单聚合物复合材料模内自增强成型特性的研究

发布时间：2018-01-06 20:39

  本文关键词：单聚合物复合材料模内自增强成型特性的研究　出处：《大连理工大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： SPC 共注塑 物理可视化技术 型腔压力 熔体温度

【摘要】：单聚合物复合材料(Single Polymer Composites,以下简称SPC)是基体和增强相采用同种(族)聚合物的复合材料。SPC具有比强度高,不存在界面异性,易于回收等优点。传统制备SPC的热压工艺,具有成型过程复杂、效率低和材料选择面窄的局限性,这成为了SPC应用的瓶颈。本文提出了模内自增强复合工艺成型SPC的方法,即利用共注塑工艺制备SPC,通过注塑工艺分别完成SPC基体和增强相的制备,这种方法具有工艺简单、成型周期短和材料选择宽泛等优点。增强相、基体和界面都影响SPC材料整体的性能,尤其是增强相和界面性能；根据聚合物材料的性质,不同注塑工艺参数得到的制品性能也不同；本文利用物理可视化和传感器测量等手段,研究了成型工艺参数对SPC增强相制备过程的影响。以PP作为成型材料,改变增强相的成型条件制备对应的SPC力学性能试样,取单次注塑的未增强试样作为对照,测量各组试样的拉伸强度。当塑化温度为230℃,注射速度为6.11cm3/s时,SPC的拉伸强度最大,比对照组高23.79%。利用物理可视化技术获得不同条件下熔体前沿的流动速度曲线；相对于熔体在金属沟槽的填充,SPC基体的存在使得熔体的流动速度更大,共注塑成型工艺更有利于发挥增强相聚合物的自增强特性；不同增强相尺寸的SPC填充结果表明：尺寸2mm,1.5mm和1mm的增强相均能顺利充满型腔,而尺寸0.5mmm的增强相熔体充模时发生短射现象；相同成型条件,小尺寸增强相的前期流动速度更大,而大尺寸增强相熔体中后期流动速度更大。分别在型腔的近浇口,型腔中部和型腔末端三个位置,利用传感器测量尺寸2mm的SPC增强相成型时的型腔压力和熔体温度。熔体实际流动速度是型腔压力的主要影响因素。对某一成型过程,熔体与接触壁面的热传导以及熔体流动过程中的粘性耗散作用是影响熔体温度的主要因素。利用MoldFlow对本文中所有的实验过程进行了模拟,包括不同增强相尺寸SPC的填充过程和PP熔体在金属沟槽中的填充过程,并分别从熔体流动前沿温度和重新熔化区域两个方面进行了对比分析。塑化温度越高,注射速度越大,对应的熔体流动前沿温度越高,基体界面的重新熔融区域越大；对比力学性能试验结果,说明界面强度是除增强相强度之外,影响SPC拉伸强度的又一主要因素；其他模拟分析结果与前期的实验结果一致。
[Abstract]:Single Polymer Composites. SPCs are composites with the same group of polymers used in matrix and reinforced phase. SPCs have the advantages of high specific strength, no interfacial heterogeneity and easy recovery. Because of the limitation of complex molding process, low efficiency and narrow choice of materials, this has become the bottleneck of SPC application. In this paper, a method of forming SPC by in-mold self-reinforcing composite process is proposed. This method has the advantages of simple process, short molding period and wide selection of materials, and can be used to prepare SPC matrix and reinforcement phase respectively by injection molding process, which has the advantages of simple process, short molding period and wide selection of materials, etc. The method has the advantages of simple process, short molding period and wide selection of materials. Both the matrix and the interface affect the overall properties of the SPC material, especially the reinforcing phase and the interfacial properties. According to the properties of polymer materials, the properties of the products obtained by different injection molding parameters are also different. By means of physical visualization and sensor measurement, the influence of molding process parameters on the preparation of SPC reinforced phase was studied. PP was used as the molding material. The mechanical properties of SPC samples were prepared by changing the forming conditions of the reinforcing phase. The tensile strength of each group of specimens was measured when the plasticizing temperature was 230 鈩，

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