摘要
Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- propyl-heptaisobutyl POSS with DMDBS（POSS-DMDBS）, and physical mixing of DMDBS with octaisobutyl POSS （iso-POSS/DMDBS） or trisilanolisobutyl POSS（tri-POSS/DMDBS） were applied respectively to modifying iPP, and the effects of POSS and DMDBS on crystallization, rheological and mechanical properties of iPP were systematically investigated. The results indicate that iso-POSS/DMDBS and tri-POSS/DMDBS were more effective than POSS-DMDBS on the improvement of the crystallization behavior of iPP due to the higher crystallization temperature, while the crystal!inity of iPP containing POSS-DMDBS was enhanced, approximately approached to that of iPP containing tri-POSS/DMDBS. The tensile strength of iPP with POSS-DMDBS was significantly increased from 34 MPa to 40 MPa, as high as that of iPP with iso-POSS/DMDBS. The different effects caused by the specific interaction between POSS and DMDBS could possibly be applied in the modification of iPP.
Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- propyl-heptaisobutyl POSS with DMDBS（POSS-DMDBS）, and physical mixing of DMDBS with octaisobutyl POSS （iso-POSS/DMDBS） or trisilanolisobutyl POSS（tri-POSS/DMDBS） were applied respectively to modifying iPP, and the effects of POSS and DMDBS on crystallization, rheological and mechanical properties of iPP were systematically investigated. The results indicate that iso-POSS/DMDBS and tri-POSS/DMDBS were more effective than POSS-DMDBS on the improvement of the crystallization behavior of iPP due to the higher crystallization temperature, while the crystal!inity of iPP containing POSS-DMDBS was enhanced, approximately approached to that of iPP containing tri-POSS/DMDBS. The tensile strength of iPP with POSS-DMDBS was significantly increased from 34 MPa to 40 MPa, as high as that of iPP with iso-POSS/DMDBS. The different effects caused by the specific interaction between POSS and DMDBS could possibly be applied in the modification of iPP.
