增湿强剂PAEP的制备及性能

采用聚乙烯醇(PVA)对传统湿增强剂聚酰胺多胺环氧氯丙烷(PAE)树脂进行化学改性,制备了一种PAEP湿增强剂。并在抄纸过程中引入PAEP与有机硼复合湿强剂,进一步增加纤维间的交联。采用IR、SEM、Zeta电位仪、TG对其结构、性能进行了表征;探讨了PAEP在纤维中的吸附行为,以及PAE、PAEP、PAEP-有机硼用量对纸张湿强性能的影响。结果表明,随着PAEP加入量由2.5 mg/g增加到30 mg/g,其在纤维中的饱和吸附量从2.33 mg/g增加到8.14 mg/g,吸附效率由93.2%降低到27.1%;与PAE相比,经PAEP、PAEP-有机硼处理后的纸张热降解残渣量分别增多122.67%,269.60%;当PAEP-有机硼中有机硼的质量分数为50%(以PAEP质量计,下同)时,纸张的干、湿抗张指数分别提高22.66%和79.46%,抗张指数保留率增加46.35%。在相同质量下,与阳离子聚丙烯酰胺和阳离子淀粉相比,PAEP-有机硼复合湿强剂亦具有较佳的增强效果。     

GMA改性水溶性PVA纤维的制备及其增强作用

通过悬浮接枝共聚法以甲基丙烯酸缩水甘油酯(GMA)为功能化单体,制备了一种具有反应活性的聚乙烯醇(PVA)纤维。研究了纸张中改性PVA纤维的质量分数和干燥温度对纸张耐折度、抗张强度以及湿强度的影响。结果表明,当纸张中改性PVA纤维的质量分数为9%,纸张干燥温度为110℃时,纸张获得较佳强度,耐折度为72次,干拉力为70.4 N,湿拉力为15.6 N。热重分析(TGA)表明,GMA在纤维表面发生了接枝共聚反应。原子力显微镜(AFM)照片显示,改性PVA纤维形成了表面乳突结构,有助于形成疏水表面。纸张的扫描电镜(SEM)照片显示,添加改性PVA纤维的纸张,其耐折测试断裂面纤维的长度较短,且纸张表面PVA纤维的溶解程度显著下降。     

改性聚乙烯醇胶黏剂的研究

研究了固含量高、耐水性好的聚乙烯醇胶的合成工艺条件。首先,通过单因素实验,以黏度为指标,优化了氧化剂、催化剂、疏水剂的用量以及氧化反应pH值、温度、时间;通过正交实验,分别考察了氧化剂、催化剂、疏水剂对改性PVA胶性能的影响。结果表明:反应时间40min,反应温度50~55℃,反应pH值为5,H2O2为0.013mol,FeSO4·7H2O为0.15g,尿素为1.8g,改性PVA胶综合性能最好,胶黏剂干胶合强度为2.23MPa,湿胶合强度为1.60MPa。     

封闭聚氨酯纸张增强剂的制备及应用

以咪唑为封闭剂,异佛尔酮二异氰酸酯(IPDI)、聚己内酯二醇、N-甲基二乙醇胺(MDEA)、己二酸二酰肼(ADH)、双酚A、自制N-[(1,1-二甲基-2-乙酰基)乙基]-β-二羟乙氨基丙酰胺(DDP)为原料制备了封闭型阳离子聚氨酯纸张增强剂(CBPU)。用FTIR、1HNMR、动态激光光散射(DLLS)和SEM对CBPU分子结构、乳液粒径及纸张表面形貌进行了表征,研究了封闭率对乳液粒径的影响。探讨了封闭率及乳液添加量对纸张力学性能的影响。结果表明,产物分子结构中出现了叔胺基、咪唑环和氨基甲酸酯结构。乳液粒径随着封闭率的增加而增大。增加CBPU的封闭率及用量能明显提高纸张的强度指标,尤其是湿强度。当CBPU封闭率及添加量分别为10%与5%(以绝干浆质量计)时,纸张湿强度为30.32%。     

聚丙烯酰胺系纸张增强剂研究综述

以聚丙烯酰胺(PAM)为基料的纸张增强剂(简称纸强剂)主要用作干强剂。这种合成聚合物与淀粉和天然胶相比,其分子量和阴、阳离子基团的取代度容易调整,有更好的增强效果。而且,它还能提高填料和细纤维的留着率,改进松香施胶效率和加快排水过滤使纸页容易干燥。它的应用范围也很广,诸如印刷纸、牛皮纸、衬纸和纸板等都可使用这种纸强剂。由于它有很多优点,近年来国外在这方面的研究相当活跃。     

曼尼兹改性聚丙烯酰胺的合成及其在造纸工业中的增强作用

叙述了ＰＡＭ进行胺甲基化反应的过程。,讨论反庆配比,温度,时间对产物胺化率的影响,以及产物对纸质的增强作用。     

氧化石墨烯改性聚乙烯醇纳滤膜的制备及性能研究

以聚砜超滤膜为支撑层,以聚乙烯醇为分离层材料,通过向聚乙烯醇中添加氧化石墨烯,制备了氧化石墨烯改性聚乙烯醇纳滤膜。分别以氯化钠溶液和硫酸钠溶液为原料液,测试了改性纳滤膜的分离性能,并与聚乙烯醇纳滤膜进行了对比。结果表明,与聚乙烯醇纳滤膜相比,氧化石墨烯改性聚乙烯醇纳滤膜的通量有一定下降,但对盐的截留率显著提高,对硫酸钠的截留率最高达96.1%,对氯化钠的截留率在30%左右,显示出较好的分盐性能。     

化学交联聚乙烯醇降失水剂的合成及中试研究

聚乙烯醇与交联剂戊二醛在60℃、酸性环境下的水溶液中发生反应,生成化学交联聚乙烯醇降失水剂.研究结果表明:当6％聚乙烯醇和5％戊二醛的质量比为300:1.4,6％聚乙烯醇和0.1mol/L盐酸的质量比为300:47时,得到API滤失量较低的产品.线形方程生产的中试产品的性能和实验室合成样品保持一致.加入1.2％BWOC...     

环氧化天然橡胶/聚乙烯醇半互穿网络聚合物的结构与性能

以马来酸酐(MAH)为交联剂,制备了以环氧化天然橡胶(ENR)和聚乙烯醇(PVA)为互穿组分的半互穿网络聚合物(Semi-IPN ENR/PVA),通过红外光谱、扫描电镜、X射线衍射仪(XRD)和电子万能材料试验机,研究了Semi-IPN ENR/PVA的形态结构、结晶性能和力学性能。结果表明,ENR与PVA形成了具有微相分离形态结构的Semi-IPN ENR/PVA。MAH的加入降低了PVA的结晶度,在一定程度上提高了ENR和PVA的相容性。Semi-IPN ENR/PVA的力学性能均比交联前增强,其中交联后断裂伸长率和撕裂强度均随着MAH含量的增加而逐步下降,而硬度则没有随着MAH含量的增加发生明显变化。     

Characterization of polyamideamine‐epichlorohydrin (PAE) resin: Roles of azetidinium groups and molecular mass of PAE in wet strength development of paper prepared with PAE

Polyamideamine‐epichlorohydrin (PAE) resin is a crosslinked heteropolymer having cationic charges, and has been widely used as a wet strength agent of paper in the papermaking process. In this study, more accurate molecular mass values of PAE were determined by size exclusion chromatography attached with a multi angle laser light scattering detector (SEC‐MALS). The obtained weight average molecular mass (M_w) values of commercial and laboratory‐made PAE samples were 1,140,000 and 494,000, respectively, and these values were much higher than those reported so far. SEC‐MALS analysis also revealed that PAE molecules had highly crosslinked structures and extremely wide molecular mass distributions. Molecular mass values and content of 3‐hydroxy‐azetidinium (AZR) groups in PAE and PAE intermediates during the course of PAE synthesis were also determined by the SEC‐MALS and ¹H NMR methods, and the relationships between these values and the wet strength development of handsheets prepared with these PAE samples were studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2249–2255, 2005     

纸张湿强剂研究进展

造纸用湿强剂具有巨大的市场潜力和发展前景。本文简要介绍6种重要的湿强树脂及其湿强机理,综述它们的制备方法和特点,以及它们的发展情况。     

低有机氯含量PAE基纸张湿强剂的制备及性能评价

利用二乙烯三胺和己二酸为原料,对甲苯磺酸为催化剂合成聚酰胺,在聚酰胺和环氧氯丙烷的反应中加入三乙胺和阳离子改性剂,反应得到改性聚酰胺环氧氯丙烷(PAE)树脂,将其用作纸张湿强剂,进行浆内施胶得到了改性PAE树脂施胶纸张。通过傅里叶变换红外光谱(FTIR)及溶液稳定性测试对改性PAE树脂的结构和稳定性进行了表征,讨论了温度和三乙胺用量对有机氯含量的影响、三乙胺及阳离子改性剂用量对改性PAE树脂施胶纸张物理性能的影响。结果表明,当温度为50℃、三乙胺用量为7.4%(相对于反应物总质量)、阳离子改性剂用量为24.6%(相对于反应物总质量)时,制备的改性PAE树脂中有机氯含量为0.067%(相对于PAE树脂总质量),低于国家标准规定的0.7%,并可在室温下稳定放置。当改性PAE树脂添加量为质量分数1.6%,其浆内施胶效果最佳,浆内zeta电位为-1.2mV,纸张接触角为63.56°,改性PAE树脂施胶纸张与原纸相比干抗张指数、湿抗张指数、撕裂指数和耐折度分别提高了41%、13%、32.8%和27%,纸张物理性能明显增强。     

Combination of bifunctional aldehydes and poly(vinyl alcohol) as the crosslinking systems to improve paper wet strength

Two bifunctional aldehydes (i.e., glyoxal and glutaraldehyde) are used as the crosslinking agents to improve paper wet strength in the presence of fully hydrolyzed poly(vinyl alcohol) (PVA) as a co‐reactant. These bifunctional aldehydes alone improve paper wet strength but diminish its folding endurance. The use of PVA as a co‐reactant not only improves paper wet strength but also increases its dry strength and folding endurance. Glutaraldehyde is able to impart much higher levels of wet strength to the treated paper than glyoxal when a catalyst is present. The wet strength of the treated paper increases as the amount of PVA added is increased, and it also increases as the molecular weight (M_w) of the PVA increases. The data suggest that the reaction between glutaraldehyde and PVA promotes the formation of interfiber crosslinking, thus improving the wet strength without diminishing the flexibility of the treated paper. The use of a catalyst is critical to achieve high levels of durable wet strength of the treated paper. We studied the effects of different Lewis acids as the catalysts for crosslinking of pulp cellulose by glutaraldehyde and found that Zn(NO₃)₂ is the most effective one. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1673–1680, 2004     

滑石粉-淀粉增强剂的制备及其性能研究

利用滑石粉和淀粉制备了一种造纸增强剂,研究了滑石粉和淀粉比例对该造纸增强剂的润胀能力、白度和接触角的影响以及交联剂用量对增强剂润胀能力的影响,并将其应用于纸张抄造中,研究了其对纸张性能的影响。结果表明,随着淀粉在增强剂中比例的提高,增强剂的润胀能力提高,白度降低,接触角减小。交联剂用量较高时,增强剂的润胀能力有所降低。和使用未经处理的纯滑石粉相比,滑石粉-淀粉增强剂用量为15%~20%时,抗张强度可提高20%,耐破度可提高44%,耐折度可提高130%。     

环境友好型聚酰胺环氧氯丙烷湿强剂的性能研究

聚酰胺聚胺环氧氯丙烷树脂(PAE)是在中性条件下固化的应用较广泛的湿强剂,但它具有固含量不高,产品中含有有机氯等缺点.考察了采用改进的溶液聚合合成反应条件与有机胺后处理相结合的新工艺开发的环境友好型低氯高固含量PAE湿强树脂对纸张湿强度影响.结果表明,该低氯高固含量PAE树脂在合适的条件下能显著的提高纸张的湿强性,是一种具有市场开发前景新型的湿强剂.     

Influence of retention system and curing on paper wet strength improvement by a copolymer containing glycidyl groups

The copolymer (PGS) synthesized by polymerization of glycidyl methacrylate with styrene had a significant effect on paper wet strength. Factors such as retention aids, curing temperature, and curing time were investigated. The results showed that among four kinds of partially aminated poly N‐vinylformamide (APNVF), APNVF‐4 that had the highest charge density was the most effective for strengthening paper. The effectiveness of the retention systems increased with their wet functionality in the order APNVF‐4 > C‐PAM ≈ PAAm > PEI > PDADMAC. The curing temperature and curing time had little influence on paper dry strength, but they influenced paper wet strength greatly. The FTIR studies on model reactions showed that glycidyl groups could react with amino groups and carboxyl groups under common curing conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2791–2797, 2001     

Effects of heat treatment on tensile properties of high‐strength poly(vinyl alcohol) fibers

The tensile properties of high‐strength poly(vinyl alcohol) (PVA) fibers after heat treatment in air, water, and engine oil were studied. The results show that heat treatment in air, water, and engine oil have a different influence on the tensile properties of high‐strength PVA fibers. After heat treatment in air, the fibers possess excellent heat stability of the tensile properties. But in water, especially in hot water, the tenacity, Young's modulus, and specific work of rupture of the fibers decrease, while the elongation at break of the fibers increases. Similarly, engine oil has a significant influence on the tensile properties of the fibers. When the temperature of engine oil is above 120°C, the tensile properties of the fibers decrease drastically. We also discuss the influence of heat, water, and engine oil on the tensile properties of high‐strength PVA fibers in relation to the structure of the fibers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 237–242, 2000     

Effects of modified poly(methacrylic acid) copolymer on rheological properties of ceramic suspension and sintered ceramic strength

Modified waterborne poly(methacrylic acid) (MPBMA) with hydrophilic and hydrophobic groups is prepared by reacting maleic anhydride/polyglycol, α‐olefine benzenesulfone, and methyl methacrylate. Using MPBMA as a ceramic dispersant, the effects of the MPBMA concentration on the rheological behavior of a ceramic suspension and the ceramic breaking strength are studied, and the reasons and its dispersing mechanism are analyzed. The results show that MPBMA can improve the suspension's rheological properties and enhance the ceramic strength. The optimum copolymer concentration is 0.20 wt % at pH 9–10. When adding 0.20 wt % MPBMA, the suspension's absolute ζ potential increases from 23.7 to 64.2 mV, and its zero shear viscosity decreases from 714.3 to 73.4 mPa s. At the same time, its thixotropy area reaches the minimum, and the suspension exhibits Newton flow behavior and good dispersivity. Compared with inorganic dispersant, the ceramic with added MPBMA has higher breaking strength, which is increased from 160 to 352 MPa. Scanning electron microscopy photographs show that the flocculate of particles is disintegrated and the particles scatter mutually. They also show that no aggregation phenomenon appears in the ceramic with MPBMA added and the pores distribute uniformly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2661–2667, 2006     

Synthesis,characterizations, and mechanical properties of structurally modified poly(vinyl alcohol)

Poly(vinyl alcohol) (PVA) was structurally modified with two different types of chemicals under nitrogen atmosphere in the presence of Sb₂O₃ as a catalyst at 80°C in an aqueous medium. An FTIR and NMR spectrum confirmed the structural modification of PVA. DSC and TGA counseled the thermal properties of structurally modified PVA. Urea modified PVA exhibited higher mechanical strength than the pristine PVA. The FTIR‐relative intensities of olefin formation and ketone formation were increased with the increase of weight of water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010