作　　者： ; ; (李兵）; (曾昆）; (徐斌）; (罗烽）;

机构地区： 哈尔滨工业大学

出　　处： 《高分子材料科学与工程》 2014年第12期103-107,112,共6页

摘　　要： 应用了一种新颖的微型超声粉末模压成型方法(micro-UPM)成型超高分子量聚乙烯(UHMWPE)微塑件。先利用超声振动使UHMWPE粉末自身快速加热并塑化,之后在合模压力下快速充填微型腔,成功制备了多种规格的微塑件。差示扫描量热实验结果表明,micro-UPM UHMWPE微塑件为两相状态,由初生态和熔化-再结晶态两相组成。在超声塑化时间为0.5~1.5 s的范围内,熔化-再结晶相熔融峰面积逐渐增大,而初生态相熔融峰面积逐渐缩小,结晶度逐渐减小。当超声塑化时间为1.5 s时,微塑件结晶度达到最小值54.3%,而熔化-再结晶相分数达最大值98.3%,micro-UPM UHMWPE微塑件塑化质量最佳。单晶X射线衍射实验表明,微塑件中间区的结晶度数值比表层大,与普通注塑成型的微塑件相比,micro-UPM微塑件的结晶取向性不明显。 Through micro ultrasonic powder molding( micro-UPM),micro semi-crystalline polymer parts were formed. By the proposed method,semi-crystalline polymer powder was rapidly heated and plasticized by ultrasonic vibration,after which the microcavity was filled with the melt under sonotrode pressure( pu) to form a variety of micro polymer parts. Differential scanning calorimetry,scanning electron microscopy,and nanoindentation tests demonstrate that micro-UPM ultra-high molecular weight polyethylene( UHMWPE) parts consist of nascent and melt-recrystallized phases. Different tu( 0. 5 ~ 1. 5 s) values are utilized to form UHMWPE parts at puof 16 MPa and the holding time of 5. 0 s.As tuincreases,a rise in the melting peak of the melt-recrystallized phase and a drop in the melting peak of the nascent phrase as well as crystallinity are further observed. When tuis only 1. 5 s,the crystallinity of the micro plastic part reaches the minimum value of 54. 3% and the melt-recrystallized phase fraction fRreaches the maximum value of 98. 3%.Powder particle interfaces almost disappear in this case,and optimum quality of the micro UPM UHMWPE part is achieved. Single-crystal XRD tests demonstrate that the crystallinity in the core region of the micro polymer part is higher than that in the skin region. Compared with conventional microinjection plastic parts,the crystal orientation of microUPM polymer parts is less obvious.

关 键 词： 微塑件 模压成型 超声振动 超高分子量聚乙烯

领　　域： [化学工程]