Ni Shuzhen,Wang Chunjian,Bian Huiyang,Yu Zhihuai,Jiao Liang,Fang Guigan,Dai Hongqi
The exploitation of light-weight paper-based cellulosic materials (PBCM) is beneficial for protecting the environment, cutting production cost and improving utilization efficiency of cellulose. In this study, a simple reaction using PEI (Polyethyleneimine) and KH560 was reported to improve the physical performance and hydrophobicity of PBCM. FTIR spectra indicated that the epoxide group of KH560 disappeared during reaction with PEI. Physical properties and hydrophobicity of the dried PBCM were determined after impregnation with the mixture of enzymatic starch and PEI-KH560. Compared with the control, the dry tensile index, wet tensile index and folding endurance of PBCM were increased by 27.1, 61.4 and 137.5%, respectively, when the dosage of PEI-KH560 was 1.35%. If starch (6.35 g/m 2 ) was added together with PEI-KH560 (1.35%), the dry tensile index could increase by 98.6%. The pH and alkaline reserve value of PBCM were also improved. The addition of PEI-KH560 improved the thermal stability of starch, thus was beneficial for the increase of thermal stability of PBCM. This novel method adopted in this study to improve the physical performance, hydrophobicity and alkaline reserve value of PBCM provided a cost-efficient and simple way to broaden its potential application fields.
Yi Zhao,Shuzhen Ni,Ying Gao,Xin Zhang,Xingxiang Ji,Fengshan Zhang
Novel eco-friendly strength agent has inspired much attention of researchers. Herein, the PEI-KH560 prepared by PEI (polyethyleneimine) and KH560 (γ-glycidyl ether propyl trimethoxysilane) was added in the pulp suspension to enhance the paper performance. The results showed that the m(PEI):m(KH560) ratio and PEI's molecular weight were closely related with the paper strength and hydrophobicity. The SEM morphology of paper surface showed that the fiber-fiber crosslinking reached the tightest, at the optimal m(PEI):m(KH560) ratio and PEI's molecular weight. The results showed that when the M w (molecular weight) of PEI was 10,000 and the m(PEI):m(KH560) ratio was 1:2, the PEI-KH560 presented the best strengthening performance on the paper strength and hydrophobicity. Dry tensile index and wet tensile index could reach 29.9 N·m/g and 1.37 N·m/g after adding the PEI 10000 -KH560 in pulp suspension before the paper formation. Further, the effect of process conditions (temperature, time, the addition amount, and pulp concentration) on the strength and hydrophobicity of paper network structure was investigated, after adding PEI-KH560 into the pulp suspension. It was of great significance for studying the mechanism between the chemical structures of PEI-KH560 and paper performance, which provided valuable theoretical practice on the preparation of novel strength agent.
In recent years, researchers have put much attention on the improvements and upgrades of novel wet strength agent in the papermaking fields, especially in the usage of household paper. Herein, PEI M -KH560 by polyethyleneimine (PEI) and γ-glycidyl ether propyl trimethoxysilane (KH560) was synthesized with five molecular weights (Mw) of PEI at 600, 1800, 10,000, 70,000 and 750,000. Results showed that the molecular weight greatly influenced the physicochemical properties of PEI-KH560, such as the size and thermal stability. The intrinsic cationic charge of PEI-KH560 provided the bonding sites with the paper fibers, forming strengthened fiber-fiber joints. It was shown that the dry, wet strength and hydrophobicity of cellulosic paper sheets were obviously improved. When the m (PEI):m(KH560) is 1:2, the strength of papers after sizing by Mw of PEI at 600 and 1800 is the most obvious, with the dry strength increased by 227.9 % and 187.5 %, and the wet strength increased by 183.8 % and 207.8 %, respectively. The maximum hydrophobicity was found at the PEI 1800 -KH560 with the contact angle value of 130.6°. The resultant environmental-friendly agent (PEI-KH560) obtained in this work provides valuable significance for the preparation of household and food packaging paper.
危险品化学品经营许可证（带存储）