聚丙烯物理法微孔发泡操作条件与泡孔形态的关系研究_汪菊英

聚丙烯物理法微孔发泡操作条件与泡孔形态

的关系研究

汪菊英1,张兴华2

(11广东白云学院机电工程系,广东广州510450;21广东工业大学材料与能源学院,广东广州510006) 摘要:以超临界CO 2流体和丁烷为发泡剂,用快速释压的方法,对PP 的微孔发泡进行了研究,得到了泡孔密度达109泡孔/cm 3,泡孔直径为20~50L m 的微孔泡沫塑料颗粒。研究表明,改变饱和压力和温度可以控制发泡的泡孔结构和密度。使用CO 2为发泡剂,当温度低于90e 或压力低于610MPa 时,PP 很难出现发泡。提高温度使泡孔出现五边形的结构但泡孔尺寸增大;增加饱和压力,泡孔密度增加,泡孔直径减小。用超临界CO 2流体和丁烷作发泡剂时所得到的泡孔密度分别为210@108~109和210@105~107泡孔/cm 3,泡孔平均尺寸分别为20~50L m 和100~500L m 。用超临界C O 2流体和丁烷混合气体作为发泡剂时泡孔直径则出现了双峰分布的结构;加入成核剂炭黑后所得到的泡孔尺寸大于未加成核剂的情况,其泡孔密度和泡孔直径分别为710@106~116@109泡孔/cm 3和55~300L m 。

关键词:超临界CO 2;微孔发泡;快速释压;PP 微孔发泡

中图分类号:TQ32511+4 文献标识码:A 文章编号:1005-5770(2007)05-0058-04

Study on Relationship between Cellular Morphology of PP and Foaming C ondition by

Physical Blowing Agents

W ANG Ju -ying 1,Z HANG Xing -hua 2

(1.Dep t 1of Electromechanical Eng 1,Guangdong Baiyun Institute,Guangzhou 510450,China;2.Faculty of Material and Energy,Guangdong University of Technology,Guangzhou 510006,China)

Abstract:With supercritical CO 2or/and butane as blo wing agent,the microcellular foa m of PP blown by means of quick depressurization was studied,and microcellular PP,with cell density of about 109cells/cm 3and cell diameter of 20~50L m,was prepared 1The results sho wed the cell density and size c ould be controlled by changing the foaming te mperature and saturated pressure 1When CO 2was used as blowing a gent,it was difficult to make PP

foa med while the te mperature was lower than 90e or the saturated pressure was lower than 610MPa 1With the foa ming temperature rose to 108e ,the cell structure beca me pentagon and the cell size increased 1With the higher foa ming pressure,the cell density increased and cell size decreased 1The cell density was 210@108

~109

and 210@105~107cells/cm 3,and the cell diameter was 20~50L m and 100~500L m for the samples respectively blown by supercritical CO 2and butane 1The cell size distribution appeared double peaks while using the mixture gas of CO 2with butane 1The cell density and diameter was 710@106~116@109cells/cm 3and 55~300L m respectively while adding carbon black as nucleating a gent,the cell size was bigger and the cell density was lo wer than that without carbon black,which was due to the different nucleation mechanics 1

Keywords:Supercritical C O 2;Microcellular Foaming;Quick Depressurization;PP Microcellular Foaming

微孔聚合物具有韧性高、比强度高、疲劳寿命长、热稳定性高、介电常数低和导热系数低等优异的综合性能

[1]

。在微孔聚合物发泡时使用超临界流体是

20世纪90年代初提出的新方法[2,3]

。本文着重研究

了快速释压法发泡PP 时发泡压力、发泡温度等因素

对泡孔密度和泡孔大小的影响,同时还比较了用超临界CO 2流体和丁烷作发泡剂时泡孔直径和泡孔密度的变化。

1 实验部分

111 实验原料

#

58#塑料工业

CHINA PLASTICS INDUSTRY 第35卷第5期2007年5月

X 作者简介:汪菊英,女,1971年生,硕士生,工程师,主要从事高分子材料成型及设备方面的研究。wangjy714@1631com