PVC的微发泡处理及PVC/CaCO3的原位复合

研究了用原位生成法制备PVC/纳米CaCO3复合母粒的过程. 首先利用混合溶剂将PVC粉料溶胀，同时带入发泡剂偶氮二异丁腈，在112oC下进行固相微发泡. 利用已发泡的PVC，采用原位生成法制备了纳米CaCO3/PVC复合母粒. 通过扫描电镜观察，发现已发泡PVC颗粒表面布满微孔，纳米级CaCO3填充在PVC孔洞里. PVC/纳米CaCO3复合母粒同时起到了增韧增强的作用.

Preparation of Microporous PVC and in Situ Composite Technology of PVC/CaCO3

This article describes the preparation of PVC/nanometer CaCO3 composite particles by an in situ method. Porous polyvinyl chloride (PVC) particles were swelled by compound solvent with foaming agent 2,2-azo- bis-iso-butyronitrile (AIBN). When heated at 112oC, PVC particles were foamed because AIBN decomposed to gas. When the volume percentage of cyclohexanone in compound solvent reaches 11.7%, the porosity of microporous PVC increases to the maximum of 35.9%. Microporous PVC, Ca(OH)2 and some additives were dispersed uniformly in water and then aerated with CO2, thus PVC/nano-CaCO3 composite particles was prepared by this in situ method. Chemical analysis indicated that the maximal content of synthesized CaCO3 reached 20%. SEM micrographs show that microporous PVC particles had many cavities and nanometer CaCO3 were filled in these cavities at the same time. It is inferred that nanometer CaCO3/PVC mixture toughens and reinforces PVC.