节点文献
具有优良刚性的增韧高密度聚乙烯工程塑料的研究
The Study of the Toughened HDPE Engineering Plastics with Excellent Rigidity
【作者】 樊卫华;
【导师】 王经武;
【作者基本信息】 郑州大学 , 有机化学, 2006, 博士
【摘要】 对高密度聚乙烯(HDPE)进行增韧,使这一大品种通用塑料能够作为工程塑料使用,是国内外研究开发新型工程塑料的一个重要方向。从目前国内外研究开发的情况看,用弹性体增韧的增韧效果最好,但是,一般的弹性体增韧使HDPE韧性大幅度提高的同时,刚性(拉伸屈服应力、弯曲弹性模量)却显著降低了;用刚性粒子(有机粒子、无机粒子)增韧,具有优良的刚性,但是,韧性提高的幅度小,而且主要适用于韧性已比较好的HDPE。因此,如何使弹性体增韧HDPE韧性大幅度提高的同时又能较高的保持优良的刚性,是亟待解决的具有重要科学技术意义和应用价值的课题。 本工作在分析出一般的弹性体增韧HDPE韧性大幅度提高的同时刚性显著降低在结构方面三个原因的基础上,设计出了能呈现优良刚性的弹性体增韧HDPE必须具有的结构特征;为了获得好的技术/经济比,设计采用增韧母料(TMB)工艺,即首先制备出具有所设计结构特征的TMB,用TMB与HDPE热机械共混制备增韧HDPE的过程中,将TMB的结构特征“移植”到增韧HDPE中。 基于此,运用本工作研究出的“聚合桥连接、动态硫化、微相分离”制备TMB的原理和技术,以2200JHDPE(记为E1)或5000SHDPE(记为E2)为基体树脂,乙丙弹性体和/或丁苯弹性体为增韧剂,加入架桥剂等,研制出了不同配方的称为E型的增韧母料(E-TMB,分为E1-TMB和E2-TMB),将E-TMB与HDPE热机械共混,制备出了多种类型的增韧HDPE(HDPE/E-TMB)。采用分级提取、IR、TEM、PLM、DSC、DTA、SEM、电子万能试验机、毛细管流变仪等研究了E-TMB的化学与形态结构、熔体流动性,HDPE/E-TMB的形态结构、力学性能、脆韧转变机理,热性能、熔体流变行为、非等温结晶行为等,并提出和验证了表征聚合物、聚合物共混物熔体表观粘度(η_a)与温度(T)及剪切速率((?))关系的线性方程。得到了如下主要结果和结论: 1.在所研究的配方范围内,E1-TMB和E2-TMB中以接枝共聚物、交联聚合物形式存在的弹性体的含量分别为15.31%~25.56%(占弹性体总量的51.39%~76.03%)和9.99%~12.85%(占弹性体总量的29.60%~36.83%),以接枝共聚物、交联聚合物形式存在的HDPE的含量分别为2.41%~11.51%(占HDPE总量的5.27%~19.10%)和4.09%~11.36%(占HDPE总量的7.98%~19.17%),由于接枝共聚物的含量分别只有0.51%~4.49%和1.74%~2.34%,所以,这两类E-TMB中以接枝共聚物、交联聚合物形式存在的弹性体及HDPE的绝大多数,主要是以通过聚合桥链连接的
【Abstract】 It is an important orientation to toughen HDPE so that this kind of common plastic can be used as engineering plastic. At present, the best way is elastomer toughening, but it is at the cost of lossing rigidity(etc. TYS, FM). Good rigidity can be achieved by using rigidity particles (organic, inorganic), but the improvement of toughness is limited and this method is mainly suitable for HDPE with good toughness. So it has become an urgent problem to improve the toughness of elastomer toughening HDPE and keep its rigidity at the same time, which is important to the science and application.At first, the relationship between the toughness and the rigidity was analysed, and then we designed the special structure elastomer toughening HDPE, which showed excellent rigidity. In order to obtain satisfied ratio of technique to economy, the designation adopted TMB process, that is, preparing TMB with the designed structure character first, and then transplanting this structure character of TMB into HDPE through thermal mechanical blending of TMB and HDPE.Based on our design, E-type toughening master batch (E-TMB, including E1-TMB and E2-TMB) in different batch formula was developed by using the mechanism and technique of "polymer-bridge conjunction, dynamic vulcanization and microphase separation" which had been used to prepare TMB during former work, with 2200JHDPE(E1) or 5000SHDPE (E2) as matrix resin, EPR or SBR as toughening agent and the addition of bridge agent. Several types of toughened HDPE (HDPE/E-TMB)were prepared by thermal mechanical blending of E-TMB and HDPE. The chemical and morphological structure and MFR of E-TMBs, the morphology, mechanical properties, brittle-ductile transition mechanism, thermal properties, rheological properties, non-isotheremal crystalline behavior of HDPE/ETMBs were characterized by using fraction extraction, TEM, PLM, DSC, TG, DTA , SEM techniques as well as electronic universal testing machine and capillary rheometer etc, and the linear equation was put forward and validated to characterize the relation between apparent viscosity (η_a) of polymer melting or polymer blends melting and
【Key words】 High Density Polyethylene; Toughening Master Batch; Toughening; Structure; Properties;