| Abstract: | The improvement of the impact strength of the telecommunication equipment using injection moldable PVC/MBS and other modifiers were studied. The addition of MBS to the PVC was found with rapid increases in the impact stregths in Kg-cm/cm: 5.5 of pure PVC; 80 of 12 phr and the maximum of 131 of 20 phr of MBS. This increasing impact strength phenomena were subjected to close examinations of SEM, DMTA, and strain-stress diagrams. The DMTA analysis of the retaining of the individual Tg's of MBS and PVC in the MBS/PVC blends, indicates that no miscibility of MBS and PVC has occurred. The DMTA diagrams of 5, 12, 20, and 30 phrs of MBS in PVC were analyzed and the same samples were also subjected to the impact strength measurements and the SEM examinations. SEM photos showed a gradual transition of the linear to the three-dimensional arrangements had occurred in the PVC/MBS blends. The formation of three-dimensional arrangement occurred between 10–20 phr of added MBS. The spacial change from linear to the three-dimensional arrangements observed in SEM photos correlates the rapid increases of the impact strengths of the specimens tested. Injection specimens of the telephone sets made of PVC/MBS blends with 20 phr of MBS in PVC indicate that the impact strength is averaged at 115 Kg-cm/cm with tensile strength of 330 Kg/sq cm and elongation of 150%. The similar change of the spacial arrangement is also observed in their SEM photos. |
