Microfibrillated cellulose(MFC)was obtained by mechanical grinding of different pulps.MFC-modified ground calcium carbonate(GCC)was prepared in two different ways,designated MFC-GCC composite filler and MFC-GCC flocs ...Microfibrillated cellulose(MFC)was obtained by mechanical grinding of different pulps.MFC-modified ground calcium carbonate(GCC)was prepared in two different ways,designated MFC-GCC composite filler and MFC-GCC flocs filler.The opacity of pulp handsheets loaded with MFCmodified GCC was measured.The effects of MFC originated from different pulps,pretreatment method,and filler modification on the opacity of handsheets loaded with MFC-modified GCC were discussed.The results show that MFC originated from alkaline peroxide mechanical pulp(APMP)was optimal for improving the opacity of the handsheets and PFI grinding pretreatment for MFC provided a denser structure in the corresponding MFCAPMP-GCC floc filler while enzyme pretreatment was more effective in increasing the opacity of the filled paper.Under the experimental conditions,the opacity of handsheets increased from 81.0%to 82.7%when the unmodified GCC was replaced by an equivalent amount of MFCAPMP-GCC composite filler,while other properties were unchanged.展开更多
High-calcium fly ash (HCFA)—a residue of high-temperature coal combustion at thermal power plants, in combination with sodium carbonate presents an effective hardening activator of ground granulated blast-furnace sla...High-calcium fly ash (HCFA)—a residue of high-temperature coal combustion at thermal power plants, in combination with sodium carbonate presents an effective hardening activator of ground granulated blast-furnace slag (GGBFS). Substitution of 10% - 30% of GGBFS by HCFA and premixing of 1% - 3% Na2CO3 to this dry binary binder was discovered to give mortar compression strength of 10 - 30 to 30 - 45 MPa at 7 and 28 days when moist cured at ambient temperature. High-calcium fly ash produced from low-temperature combustion of fuel, like in circulating fluidized bed technology, reacts with water readily and is itself a good hardening activator for GGBFS, so introduction of Na<sub>2</sub>CO<sub>3</sub> into such mix has no noticeable effect on the mortar strength. However, low-temperature HCFA has higher water demand, and the strength of mortar is compromised by this factor. As of today, our research is still ongoing, and we expect to publish more data on different aspects of durability of proposed GGBFS-HCFA binder later.展开更多
尽可能低的吸油值是人造石材对重质碳酸钙填料的主要技术指标要求之一。选取聚乙二醇-200、一缩二乙二醇、三乙醇胺和氨基硅油-804为改性剂,采用干法对重质碳酸钙填料进行表面改性,以吸油值为表征手段,研究了改性剂品种及其用量对重质...尽可能低的吸油值是人造石材对重质碳酸钙填料的主要技术指标要求之一。选取聚乙二醇-200、一缩二乙二醇、三乙醇胺和氨基硅油-804为改性剂,采用干法对重质碳酸钙填料进行表面改性,以吸油值为表征手段,研究了改性剂品种及其用量对重质碳酸钙填料吸油值影响的规律,并结合红外光谱分析和热重分析对改性机理进行了讨论。结果表明:改性样品的吸油值随改性剂用量的增大而下降,采用氨基硅油-804改性剂且用量为1.00%时,改性样品的吸油值最低,达到0.115 m L/g,改性后样品的热稳定性最好,热分解温度为325℃;4种改性剂均与重质碳酸钙粉体表面的官能团羟基发生了化学键合作用。展开更多
文摘Microfibrillated cellulose(MFC)was obtained by mechanical grinding of different pulps.MFC-modified ground calcium carbonate(GCC)was prepared in two different ways,designated MFC-GCC composite filler and MFC-GCC flocs filler.The opacity of pulp handsheets loaded with MFCmodified GCC was measured.The effects of MFC originated from different pulps,pretreatment method,and filler modification on the opacity of handsheets loaded with MFC-modified GCC were discussed.The results show that MFC originated from alkaline peroxide mechanical pulp(APMP)was optimal for improving the opacity of the handsheets and PFI grinding pretreatment for MFC provided a denser structure in the corresponding MFCAPMP-GCC floc filler while enzyme pretreatment was more effective in increasing the opacity of the filled paper.Under the experimental conditions,the opacity of handsheets increased from 81.0%to 82.7%when the unmodified GCC was replaced by an equivalent amount of MFCAPMP-GCC composite filler,while other properties were unchanged.
文摘High-calcium fly ash (HCFA)—a residue of high-temperature coal combustion at thermal power plants, in combination with sodium carbonate presents an effective hardening activator of ground granulated blast-furnace slag (GGBFS). Substitution of 10% - 30% of GGBFS by HCFA and premixing of 1% - 3% Na2CO3 to this dry binary binder was discovered to give mortar compression strength of 10 - 30 to 30 - 45 MPa at 7 and 28 days when moist cured at ambient temperature. High-calcium fly ash produced from low-temperature combustion of fuel, like in circulating fluidized bed technology, reacts with water readily and is itself a good hardening activator for GGBFS, so introduction of Na<sub>2</sub>CO<sub>3</sub> into such mix has no noticeable effect on the mortar strength. However, low-temperature HCFA has higher water demand, and the strength of mortar is compromised by this factor. As of today, our research is still ongoing, and we expect to publish more data on different aspects of durability of proposed GGBFS-HCFA binder later.
文摘尽可能低的吸油值是人造石材对重质碳酸钙填料的主要技术指标要求之一。选取聚乙二醇-200、一缩二乙二醇、三乙醇胺和氨基硅油-804为改性剂,采用干法对重质碳酸钙填料进行表面改性,以吸油值为表征手段,研究了改性剂品种及其用量对重质碳酸钙填料吸油值影响的规律,并结合红外光谱分析和热重分析对改性机理进行了讨论。结果表明:改性样品的吸油值随改性剂用量的增大而下降,采用氨基硅油-804改性剂且用量为1.00%时,改性样品的吸油值最低,达到0.115 m L/g,改性后样品的热稳定性最好,热分解温度为325℃;4种改性剂均与重质碳酸钙粉体表面的官能团羟基发生了化学键合作用。
