论文总字数：19057字

摘 要

工业生产过程中，水垢的形成给生产带来的一系列的问题。同其他除垢方法相比较，添加阻垢剂因其添加量少且处理量大，更加适合处理工业水的结垢问题。然而随着工业的发展，人们对环境的保护意识越来越深，对工业废水的排放要求也越来越严格，因此，开发阻垢效率高，对环境友好的阻垢剂是今后阻垢剂优先发展的方向。

本文阐述了合成及改性超支化聚酯的过程、通过不同的表征方法分析其化学结构，并通过对硫酸钙的阻垢实验来进行考察其阻垢性能。合成实验中，以2,2-二羟甲基丙酸（DMPA）和三羟甲基丙烷（TMP）作为原料，摩尔质量为9：1，在对甲苯磺酸的催化作用下，缩聚合成第二代端羟基超支化聚酯（HBPE-2-OH），探究方法采用单因素法，对于不同合成温度与合成时间进行考察，对产品进行核磁表征与红外表征，分析其化学结构。改性实验中，将合成的HBPE-2-OH与丁二酸酐作为原料，在4-二甲氨基吡啶催化作用下改性为端羧基超支化聚酯（HBPE-2-COOH），对HBPE-2-COOH进行红外表征，分析其化学结构，并与HBPE-2-OH的红外图作比较，然后利用硫酸钙用静态阻垢实验法对端羧基超支化聚酯进行阻垢性能的探究，将垢样晶体添加阻垢剂前后进行表征。

在本实验中，合成实验中根据羟值与收率值，确定端羟基超支化聚酯合成温度为140℃，再于140℃恒温下确定合成时间为4 h。在改性实验中，通过红外光谱图与核磁氢谱图分析得出，具有超支化结构的端羧基超支化聚酯被成功制取。得到的端羧基超支化阻垢剂在通过阻垢实验，得出合成温度在140℃时合成时间4 h，改性后对CaSO₄的阻垢率可达97％。通表过SEM对比分析，具有超支化结构的阻垢剂使硫酸钙晶体垢质变得疏松，起到了阻垢作用。

关键词：超支化聚酯；阻垢剂；硫酸钙

Research on Modification of Hyperbranched Polyester and Its Scale Inhibiting Performance

ABSTRACT

In the industrial production process, the formation of scale brings a series of problems to production.As with other methods of descaling and scale inhibition, the addition of the scale inhibitor is more suitable for treating the scaling problem of industrial water because of its small addition amount and large treatment amount.However, with the development of industry, people's awareness of environmental protection is getting deeper and deeper, and the requirements for industry are becoming more and more strict. Therefore, the development of high scale and efficiency, environmentally friendly and scale inhibitors is the future direction of the priority development of inhibitors.

In this paper, the synthesis process, modification process, characterization method and scale inhibition performance of hyperbranched polyester were described. Analysis of the hyperbranched structure inhibitors of calcium sulfate scale inhibition. Using 2,2-dimethylolpropionic acid as monomer and trimethylolpropane as the core, it is polycondensed into a terminal hydroxyl hyperbranched polyester under the action of p-toluenesulfonic acid. The single factor method is used for different synthesis temperatures and synthesis. The reaction conditions of time were investigated. The synthesized hydroxyl terminated hyperbranched polyester was characterized by nuclear magnetic characterization and infrared characterization, and then modified by the synthesis of terminal hydroxyl hyperbranched polyester and succinic anhydride under the catalysis of 4-dimethylaminopyridine. The terminal carboxyl hyperbranched polyester is characterized by infrared characterization of the modified terminal carboxyl hyperbranched polyester, compared with the infrared image of the terminal hydroxyl hyperbranched polyester, and then the calcium carboxylate is super-branched by the static scale inhibition experiment. The ester was investigated for its scale inhibition performance, and the scale-like crystals were characterized before and after the addition of the scale inhibitor.

In this experiment, in the synthesis experiment, according to the hydroxyl value and the yield value, the synthesis temperature of the terminal hydroxyl hyperbranched polyester was determined to be 140℃, and the synthesis time was determined to be 4 h at a constant temperature of 140℃. In the modification experiment, the end-carboxy hyperbranched polyester with hyperbranched structure was successfully prepared by infrared spectrum and nuclear magnetic resonance spectrum analysis. The obtained terminal carboxyl hyperbranched scale inhibitor passed the scale inhibition experiment, and the synthesis time was 4h at 140℃, and the scale inhibition rate of CaSO4 after modification was 97%. Through the SEM comparative analysis, the scale inhibitor with hyperbranched structure makes the calcium sulfate crystal scale loose, which plays a role in scale inhibition.

Key words: hyperbranched polyester；scale inhibitor；calcium sulfate

目录

摘要 I

ABSTRACT II

第一章 文献综述 1

1.1课题背景 1

1.2结垢机理及阻垢除垢方法 1

1.2.1结垢机理 1

1.2.2阻垢除垢方法 1

1.3阻垢剂的分类 2

1.4阻垢机理及阻垢性能评定 4

1.4.1阻垢机理 4

1.4.2阻垢性能评定 5

1.5超支化聚酯 6

1.5.1超支化聚酯的合成 7

1.5.2超支化聚酯的改性 7

1.6本课题研究意义和主要研究内容 8

第二章 实验部分 10

2.1实验仪器及试剂 10

2.2实验过程 11

2.2.1端羟基超支化聚酯的合成 11

2.2.2端羟基超支化聚酯的改性 11

2.2.3性能测试及表征方法 11

第三章 结果与讨论 14

3.1合成温度对端羟基超支化聚酯的影响 14

3.2合成时间对端羟基超支化聚酯的影响 14

3.3端羟基超支化聚酯合成及改性表征 15

3.4端羧基超支化聚酯阻垢性能考察 17

3.5端羧基超支化聚酯对硫酸钙晶体的影响 19

第四章 结论 21

参考文献 22

致谢 25

第一章 文献综述

1.1课题背景

现如今，在冷却水循环、油田生产、膜应用等过程中，由于阴阳离子的富集浓缩，极易导致难溶性盐在设备表面出现沉淀^[1]，形成水垢。而水垢的产生容易增加能耗，会堵塞输送管路，降低生产效率，腐蚀破坏设备，造成一些不必要的安全事故^[2]。因此，各国企业每年都会花费大量资金定期清理水垢或处理结垢带来的问题。阻垢剂作为一种控制系统结垢的手段，具有用量少，效果好等优点，且是处理水垢最有效的方法之一。从上个世纪40年代问世以来，深受行业青睐。

1.2结垢机理及阻垢除垢方法

1.2.1结垢机理

晶体成长理论通常认为，一般水溶液中的难溶盐从溶液达到饱和平衡状态，形成固体沉淀的过程中包含了一个过饱和阶段，而产生固体沉淀的必要条件是，溶液中难溶盐离子浓度达到一定的过饱和度^[3]。在各类水体中，各类矿物质盐一般以螯合物状态或阴阳离子稳定存在。而在设备表面附近，因为水体会因为温度的变化，而导致PH值变化、溶解度变化等使得盐溶液极易出现过饱和状态，所以出现早期成核现象，而沉积物会因为晶核的生长膨胀而形成^[4,5]。

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