The fracture and tribological evaluation of dental composite resin containing pre-polymerized particle fillers were investigated. Composite resins, e.g. metafil, silux plus, heliomolar and palfique estelite were selec...The fracture and tribological evaluation of dental composite resin containing pre-polymerized particle fillers were investigated. Composite resins, e.g. metafil, silux plus, heliomolar and palfique estelite were selected as specimens in order to evaluate the effects of pre-polymerized particle filler on the fracture and wear characteristics of composite resins. In the wear tests, a ball-on-flat wear test method was used. The friction coefficient of metafil was quite high. The wear resistance of silux plus and palfique estelite was better than that of metafil and heliomolar under the same experimental condition. The main wear mechanism of composite resins containing pre-polymerized particle fillers was an abrasive wear by brittle fracture of pre-polymerized particles and by debonding of fillers and matrix.展开更多
Water-dispersed polyurethane (PU) adhesive is a novel and highly efficient adhesive with broad application potential. In this study, the key parameters affecting the synthesis and application of this adhesive were exa...Water-dispersed polyurethane (PU) adhesive is a novel and highly efficient adhesive with broad application potential. In this study, the key parameters affecting the synthesis and application of this adhesive were examined, and optimal conditions were identified. The water-dispersed PU adhesive was successfully synthesized, and applied in the fastness test of pigment printing on cotton fabric. The data demonstrated that all the fastnesses of PU adhesive were better than that of the conventional PA one.展开更多
Bio-oil is a major product from pyrolysis of biomass which serves as a carbon source to produce carbon material due to its high reactivity towards polymerization itself or cross-polymerization with other organic feeds...Bio-oil is a major product from pyrolysis of biomass which serves as a carbon source to produce carbon material due to its high reactivity towards polymerization itself or cross-polymerization with other organic feedstocks.In this study,activation of polyaniline(PANI)mixed with wheat straw-derived bio-oil and K2C2O4 at 800°C was conducted,aiming to understand the effect of potential interactions of bio-oil with PANI on pore development of resulting activated carbon(AC).The results revealed cross-polymerization reactions between PANI and bio-oil during direct activation,which increased the yield of AC from 13.0%(calculated average)to 15.0%,the specific surface area from 1677.9 m^(2) g^(-1)(calculated average)to 1771.3 m^(2) g^(-1),and the percentage of micropores from 94.3%to 97.1%.In addition,pre-polymerization of PANI and bio-oil at 200°C before activation was also conducted.Such pretreatment could increase the AC yield from 13.0% to 23.3%,but the specific surface area decreased to 1381.8 m^(2) g^(-1).The pre-polymerization formed the organics that were more resistant towards cracking/gasification,but introduced oxygen-rich functionalities.This made AC highly hydrophilic,rendering a much higher capability for adsorption of phenol despite the smaller specific surface area.Additionally,the AC with developed pore structures facilitated dispersion of nickel in Ni/AC and enhanced the catalytic activity for hydrogenation of o-chloronitrobenzene and vanillin.展开更多
文摘The fracture and tribological evaluation of dental composite resin containing pre-polymerized particle fillers were investigated. Composite resins, e.g. metafil, silux plus, heliomolar and palfique estelite were selected as specimens in order to evaluate the effects of pre-polymerized particle filler on the fracture and wear characteristics of composite resins. In the wear tests, a ball-on-flat wear test method was used. The friction coefficient of metafil was quite high. The wear resistance of silux plus and palfique estelite was better than that of metafil and heliomolar under the same experimental condition. The main wear mechanism of composite resins containing pre-polymerized particle fillers was an abrasive wear by brittle fracture of pre-polymerized particles and by debonding of fillers and matrix.
文摘Water-dispersed polyurethane (PU) adhesive is a novel and highly efficient adhesive with broad application potential. In this study, the key parameters affecting the synthesis and application of this adhesive were examined, and optimal conditions were identified. The water-dispersed PU adhesive was successfully synthesized, and applied in the fastness test of pigment printing on cotton fabric. The data demonstrated that all the fastnesses of PU adhesive were better than that of the conventional PA one.
基金This work was supported by the National Natural Science Foundation of China(No.52276195)the Program for supporting innovative research from Jinan(202228072)the Program of agricultural development from Shandong(SD2019NJ015).
文摘Bio-oil is a major product from pyrolysis of biomass which serves as a carbon source to produce carbon material due to its high reactivity towards polymerization itself or cross-polymerization with other organic feedstocks.In this study,activation of polyaniline(PANI)mixed with wheat straw-derived bio-oil and K2C2O4 at 800°C was conducted,aiming to understand the effect of potential interactions of bio-oil with PANI on pore development of resulting activated carbon(AC).The results revealed cross-polymerization reactions between PANI and bio-oil during direct activation,which increased the yield of AC from 13.0%(calculated average)to 15.0%,the specific surface area from 1677.9 m^(2) g^(-1)(calculated average)to 1771.3 m^(2) g^(-1),and the percentage of micropores from 94.3%to 97.1%.In addition,pre-polymerization of PANI and bio-oil at 200°C before activation was also conducted.Such pretreatment could increase the AC yield from 13.0% to 23.3%,but the specific surface area decreased to 1381.8 m^(2) g^(-1).The pre-polymerization formed the organics that were more resistant towards cracking/gasification,but introduced oxygen-rich functionalities.This made AC highly hydrophilic,rendering a much higher capability for adsorption of phenol despite the smaller specific surface area.Additionally,the AC with developed pore structures facilitated dispersion of nickel in Ni/AC and enhanced the catalytic activity for hydrogenation of o-chloronitrobenzene and vanillin.
