吸水膨胀橡胶的研究进展

介绍了吸水膨胀橡胶的吸水膨胀机理、基体材料选择、制备工艺以及近年来的研究发展概况,并对吸水膨胀橡胶制备中存在的问题进行总结。吸水膨胀橡胶主要由橡胶基体和亲水组分组成,采用物理共混和化学接枝的方法制备,吸水后亲水组分析出、吸水膨胀倍率和吸水膨胀速率的选择、橡胶交联密度与吸水倍率的平衡等问题是吸水膨胀橡胶在实际应用中普遍存在的问题,需重点研究。     

吸水膨胀橡胶性能的改进

吸水膨胀橡胶性能比较吸水膨胀橡胶能吸收自重几倍甚至几十倍以上的水，并在一定压力下水不会渗出，从而起到良好的水密封作用。这种橡胶在建筑工程中作为止水剂、填缝剂及密封剂，在国外已获得广泛应用，其效果显著。国内近些年已有不少单位研制并生产这种橡胶。吸水膨胀橡胶一般是在橡胶中加入吸水性树脂制成，但此时制成的吸水膨胀橡胶膨胀率低，止水性能差，而膨胀率太大时，橡胶强度极低，易崩裂，难以达到理想的密封效果。针对上述情况，日本三洋化成公司最近研制开发出一种新型吸水膨胀橡胶胶料。该胶料主要特征是在吸水膨胀胶料中，…     

一种提高吸水膨胀橡胶性能的方法

由沈阳化工大学申请的专利(公开号CN101983980A,公开日期2011-03-09)"一种提高吸水膨胀橡胶性能的方法",提供了一种提高吸水膨胀橡胶性能的方法,即将介孔分子筛与吸水膨胀橡胶按100∶(0.1～10)质量比混合,使介孔分子筛均匀分散于吸水膨胀橡胶基体中,制得吸水膨胀橡胶复合材料。其中介孔分子筛分为无孔道和有孔道结构,形状以规则球形为主,平均粒径为80～100nm;吸水膨胀橡胶是在橡胶基体中引入     

遇水膨胀橡胶的吸水膨胀和力学性能研究

以天然橡胶和吸水树脂（聚丙烯酸钠）为主要原料，以含聚氧化乙烯嵌段的亲水亲油型多嵌段共聚物为增容剂，活性陶土为补强剂，利用多组分机械共混技术，制备了遇水膨胀橡胶，从吸水动力学数据出发，研究了重量吸水率与增容剂含量，吸水树脂含量之间的关系；对遇水膨胀橡胶吸水前后的力学性能进行了测试。结果表明，增容剂的加入能显著改变遇水膨胀橡胶的吸水性能和力学性能。     

共混型吸水膨胀橡胶增容剂的研究进展

在共混型吸水膨胀橡胶（WSR）中添加适当的增容剂,可以提高WSR中弹性体与亲水性组分的微观相容性,进而提高WSR吸水膨胀性能、力学性能及耐用性等应用性能。本文介绍了共混型吸水膨胀橡胶增容剂的国内外研究现状。     

多嵌段共聚物增容的遇水膨胀橡胶研究

以天然橡胶和吸水树脂（聚丙烯酸钠）为主要原料，以含聚氧化乙烯嵌段的亲水亲油型多嵌段共聚物为增容剂，以活性陶土为补强剂，利用多组分机械共混技术，制备了遇水膨胀橡胶；从吸水动力学数据出发，研究了重量吸水率与增容剂含量、吸水树脂含量之间的关系；对遇水膨胀橡胶吸水前后的力学性能进行了测试。结果表明，增容剂的加入能显著改变遇水膨胀橡胶的吸水性能和力学性能。     

共混型吸水膨胀橡胶的配方优化设计

对天然橡胶(NR)／丁苯橡胶(SBR)胶料应用正交试验法和丁腈橡胶(NBR)胶料用回归分析法对制备吸水膨胀橡胶的吸水膨胀性和物理机械性能进行研究。结果表明：吸水膨胀橡胶的吸水膨胀率随吸水树脂用量增加而增大，拉伸强度和扯断伸长率随吸水树脂用量增加而降低；硫化剂用量越多橡胶吸水膨胀率越小：补强剂采用白炭黑日寸有利于提高胶料的吸水膨胀率，而采用炭黑补强日寸则物性有所提高，但吸水膨胀率却明显下降。     

原位合成丙烯酸盐改性氯化聚乙烯制备吸水膨胀橡胶的研究

通过金属氢氧化物(或氧化物)和丙烯酸(AA)的中和反应，在氯化聚乙烯(CPE)中原位合成丙烯酸盐(MeAA)，加入DCP硫化后得到吸水膨胀橡胶。研究吸水膨胀橡胶制备过程中的化学反应以及混炼胶的硫化特性和硫化胶的吸水膨胀性能及物理性能。结果表明，原位合成MeAA改性的CPE具有良好的物理性能和吸水膨胀性能，一价金属盐硫化胶的吸水膨胀性能比二价金属盐更为优异。     

聚氨酯树脂/丁腈橡胶接枝型吸水膨胀橡胶的性能

研究聚氨酯(PU)树脂/丁腈橡胶接枝型吸水膨胀橡胶的性能。结果表明,随着吸水树脂中PU含量的增大,吸水膨胀橡胶的物理性能提高,最大质量吸水率增大;当PU完全替代聚丙烯酸钠时,随着DCP用量的增大,吸水膨胀橡胶的综合物理性能下降,质量吸水率减小,当DCP用量为2份时,吸水膨胀橡胶的最大质量吸水率保持在2.04倍以上,重复吸水质量保持率保持在98%以上。     

吸水膨胀橡胶

橡胶本身是疏水性材料，但配入亲水性大的物质可以增加它的吸水性，橡胶中添加超吸水性树脂，可以得到遇水后体积膨胀高达４－６倍吸水性橡胶制品，也可通过橡胶与聚环氧乙烯接枝制备吸水膨胀橡胶。吸水膨胀橡胶广泛用于建筑和地下管道的防水工程。     

Soil mechanics of the potentially expansive clays in Poland

This paper is an attempt to evaluate the expansivity of the main genetic types of Polish clays which very often are considered as a bedground for engineering structures. Lithological characteristics and basic physical properties presented in this paper concern the soils of (I) Quaternary age: Boulder clays and glaciolacustrine clays, (II) Tertiary continental and marine clays: Mio-Pliocene clays of Poznan series, Miocene clays of the Carpathian Foredeep (unweathered and weathered), bentonites and bentonitic clays, oligocene clays of Szczecin area and Carboniferous bentonites (Tables 1 and 2). Based on the indirect methods described by Van der Merwe (1964) and Seed et al. (1962) nomograms were used to evaluate potentially expansive soils. Information obtained includes correlation between potential expansiveness (PE), degree of expansion (DE), swelling potential (5) and the percentage content and mineral composition of the clay fraction. Graphic illustrations are presented in Figs. 1–7, which also include nomograms for the approximate estimation of the value of swell pressure (σ_sp). The evaluation of potential expansivity of clays in Poland plays a key role in the design of engineering structures and in site selection.     

Changes in the cross-link density of Goynuk oil shale (Turkey) on pyrolysis

The effect of temperature and heating rate on the cross-link density of char samples obtained by pyrolysing Goynuk oil shale was investigated using the volumetric solvent swelling technique. The cross-link density decreases slightly with increasing pyrolysis temperature. The heating rate and thus the pyrolysis time had at most a small effect on the cross-link density. Char-solvent interactions do not follow regular solution theory. The demineralized kerogen swells more than does the native kerogen (16% ash).     

超高分子量聚乙烯树脂的溶胀性的检测分析

通过上海化工研究院设计的在线检测装置对超高分子量聚乙烯(UHMWPE)溶胀过程中的温度、黏度进行测试,形成了UHMWPE树脂溶胀工艺的检测方法,对黏均分子量分别为3.261×106(A),3.833×106(B),3.455×106(C)3种不同树脂的溶胀温度、溶胀时间、溶胀比等参数进行了分析。结果表明:A,B,C树脂的溶胀温度分别为121,120,119℃;对溶胀釜加热系统设定统一温度,釜内温度达120℃时,A,B,C树脂的溶胀时间分别为60,30,3 min,溶胀比分别为2.37,2.51,2.31。     

依兰煤在液化溶剂中的溶胀动力学研究

笔者以依兰煤为原料,研究了依兰煤在室温至2000℃范围内在液化起始溶剂和循环溶剂中的溶胀行为,并确定了依兰煤在试验条件下的溶胀动力学参数。试验结果表明：依兰煤在液化起始溶剂和循环溶剂中的溶胀度随溶胀温度的增加和溶胀时间的延长而增大;依兰煤在这2种溶剂中的溶胀都是受Case-Ⅰ扩散控制为主的过程,其溶胀活化能分别为4．18和4．22kJ·mol^-1。     

Experimental assessment of the utilization of a novel interpenetrating polymer network in different processes in the agricultural sector

We synthesized a biodegradable, controlled release formulation via the impregnation of methyl methacrylic acid onto the natural polysaccharide, gum tragacanth, and a polyacrlyic-based hydrogel with glutaraldehyde as crosslinker. The biodegradation behavior of the prepared interpenetrating polymer network (IPN) was investigated with soil burial and composting methods, and the biodegradability stages were studied with Fourier transform infrared spectroscopy and scanning electron microscopy analyses. The controlled release data of the calcium nitrate was analyzed in accordance with Fick's power law, and the kinetics parameters of the release process were calculated. The values of the initial and lateral diffusion coefficients indicated a fast initial release rate of the fertilizers in comparison to the lateral release. The synthesized IPN was degraded 91.62% within 11 weeks under composting methods, whereas it degraded 78.83% under the soil burial method. The results show that the synthesized IPN was ecofriendly and could be used for the controlled release of agrochemicals. The impact of the degraded IPN on the fertility of the soil was also studied. We concluded from the results obtained that the biodegraded IPN did not have any adverse effects on the soil fertility. Hence, this biodegradable IPN could be of great significance from a green revolution point of view. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47739.     

Investigating the reduction in the absorption intensity of P3HT in polymer/fullerene “bilayers” coated using orthogonal solvents

We investigated the reduction in the absorption intensity of poly(3‐hexylthiophene) (P3HT) in a poly(3‐hexylthiophene)/(6,6)‐phenyl‐C₆₁‐butyric acid methyl ester (P3HT/PCBM) “bilayer” heterojunction film that was fabricated using orthogonal solvents. The results show that even though P3HT is insoluble in dichloromethane (DCM), DCM could decrease the chain packing and the crystallinity of the P3HT film by the swelling effect. DCM also assists in the penetration of the PCBM into the P3HT underlayer during spin‐coating. After the DCM evaporates, the PCBM in the P3HT matrix hinders the self‐reorganization of P3HT, causing a drop in the absorption intensity of P3HT. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41757.     

Influence of swelling solutions on the behavior of cholesteric networks

The swelling behavior of an ethyl‐cyanoethyl cellulose/crosslinked poly(acrylic acid) cholesteric network in different swelling solutions was studied. The swelling behavior of the cholesteric network was reversible in acid or neutral solutions and was irreversible in basic solutions. The cholesteric network retained the cholesteric structure during the swelling process in NaCl aqueous solutions, and the swelling behavior was incompletely reversible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 724–729, 2005     

Quantifying the swelling properties of alkali‐silica reaction (ASR) gels as a function of their composition

Synthetic alkali‐silica reaction (ASR) gels were produced and tested to investigate the effects of chemical composition (Ca/Si, Na/Si, and K/Si atomic ratios) on the gels’ free swelling strain (ε_g,fr) and restrained swelling pressure (P_rs). The gels were cast into disk‐shape molds and exposed to distilled water after curing. Each gel's ε_g,fr was recorded over a period of 28 days, followed by measuring P_rs, defined as the pressure required to fully reverse and eliminate the gel's free swelling under a drained configuration. Regression models were developed linking gels compositions to their swelling properties. The outcomes show that Na/Si and K/Si monotonically increase ε_g,fr. Increasing Ca/Si up to 0.23 drastically reduces ε_g,fr; higher Ca/Si has modest effect on free swelling. P_rs increases by increasing calcium up to a pessimum Ca/Si level; P_rs decreases for higher Ca/Si. The value of (Ca/Si)_pess is related to the alkali content of the gel. P_rs also increases by increasing the gel's alkali content, while a (Na/Si)_pess exists in the range 0.85‐0.95. These observations are linked with the roles of alkalis and calcium in modifying the silica gel network.     

Determination of the kinetics of diffusion in coals by solvent swelling techniques

A simple technique has been developed for measuring the kinetics of solvent diffusion in coals at various temperatures. The technique is based on a well-known method for measuring the volumetric swelling of coals by solvents. Several coals have been examined in both pyridine and tetrahydrofuran, at temperatures between 298 and 332 K. The diffusion follows the well-established case II rate law at ambient temperatures, implying that the processes are controlled by relaxation in the coal network structure. As temperatures are increased, the process becomes more Fickian in nature. The activation energies for the diffusion-relaxation processes are in the range 31 to 82 kJ mol⁻¹.     

吸水膨胀材料的研究进展和应用前景

论述了吸水膨胀材料的研究进展和应用前景以及生产现状,并对其市场进行了分析和预测,建议利用我省的科研和原料优势,忙使其实现产业化,以推动我省复合材料产业的发展。