Microstructure and Mechanical Properties of Poly （Vinyl Chloride） Modified by Silica Fume /Acrylic Core-Shell Impact Modifier Blends
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2012年第5期
论文作者：黄健 马保国
文章页码：886 - 891
摘 要：This research explored replacing acrylic core-shell impact modifier （AIM） by silica fume to toughen PVC. 100%, 75%, 50% and 25% of AIM （8 phr） were substituted by silica fume in PVC respectively, and then processed by dry blending and twin-screw extrusion. Severe silica fume agglomeration was observed by scanning electron microscope （SEM） in the PVC matrix when 8 phr pure silica fume was used and processed by screw speed of 20 rpm. Its tensile strength was thereby reduced by 38% comparing to unmodified PVC. The silica fume was successfully dispersed while the screw speed was slowed down to 10 rpm to give a stronger screw torque and a longer melt residential time in the extruder. The tensile strength was ’recovered’ to a level comparable to unmodified PVC. Impact test were performed on all formulations extruded at 10 rpm screw speed and synergetic toughening effect was found with 50% substitution and it had the impact strength that was comparable to 8 phr pure AIM toughened PVC.
黄健1，马保国2
1. The Green Building Materials and Manufacturing Engineering Research Center of Ministry of Education,Wuhan University of Technology2. State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology
摘 要：This research explored replacing acrylic core-shell impact modifier （AIM） by silica fume to toughen PVC. 100%, 75%, 50% and 25% of AIM （8 phr） were substituted by silica fume in PVC respectively, and then processed by dry blending and twin-screw extrusion. Severe silica fume agglomeration was observed by scanning electron microscope （SEM） in the PVC matrix when 8 phr pure silica fume was used and processed by screw speed of 20 rpm. Its tensile strength was thereby reduced by 38% comparing to unmodified PVC. The silica fume was successfully dispersed while the screw speed was slowed down to 10 rpm to give a stronger screw torque and a longer melt residential time in the extruder. The tensile strength was ’recovered’ to a level comparable to unmodified PVC. Impact test were performed on all formulations extruded at 10 rpm screw speed and synergetic toughening effect was found with 50% substitution and it had the impact strength that was comparable to 8 phr pure AIM toughened PVC.
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