论文总字数：24173字

摘 要

ASA是丙烯腈-苯乙烯-丙烯酸酯的三元接枝共聚物，具有核壳结构，是一种应用广泛的工程塑料。为了拓宽其应用范围，必须对其进行改性以提高其耐热性。选用α-甲基苯乙烯丙烯腈(α-MSAN)与ASA熔融共混进行耐热改性。α-MSAN具有位阻效应极大的苯环和甲基，并带有强极性的氰基。α-MSAN的加入虽极大地改善了ASA的耐热性能，但也导致了其韧性的下降。因此，便出现了对ASA/α-MSAN进行增韧的研究。热塑性聚氨酯弹性体(TPU)具有较好的韧性、耐低温、和加工性能，同时具有极性，与ASA/α-MSAN相容性较好。因此本实验选取TPU作为增韧剂进行增韧。首先选取不同种类的TPU，通过熔融共混的方法制备ASA/α-MSAN/TPU(25/75/15)三元共混物，找出增韧效果最佳的TPU作为增韧剂。随后研究该种TPU加入量变化对共混物性能的影响(0-30phr)，并重点研究了共混物在低温时的冲击性能。

本实验利用冲击试验机、电子万能试验机、红外光谱仪(FTIR)、示差扫描量热法(DSC)等仪器对共混物的力学性能、组分之间相互作用、相容性以及玻璃化转变温度等进行了测试与表征。结果表明：在所有备选的TPU中，聚酯型TPU(邵氏硬度80A)的增韧效果最好，与未增韧ASA/α-MSAN相比，冲击强度由5.4kJ/m²提升至10.7kJ/m² (TPU加入量15 phr)，提高了接近2倍，断裂伸长率为也明显提升。但拉伸强度与耐热性能有所降低。

选取TPU(邵氏硬度80A)为增韧剂，对ASA/α-MSAN/TPU中TPU变量进行研究，常温冲击表明：随着TPU加入份数的增加，冲击性能变好。当TPU加入量为30phr时，冲击强度为26.5kJ/m²，是未增韧时ASA/α-MSAN的5倍。当聚酯型TPU(80A)加入量从15phr增加到20phr时，冲击强度由12.6kJ/m²提升至22.3kJ/m²，产生较明显的脆韧转变。低温冲击结果表明：在0^oC下TPU加入量为30phr时共混物还具有较好的韧性，冲击强度保持在18.7kJ/m²；但是在-30^oC下，TPU的加入对冲击性能提升作用很小。DSC结果表明：在-30^oC左右是TPU软段的玻璃化转变温度(T_g)，解释了TPU在-30^oC增韧效果不佳的原因。FTIR结果表明：加入TPU后ASA/α-MSAN的特征峰位置没有发生明显的偏移，说明TPU的加入只是一个简单的物理共混过程，并且没有形成特殊的分子间作用。

关键词： ASA TPU α-MSAN 共混 增韧 力学性能

Study on toughening modification of ASA-60/α-MSAN/TPU blends system

Abstract

ASA is a kind of copolymer of acrylonitrile-styrene-acrylate, which has a core-shell structure and is a widely used engineering plastics. In order to broaden its application range, it is necessary to improve its heat resistance. α-methyl styrene acrylonitrile (α-MSAN) was chosen to enhance heat resistance of ASA via melt blending. The benzene and methyl of α-MSAN have great steric effect and the cyano has strong polarity. The addition of α-MSAN greatly improved the heat resistance of ASA, but resulted in the decrease of its toughness. Therefore, the research on the toughening of ASA/α-MSAN was carried out. Thermoplastic polyurethane elastomer (TPU) has many good properties, such as good toughness, low temperature resistance, and easily processing performance, so TPU was chosen for toughening ASA/α-MSAN blends. Firstly, the ASA/α-MSAN/TPU (25/75/15) ternary blends were prepared by melt blending, and the TPU with best toughening effect was chosen as toughening material for further investigation. Then the effect of composition of ASA/α-MSAN/TPU blends was studied, and the impact strength of the blends at low temperature was mainly focused.

In the experiment, Izod impact tester, electronic universal testing machine, fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) were used to characterize the mechanical properties, compatibility and glass transition temperature. The results showed that in all the alternative TPU, polyester (shoreA hardness 80A) TPU has best toughening effect. Compared with ASA/α-MSAN without toughening, impact strength increased from 5.4kJ/m² to 10.7kJ/m² (with addition of 15 phr TPU). The elongation at break improved significantly. But the tensile strength, bending modulus, bending strength and heat resistance decreased.

The effect of TPU content in ASA/α-MSAN/TPU blends was investigated. The impact strength showed that the toughness of blends became better with the addition of TPU. When the addition of TPU was 30phr, the impact strength was 26.5kJ/m², which was 5 times of the non-toughened ASA/α-MSAN. When the addition of polyester TPU (80A) increased from 15phr to 20phr, the impact strength increased from 12.6kJ/m² to 22.3kJ/m², resulting in an obvious brittle ductile transition. The results showed blends with addition of 30phr TPU remained good toughness at 0^oC, and the impact strength was 18.7kJ/m². However, under the -30^oC, the impact of the addition of TPU is very small. DSC results show that the glass transition temperature (T_g) of the TPU is about -30^oC, which explains the reasons for the poor toughness of TPU at -30^oC. The results of FTIR spectra showed with the addition of TPU, characteristic peaks of ASA/ α-MSAN exhibited no obvious shift, which meant the blending process was just a simple physical blending process, and there exist no special molecular interaction in blends.

Keywords: TPU ASA α-MSAN blends toughness mechanical properties

目 录

摘 要 I

ABSTRACT II

第一章 前言 1

1.1 课题背景 1

1.2 国内外进展 2

1.3 本文的工作 3

第二章 理论部分 4

2.1 ASA树脂简介 4

2.1.1 ASA树脂起源 4

2.1.2 ASA的制备工艺 5

2.1.3 ASA树脂的性能 5

2.1.4 ASA树脂的市场与应用 5

2.2 ASA的耐热改性研究 7

2.2.1 α-MSAN的耐热性研究 7

2.2.2 ASA/α-MSAN共混改性研究 7

2.3 TPU/ASA-60/α-MSAN的增韧研究 8

2.3.1 TPU的增韧研究 8

2.3.2 TPU/ASA-60/α-MSAN增韧研究 9

第三章 实验部分 11

3.1 实验原料： 11

3.2 实验仪器与设备 11

3.3 实验配方 11

3.4 样品制备 12

3.4.1 熔融共混 12

3.4.2 压片成型 12

3.4.3 试样制备 12

3.5 测试与表征 13

3.5.1 傅里叶变换红外光谱分析 13

3.5.2 力学性能测试 13

第四章 结果与讨论 14

4.1不同类型TPU增韧ASA-60/α-MSAN 14

4.1.1 冲击试验 14

4.1.2 拉伸试验和弯曲试验 15

4.2不同份数聚酯型TPU(80A)增韧ASA-60/α-MSAN 16

4.2.2 拉伸试验和弯曲试验 18

4.2.3 热变形温度实验 20

4.2.4 傅里叶变换红外光谱分析 21

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