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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

AIBNABVN复合二步发泡法制备低密度不饱和树脂材料毕业论文

 2022-07-05 22:44:24  

论文总字数:35206字

摘 要

I

Abstract II

第一章 文献综述 1

1.1 研究背景及意义 1

1.2 聚合物泡沫分类及应用 1

1.2.1 聚苯乙烯泡沫 1

1.2.2 聚氨酯泡沫 4

1.2.3 聚氯乙烯泡沫 7

1.2.4 环氧泡沫 9

1.3 发泡剂的分类 11

1.3.1 物理发泡剂 12

1.3.2 化学发泡剂 12

1.4 低密度化方法 14

1.4.1 发泡法 14

1.4.2 轻质填料法 15

1.4.3 后发泡工艺 16

第二章 实验部分 18

2.1 引言 18

2.2 实验原料及配方 19

2.2.1 实验原料 19

2.2.2 实验配方 19

2.3 实验仪器 20

2.4 实验原理 20

2.5 实验方法 21

2.5.1 ABVN分解动力学研究 21

2.5.2复合发泡剂的用量、配制以及成型温度的选择 22

2.6 测试分析方法 22

2.6.1 表观密度的测定 22

2.6.2 压缩强度的测定 23

第三章 实验结果与讨论 25

3.1 AIBN/ ABVN分解动力学特性 25

3.2 单一发泡剂制备LDUPR 27

3.3 AIBN/ABVN 复合发泡剂制备LDUPR 28

第四章 结论与展望 33

4.1 结论 33

4.2 展望 33

参考文献 34

致 谢 37

AIBN/ABVN复合发泡法制备低密度不饱和树脂材料

摘 要

低密度化是不饱和聚酯树脂(UPR)材料的发展趋势之一,在UPR基体中引入气体制成气-固两相复合材料是制备低密度不饱和聚酯树脂(LDUPR)的重要途径。在常用的化学发泡法中,单一发泡剂往往具有难以适应树脂凝胶固化的缺陷[。偶氮二异丁腈(AIBN)和偶氮二异庚腈(ABVN)是两种常用的、应用于自由基聚合反应的偶氮类引发剂,它们受热分解时能同时产生氮气和初级自由基,这是树脂的发泡和固化同时进行的有利条件。AIBN和ABVN的活性不同,两者制备出的LDUPR在性能上会存在差异,以其中一种为主发泡剂并复合另一种发泡剂,达到协同发泡的最佳效应。

本工作在研究AIBN与ABVN的分解动力学基础上,分别以单一AIBN发泡剂、单一ABVN发泡剂、不同比例AIBN与ABVN复合发泡剂用于LDUPR的制备;比较所制得样品表观密度和压缩强度的变化,确定适用于LDUPR的最佳发泡剂配方和成型工艺;微观形貌和示差扫描量热分析表明,复合发泡剂双引发、双重发泡的作用机制是区别于单一发泡剂的关键因素。

依据偶氮二异丁腈(AIBN)和偶氮二异庚腈(ABVN)分解动力学实验,确定两者复合用于制备低密度不饱和聚酯树脂(LDUPR)的最佳半衰期t1/2=1h,最佳质量配比为AIBN:ABVN=7:3,成型温度为78.7℃。当复合发泡剂的用量为树脂质量的2.0%时,LDUPR的表观密度为0.365 g·cm-3、压缩强度(10%)为12.99 MPa,比压缩强度达到最大35.58 MPa/(g·cm-3),高于硬质聚氨酯泡沫(28~35 MPa/(g·cm-3))和聚苯乙烯泡沫(20~27 MPa/(g·cm-3))的比压缩强度。提出复合发泡剂双引发、双重发泡机制,复合发泡剂双重的放热性质,造成树脂胶液适当的延缓凝胶,促使第一阶段产生的细小泡核在延缓凝胶的胶液中成长,同时进行第二阶段的补充发泡,使UPR胶液固化前达到最佳的含泡状态。

关键词:不饱和聚酯树脂 偶氮二异丁腈/偶氮二异庚腈 发泡剂 泡沫

AIBN / ABVN Preparation of low-density composite foam unsaturated resin material

Abstract

LDL is one of the unsaturated polyester resin (UPR) material trends , the introduction of gas into the air in the UPR matrix - solid two- phase composite material is an important way to low-density unsaturated polyester resin (LDUPR) prepared . In the conventional chemical foaming method , a foaming agent tends to be difficult to adapt to a single resin gels curing defects. Azobisisobutyronitrile (AIBN) and azobis- heptanenitrile (ABVN) are two commonly applied azo radical polymerization initiators which decompose upon heating to produce nitrogen gas and simultaneously primary radicals this is advantageous conditions for foaming and curing the resin simultaneously. AIBN and ABVN activity different , LDUPR both prepared for there to be differences in performance to one another based foaming agent and foaming agent compound to achieve the best synergistic effect foaming .

The research work on the basis of the decomposition kinetics of AIBN and ABVN respectively on the single blowing agent AIBN single ABVN blowing , the ratio of AIBN with different blowing agents LDUPR ABVN for composite ; apparent comparison sample was prepared changes in the density and compressive strength , determine the best formulation LDUPR blowing and molding process ; microstructure and differential scanning calorimetry analysis showed that the composite double- foaming trigger mechanism of action is different from the single double -foamed the key factor in the blowing agent.

According to azobisisobutyronitrile (AIBN) and azobis- heptanenitrile (ABVN) decomposition kinetics experiment, the compound used in the preparation of both the unsaturated polyester resin of low density (LDUPR) the best half-life t1/2 = 1h, best quality ratio of AIBN: ABVN = 7:3, molding temperature of 78.7 ℃. When the amount of the blowing agent is a resin composite mass 2.0%, LDUPR apparent density of 0.365 g·cm-3, the compression strength ( 10% ) of 12.99 MPa, than the maximum compressive strength of 35.58 MPa / (g·cm-3), higher than the rigid polyurethane foam (28 ~ 35 MPa / (g·cm-3)) and polystyrene foam (20 ~ 27 MPa / (g ·cm-3)) than the compressive strength. Foaming agent made ​​of composite double trigger , the exothermic nature of the double- foam system , dual composite foaming agent , resulting resin glue appropriate delay gel , prompting the first stage of tiny bubbles produced in delaying the nuclear glue in gel growth , while the second phase of the foam to supplement , so that optimum curing glue UPR bubble containing state before .

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