本文選題：回收萘　切入點(diǎn)：萘系高效減水劑合成　出處：《重慶師范大學(xué)》2017年碩士論文

【摘要】：萘系高效減水劑是我國(guó)最早使用的高效減水劑,具有較好的減水效果,合適的引氣量,并且不會(huì)影響混凝土凝結(jié)時(shí)間,能顯著提高混凝土的機(jī)械性能,依然占據(jù)著較大部分市場(chǎng)。萘系高減水劑低成本優(yōu)化生產(chǎn)可以綜合利用有限的資源,將原料最大化利用也符合綠色化學(xué)的概念,更是降低生產(chǎn)成本有效方式。論文用部分回收萘代替工業(yè)萘,探討了萘系高效減水劑合成工藝,研究了萘系高效減水劑的性能。研究結(jié)果主要分為以下幾方面:(1)基于現(xiàn)代生產(chǎn)工藝合成并優(yōu)化萘系高效減水劑的工藝,得出了萘與硫酸最佳物質(zhì)的量比為1:1.4;磺化的溫度160~165℃;萘與甲醛物質(zhì)的量之比1:1.1;縮合反應(yīng)最佳酸度為29.5%;縮合反應(yīng)時(shí)間為4 h;(2)基于優(yōu)化的萘系高效減水劑的合成工藝,用部分回收萘替代工業(yè)萘合成萘系高效減水劑;并分析了添加回收萘對(duì)合成萘系高效減水劑的影響。實(shí)驗(yàn)了回收萘不同添加量下萘與硫酸物質(zhì)的量之比,萘與甲醛物質(zhì)的量之比,反應(yīng)溫度等因素對(duì)減水劑性能的影響,得出了在回收萘的摻量為5%的情況下、萘與硫酸的物質(zhì)的量之比為1:1.4、萘與甲醛的物質(zhì)的量之比為1:1、縮合時(shí)間為4 h。通過(guò)凈漿流動(dòng)度和膠砂流動(dòng)度測(cè)試了新產(chǎn)品作用于水泥的性能,得出水泥凈漿和膠砂的流動(dòng)度在240 cm到250 cm。并通過(guò)紫外吸光光度法測(cè)試了減水劑在水泥顆粒表面的最大吸附量對(duì)應(yīng)的最佳摻量為水泥質(zhì)量的1%,測(cè)試了產(chǎn)品作用于水泥漿的Zeta電位值分別為-45.7、-47.8、-47.7、-48.3 mV,驗(yàn)證了產(chǎn)品作用于水泥漿較強(qiáng)的分散性。(3)在綜合分析了引起水泥凈漿流動(dòng)度損失快的機(jī)理之后,提出改良思路用氨水、尿素等低成本的無(wú)機(jī)弱堿溶液代替部分強(qiáng)堿溶液中和產(chǎn)品母液,得出水泥凈漿流動(dòng)度為256 cm和30 min后凈漿流動(dòng)度保持值200 cm,對(duì)比強(qiáng)堿中和的減水劑產(chǎn)品水泥凈漿流動(dòng)度為246cm和30 min后凈漿流動(dòng)度保持值185 cm均有明顯改善。綜上所述,控制回收萘添加量在5%以內(nèi)基本上不影響產(chǎn)品性能,并且在一定程度上降低了生產(chǎn)成本,達(dá)到了資源的綜合利用;采用氫氧化鈉強(qiáng)堿溶液和尿素中和減水劑母液可明顯增強(qiáng)水泥凈漿流動(dòng)度和流動(dòng)度保持性。
[Abstract]:Naphthalene superplasticizer is the first high efficiency water reducing agent used in China. It has better water reducing effect, suitable air entrainment rate, and will not affect the setting time of concrete, so the mechanical properties of concrete can be improved significantly. Naphthalene series high water reducer and low cost optimization production can make comprehensive use of limited resources and maximize the use of raw materials is also in line with the concept of green chemistry. In this paper, partial recovery of naphthalene instead of industrial naphthalene is introduced, and the synthetic process of naphthalene superplasticizer is discussed. The properties of naphthalene series superplasticizer were studied. The results were divided into the following aspects: 1: 1) based on the modern production process, the optimum ratio of naphthalene to sulfuric acid was 1: 1.4, the sulfonation temperature was 1600.165 鈩，

本文編號(hào)：1677051