双元改性剂协同调控聚乳酸结晶及性能研究

发布时间：2018-04-19 14:29

本文选题：聚乳酸 + 双元改性剂　；参考：《宁夏大学》2017年硕士论文

【摘要】：针对聚乳酸(PLLA)结晶速率慢、韧性差的不足,本文通过添加双元改性剂(TMC-210/Talc、TMB-5/PEG、TMC-328/TMP-6)来实现PLLA结晶与性能的调控。利用差示扫描量热仪(DSC)、X射线粉末衍射仪(WAXD)、小角X射线散射仪(SAXS)、扫描电子显微镜(SEM)、偏光显微镜(POM)和力学性能测试考察了双元改性剂对PLLA的结晶行为与韧性的影响。首先,将不同比例的改性剂TMC-210/Talc与PLLA进行熔融共混,并考察二者对PLLA结晶能力和力学性能的影响。研究发现,TMC-210/Talc协同改善了 PLLA的结晶能力,使结晶速率加快、成核密度增加,晶体尺寸和长周期均减小,但对PLLA的结构和晶型没有影响。力学测试表明,添加4%的Talc,使PLLA/TMC-210/Talc共混材料的断裂伸长率达到23.6%,比PLLA/TMC-210共混物提高了 262%。当添加含量为1%的Talc时,PLLA/TMC-210/Talc共混材料的韧性达到最高为5.65 KJ/m2,比PLLA/TMC-210共混物和纯PLLA分别提高了 29.3%和2.1倍。其次,利用增塑剂PEG对PLLA/TMB-5共混材料进行改性。研究结果表明,在PLLA中添加TMB-5与PEG后,PLLA的玻璃化转变温度下降,结晶峰温度向高温方向移动,结晶速率和成核速率均加快,球晶尺寸变大,同时伴随有环带球晶的出现,但对PLLA的结构和晶型没有影响。力学测试表明TMB-5/PEG协同改善了 PLLA的韧性,在TMB-5的含量为0.5%、PEG的含量为3%时,PLLA/TMB-5/PEG共混材料的韧性达到最高为5.05KJ/m2,较PLLA/TMB-5混合物及纯PLLA分别提高了 22.9%和1.5倍。最后,采用熔融共混的方法制备了 PLLA/TMC-328/TMP-6共混材料,系统研究了双元改性剂对PLLA结晶行为、晶体形态和力学性能方面的影响。结果表明,双元改性剂TMC-328/TMP-6显著提高了聚乳酸的结晶峰温度和结晶速率,成核效果优于传统的单一 TMC-328改性剂,且不影响PLLA的结构和晶型。另外,适量的双元改性剂可以提高PLLA的韧性,在TMC-328含量为0.6%,TMP-6的含量为0.4%时,PLLA/TMC-328/TMP-6共混材料的韧性达到了最大值4.33 KJ/m2,较PLLA/TMC-328共混物和纯PLLA分别约提高了 10.9%和1.3倍。
[Abstract]:In view of the low crystallization rate and poor toughness of polylactic acid (PLLA), the crystallization and properties of PLLA are regulated by adding TMC-210 / Talc / TMB-5 / PEGN TMC-328 / TMP-6.The effects of binary modifiers on the crystallization behavior and toughness of PLLA were investigated by means of differential scanning calorimeter (DSC), small angle X-ray diffractometer (SAXS), scanning electron microscope (SEM) and polarizing microscope (Poms).Firstly, different ratio of modifier TMC-210/Talc and PLLA were melt blended and their effects on crystallization ability and mechanical properties of PLLA were investigated.It is found that TMC-210 / Talc synergistically improves the crystallization ability of PLLA, accelerates the crystallization rate, increases the nucleation density, decreases the crystal size and long period, but has no effect on the structure and crystal form of PLLA.The mechanical tests show that the elongation at break of PLLA/TMC-210/Talc blends can reach 23.6 by adding 4% Talc, which is 2622% higher than that of PLLA/TMC-210 blends.When 1% Talc was added, the toughness of PLLA / TMC-210 / Talc blends reached a maximum of 5.65 KJ / m ~ 2, which was 29.3% and 2.1 times higher than that of PLLA/TMC-210 blends and pure PLLA, respectively.Secondly, PLLA/TMB-5 blends were modified by plasticizer PEG.The results show that the glass transition temperature of PLLA decreases with the addition of TMB-5 and PEG, the crystallization peak temperature shifts to high temperature, the crystallization rate and nucleation rate are accelerated, and the spherulite size becomes larger, accompanied by the appearance of ring spherulites.However, there is no effect on the structure and crystal form of PLLA.The mechanical tests show that TMB-5/PEG synergistically improves the toughness of PLLA. When the content of TMB-5 is 0.5%, the toughness of PLLA / TMB-5 / PEG blend is 5.05 KJ / m2, which is 22. 9% and 1. 5 times higher than that of PLLA/TMB-5 mixture and pure PLLA, respectively.Finally, PLLA/TMC-328/TMP-6 blends were prepared by melt blending. The effects of binary modifiers on the crystallization behavior, crystal morphology and mechanical properties of PLLA were systematically studied.The results showed that the crystallization peak temperature and crystallization rate of polylactic acid were significantly increased by TMC-328/TMP-6, and the nucleation effect was better than that of single TMC-328 modifier, and the structure and crystal form of PLLA were not affected.In addition, the toughness of PLLA can be improved by a proper amount of binary modifier. When the content of TMC-328 is 0.6 and TMP-6 is 0.4, the toughness of PLLA-TMC-328 / TMP-6 blends reaches a maximum value of 4.33KJ / m2, which is about 10.9% and 1.3 times higher than that of PLLA/TMC-328 blends and pure PLLA blends, respectively.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O633.14

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