的影响。结果表明,复合材料中的TLCP相随着牵伸比的增大逐渐形成良好的微纤结构,TLCP微纤的长径比随牵伸比增大而增大;当体系中... 考察了熔融挤出后施加的牵伸比和增容剂对聚丙烯(PP)/热致液晶聚合物(TLCP)原位复合材料中TLCP分散相形貌的影响。结果表明,复合材料中的TLCP相随着牵伸比的增大逐渐形成良好的微纤结构,TLCP微纤的长径比随牵伸比增大而增大;当体系中加入增容剂PP g MAH后,体系中TLCP在较小的牵伸速率下即可形成长径比很大的微纤结构。将上述所得原位复合材料与玻纤在200℃(低于TLCP熔融温度)下熔融挤出制得玻纤和液晶聚合物微纤混杂增强的材料。实验证明,在此加工温度下液晶聚合物形态得到较好保持,注射样品中不存在原位复合材料中典型的"皮 芯"形貌。同时,增容剂PP g MAH还明显改善了玻纤与基体之间的界面粘结。展开更多
The preparation of X-zeolite powder was investigated in hydrothermal system, the crystal growth process of X-zeolite in hydrothermal condition was characterized by means of X-ray diffraction, scanning electron microsc...The preparation of X-zeolite powder was investigated in hydrothermal system, the crystal growth process of X-zeolite in hydrothermal condition was characterized by means of X-ray diffraction, scanning electron microscope and infrared ray. The results show that X-zeolite powder with uniform granularity and intact crystal shape can be obtained in hydrothermal system of acid-treated stellerite KG-*5CD*2KG-*9NaOHKG-*5CD*2KG-*9NaAl（OH）4KG-*5CD*2KG-*9H2O; the crystallite size is in the range of 2CD*23μm. The best reaction time of hydrothermal preparation is 6h. The formation phases of X-zeolite crystal are as follows: dissolution of feedstocks → formation of [SiO4] 4- and [AlO4] 5- tetrahedron, many-membered ring, β cage → formation of crystal nucleus and nano-particle → aggregation growth of nano-particle → coalescence growth of crystallite. The crystal habits of X-zeolite are intimately related with crystallization orientation of β cage in crystal and with its coupling stability on every crystal face family.展开更多
Transient liquid phase(TLP)bonding is a potential high-temperature(HT)electron packaging technology that is used inthe interconnection of wide band-gap semiconductors.This study focused on the mechanism of intermetall...Transient liquid phase(TLP)bonding is a potential high-temperature(HT)electron packaging technology that is used inthe interconnection of wide band-gap semiconductors.This study focused on the mechanism of intermetallic compounds(IMCs)evolution in Ag/Sn TLP soldering at different temperatures.Experimental results indicated that morphologies of Ag3Sn grains mainlywere scallop-type,and some other shapes such as prism,needle,hollow column,sheet and wire of Ag3Sn grains were also observed,which was resulted from their anisotropic growths.However,the scallop-type Ag3Sn layer turned into more planar with prolongingsoldering time,due to grain coarsening and anisotropic mass flow of Ag atoms from substrate.Furthermore,a great amount ofnano-Ag3Sn particles were found on the surfaces of Ag3Sn grains,which were formed in Ag-rich areas of the molten Sn and adsorbedby the Ag3Sn grains during solidification process.Growth kinetics of the Ag3Sn IMCs in TLP soldering followed a parabolicrelationship with soldering time,and the growth rate constants of250,280and320°C were calculated as5.83×10-15m2/s,7.83×10-15m2/s and2.83×10-14m2/s,respectively.Accordingly,the activation energy of the reaction was estimated about58.89kJ/mol.展开更多
文摘 考察了熔融挤出后施加的牵伸比和增容剂对聚丙烯(PP)/热致液晶聚合物(TLCP)原位复合材料中TLCP分散相形貌的影响。结果表明,复合材料中的TLCP相随着牵伸比的增大逐渐形成良好的微纤结构,TLCP微纤的长径比随牵伸比增大而增大;当体系中加入增容剂PP g MAH后,体系中TLCP在较小的牵伸速率下即可形成长径比很大的微纤结构。将上述所得原位复合材料与玻纤在200℃(低于TLCP熔融温度)下熔融挤出制得玻纤和液晶聚合物微纤混杂增强的材料。实验证明,在此加工温度下液晶聚合物形态得到较好保持,注射样品中不存在原位复合材料中典型的"皮 芯"形貌。同时,增容剂PP g MAH还明显改善了玻纤与基体之间的界面粘结。
文摘The preparation of X-zeolite powder was investigated in hydrothermal system, the crystal growth process of X-zeolite in hydrothermal condition was characterized by means of X-ray diffraction, scanning electron microscope and infrared ray. The results show that X-zeolite powder with uniform granularity and intact crystal shape can be obtained in hydrothermal system of acid-treated stellerite KG-*5CD*2KG-*9NaOHKG-*5CD*2KG-*9NaAl（OH）4KG-*5CD*2KG-*9H2O; the crystallite size is in the range of 2CD*23μm. The best reaction time of hydrothermal preparation is 6h. The formation phases of X-zeolite crystal are as follows: dissolution of feedstocks → formation of [SiO4] 4- and [AlO4] 5- tetrahedron, many-membered ring, β cage → formation of crystal nucleus and nano-particle → aggregation growth of nano-particle → coalescence growth of crystallite. The crystal habits of X-zeolite are intimately related with crystallization orientation of β cage in crystal and with its coupling stability on every crystal face family.
基金Project(51375260) supported by the National Natural Science Foundation of China
文摘Transient liquid phase(TLP)bonding is a potential high-temperature(HT)electron packaging technology that is used inthe interconnection of wide band-gap semiconductors.This study focused on the mechanism of intermetallic compounds(IMCs)evolution in Ag/Sn TLP soldering at different temperatures.Experimental results indicated that morphologies of Ag3Sn grains mainlywere scallop-type,and some other shapes such as prism,needle,hollow column,sheet and wire of Ag3Sn grains were also observed,which was resulted from their anisotropic growths.However,the scallop-type Ag3Sn layer turned into more planar with prolongingsoldering time,due to grain coarsening and anisotropic mass flow of Ag atoms from substrate.Furthermore,a great amount ofnano-Ag3Sn particles were found on the surfaces of Ag3Sn grains,which were formed in Ag-rich areas of the molten Sn and adsorbedby the Ag3Sn grains during solidification process.Growth kinetics of the Ag3Sn IMCs in TLP soldering followed a parabolicrelationship with soldering time,and the growth rate constants of250,280and320°C were calculated as5.83×10-15m2/s,7.83×10-15m2/s and2.83×10-14m2/s,respectively.Accordingly,the activation energy of the reaction was estimated about58.89kJ/mol.
