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毕业论文网 > 毕业论文 > 材料类 > 复合材料与工程 > 正文

有机硅改性苯丙乳液的制备及性能研究毕业论文

 2020-02-19 03:02  

摘 要

涂料在工业生产和人们的日常生活中应用日益广泛,由此引起的空气污染现象也日益严重,一些涂料中的挥发性物质挥发到空气中对人体造成的损害极大,已经引起了人们极大的重视。它们不但损伤皮肤,还会对人体的各身体系统的新陈代谢有破坏作用。因此,社会对涂料的性能要求也不断提高。水溶性涂料,被称作环境友好型涂料,因其以水为介质,挥发时间长,可以大量减少了有毒挥发物的产生,并且成本较低而被广泛应用,而苯丙乳液也因为由于具有成膜性好,高性价比等优点成为了首选的涂料主要成膜物质。

苯丙乳液中和了软单体丙烯酸酯类良好的柔韧性以及硬单体的耐磨性,经共聚制得。用途广,经济实用,在涂料,油墨,粘合剂中均得到了广泛的应用。广泛的通用性和较之其他材料相对低廉的价格,使它在国内外市场上广受欢迎。但是,它也存在耐水性差,耐氧化性差,对温度反应比较敏感的缺点,因此对其进行改性是改善其性能的重要研究方向。

本文在保持软单体丙烯酸正丁酯(BA)质量不变的情况下,选择苯乙烯(St)和甲基丙烯酸甲酯(MMA)两种硬单体,以Y-甲基丙烯酰氧基丙基三甲基硅烷(KH-570)和Y-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)为有机硅改性单体,SDS和OP-10混合液为乳化剂,经过过硫酸铵(APS)引发,通过半连续乳液聚合法合成了有机硅改性的苯丙乳液。通过改变单体的配比,确定性能最佳时的比例,通过改变有机硅的加入量,确定出合成有机硅改性苯丙乳液所需要的最优工艺条件。对产物进行宏观,微观性能测试。得出结论为:

(1)不加入有机硅改性单体,保证单体总质量36g,软单体BA质量20g不变,改变硬单体中St,MMA的比例,成功制备出了纯苯丙乳液。测试结果显示:当St:MMA=1:1时,乳液固含量为40.22%,转化率为98.84%,硬度为4B,附着力等级为4级,稳定性测试均良好,耐水性,耐化学试剂性,硬度,附着力测试相比其他配比性能更佳,为最佳比例。

(2)确定硬单体的比例为1:1后,保证总单体的量为36g不变,只加入一种改性单体KH-570,成功制备出了有机硅改性的苯丙乳液。改变硅烷偶联剂的含量,测试结果显示,当KH-570占单体总量4%时性能最佳。此时固含量为40.61%,转化率为99.78%,硬度为2B,附着力为2级,提高显著。稳定性,耐化学试剂性,耐水性均有提高,说明改性成功。

(3)确定KH-570含量为4%后,尝试再引入改性单体KH-560,同样保持总单体质量不变,测试结果显示,当KH-560,MAA(KH-560:MAA=1:4)共占比2%时测试性能最佳,此时,乳液固含量为40.36%,转化率为99.19%,耐水性,耐化学试剂性都继续提高,硬度达到H,附着力达到1级。

综合结果表明:有机硅改性单体的加入可以明显改善苯丙乳液的耐水性,耐化学试剂性,力学性能,加入两种有机硅改性单体后性能更加。

关键词:苯丙乳液;有机硅改性;乙烯基硅烷偶联剂;环氧基硅烷偶联剂

Abstract

Coatings are increasingly used in industrial production and people's daily life, and the resulting air pollution is also becoming more and more serious. The volatile substances in some coatings volatilize into the air and cause great damage to the human body, which has caused great people. Value. They not only damage the skin, but also destroy the metabolism of the body's various body systems. Therefore, society's performance requirements for coatings are also constantly increasing. Water-soluble paints, known as environmentally friendly coatings, are widely used because they use water as a medium and have a long volatilization time. They are widely used to reduce the generation of toxic volatiles, and are widely used because of their low cost. Good film forming properties, high cost performance and other advantages have become the preferred coating material for filming.

The styrene-acrylic emulsion neutralizes the good flexibility of the soft monomer acrylate and the abrasion resistance of the hard monomer, and is obtained by copolymerization. Widely used, economical and practical, it has been widely used in coatings, inks and adhesives. Wide versatility and relatively low prices compared to other materials make it popular in both domestic and foreign markets. However, it also has the disadvantages of poor water resistance, poor oxidation resistance, and sensitivity to temperature reaction. Therefore, modification is an important research direction to improve its performance.

In this paper, while maintaining the soft monomeric n-butyl acrylate quality, select two hard monomers, styrene and methyl methacrylate, toKH-570 and KH-560are silicone modified monomers, and the mixture of SDS and OP-10 is an emulsifier. Initiated by ammonium sulfate, a silicone-modified styrene-acrylic emulsion was synthesized by semi-continuous emulsion polymerization. By changing the ratio of the monomers, the ratio of the best performance was determined. By changing the amount of silicone added, the optimum process conditions for synthesizing the silicone modified styrene-acrylic emulsion were determined. The product was tested for macroscopic and microscopic properties. The conclusion is:

(1) The pure styrene-acrylic emulsion was successfully prepared without adding the silicone modified monomer to ensure the total mass of the monomer was 36g, the soft monomer BA was 20g, and the ratio of St and MMA in the hard monomer was changed. The test results show that when St:MMA=1:1, the emulsion solid content is 40.22%, the conversion rate is 98.84%, the hardness is 4B, the adhesion level is 4, the stability test is good,water resistance,chemical resistance The hardness,hardness,and adhesion tests are better than other ratios and are the best ratio.

(2) After determining the ratio of the hard monomer to 1:1, the amount of the total monomer was kept unchanged at 36 g, and only one modified monomer KH-570 was added, and the silicone-modified styrene-acrylic emulsion was successfully prepared. The content of the silane coupling agent was changed, and the test results showed that the performance was best when KH-570 accounted for 4% of the total monomer. At this time, the solid content was 40.61%, the conversion rate was 99.78%, the hardness was 2B, and the adhesion was 2, and the increase was remarkable. Stability, chemical resistance, and water resistance are all improved, indicating successful modification.

(3) After determining the KH-570 content of 4%, try to introduce the modified monomer KH-560, and keep the total monomer quality unchanged. The test results show that when KH-560, MAA (KH-560: MAA=1:4) The test performance is the best when the ratio is 2%. At this time, the solid content of the emulsion is 40.36%, the conversion rate is 99.19%, the water resistance and chemical resistance are continuously improved, the hardness reaches H, and the adhesion reaches 1 level.

The comprehensive results show that the addition of silicone modified monomer can significantly improve the water resistance, chemical resistance, mechanical properties of styrene-acrylic emulsion, and the performance after adding two kinds of silicone modified monomers.

Key Words:Styrene-acrylic emulsion;silicone modification;vinyl silane coupling agent;epoxy silane coupling agent

目 录

摘 要 I

目 录 1

第1章 绪论 3

1.1 前言 3

1.2 苯丙乳液的研究进展 3

1.3 有机硅改性的研究进展 4

1.4 本课题研究的背景和内容 4

1.4.1 研究背景 4

1.4.2 研究内容 5

第2章 苯丙乳液的制备 6

2.1 苯丙乳液的合成 6

2.1.1 苯丙乳液的合成原理 7

2.2 试验部分 7

2.2.1 试验原料 7

2.2.2 试验仪器设备 8

2.2.3 苯丙乳液的制备 8

2.3 测试与表征 10

2.3.1 乳液性能测试 10

2.3.2 涂膜性能测试 10

2.4 结果与分析 11

2.4.1 不同配比的硬单体对乳液聚合的影响 11

2.5 本章小结 12

第3章 有机硅KH-570改性苯丙乳液的制备 13

3.1 试验部分 14

3.1.1 试验原料 14

3.1.2 试验仪器设备 15

3.1.3 有机硅改性乳液的合成工艺 15

3.1.4 涂膜制备 16

3.2 测试与表征 16

3.2.1 乳液性能测试 16

3.2.2 涂膜性能测试 16

3.2.3 粒度分析 16

3.2.4 红外光谱分析 16

3.2.5 热重分析 16

3.3 结果与讨论 17

3.3.1 乳液性能分析 17

3.3.2 乳液的粒径分析 18

3.3.3 红外光谱分析 19

3.3.4 涂膜热重分析 19

3.4 本章小结 20

第4章 两种有机硅单体改性苯丙乳液的制备 22

4.1 试验部分 22

4.1.1 试验原料 22

4.1.2 试验仪器设备 23

4.1.3 两种有机硅单体改性乳液的合成工艺 23

4.1.4 涂膜制备 24

4.2 测试与表征 24

4.2.1乳液性能测试 24

4.2.2 涂膜性能测试 24

4.2.3 粒度分析 25

4.2.4 红外光谱分析 25

4.2.5 热重分析 25

4.3 结果与讨论 25

4.3.1 乳液粒径分析 27

4.3.2 红外光谱分析 27

4.3.3 热重分析 28

4.4 本章小结 29

第5章 结论与展望 30

5.1 结论 30

5.2 展望 31

致 谢 32

参考文献 33

第1章 绪论

1.1 前言

水性涂料的应用在我们的日常生活中随处可见,内外墙涂料,汽车表面的喷漆等都是水性涂料产品。由于聚合物的结构不同,水性涂料的种类有很多,而苯丙乳液是水性涂料中研究较多一种体系。

苯丙乳液是由苯乙烯和丙烯酸,甲基丙烯酸及其酯类单体经乳液聚合得到的的一种乳白色略带蓝光的乳液,是一种重要的中间化工产品。但是由于苯丙乳液存在高温呈粘稠状态,低温发脆的缺点,限制了它的应用。可以通过引入具备我们要求的特性的某些改性单体来改善其缺陷。有机硅改性,就是其中一种较为常用的改性方法。利用Si-O键能高、内聚能密度低、分子的体积较大等特点以及有机硅材料柔软性高、耐温和耐化学介质性好和成膜性好等优点,对涂层的性质进行优化。

1.2 苯丙乳液的研究进展

苯丙乳液是由苯乙烯和丙烯酸酯类单体经过乳液聚合的方法得到的,乳液呈乳白色,稍显蓝光,已成为当前涂料工业的主要研究方向。但是由于苯丙乳液的性能也存在一些缺陷:硬度低,附着力不高,吸水率高,耐水性差等,因此,选择合适的改性方法进行改性至关重要,如引入功能改性单体。根据生产的不同需要选择不同的单体,总体来说,根据单体自身的功能不同可分为硬单体,软单体和功能单体三大类。其中,丙烯酸乙酯(EA),丙烯酸正丁酯(BA),丙烯酸异辛酯(2-EHA),是实验中经常使用的的软单体;甲基丙烯酸甲酯(MMA),苯乙烯(St),丙烯腈(AN)则是经常选用的的硬单体。软硬单体配比不同,可以获得不同Tg的丙烯酸涂膜。

表1-1 常见的功能单体在苯丙乳液中的作用

单体名称

功能

丙烯酸正丁酯

改善柔韧性,促进成膜,称之为软单体

苯乙烯

提高硬度,抗污染性,成膜性,称之为硬单体

甲基丙烯酸甲酯

提高硬度,称之为硬单体

甲基丙烯酸

増溶,增加附着力,称之为水溶性单体,表面活性单体

功能单体

改善苯丙乳液的耐水性,耐低温性

1.3 有机硅改性的研究进展

目前,有机硅改性苯丙乳液因具有优良的耐候性,耐热性和耐水性而成为建筑物外墙涂料首选之一,在木器,塑料,金属等基材上也同样前景大好。这是由于引入的Si-O的键长较长,键能也远大于C-O,C-C键,稳定性增强。改性苯丙乳液时,有机硅与其他单体或者聚合物共聚形成Si-O-Si键,在交联作用下,转变为体型网状结构,空间更加致密,耐热性,耐水性加强,从而达到改性的目的。在木材领域,普通木器涂料遇热发白,进行有机硅改性后可以很好的克服这个缺点,合成了一种兼具耐水,耐热,耐污多种优点的涂料。在电子领域,有机硅改性树脂可以用作电子元器件的保护涂层或密封胶。随着水性化技术的发展和有机硅改性技术的应用更加广泛,在更加尖端的领域,利用有机硅类化合物进行改性也将越发普遍。

1.4 本课题研究的背景和内容

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