Enhancing gelation properties of dioctyl phthalate using urethane and urea‐based gelators to improve mechanical properties of polyvinylchloride

Abstract

This study provides a new approach to promote the mechanical properties of polyvinylchloride/dioctyl phthalate (PVC/DOP) via gelators. It presented the effect of newly synthesized urethane and urea‐based gelators on the plasticizer DOP, and then prepared for PVC. 4,4′‐Diphenylmethane diisocyanate (MDI) was reacted with lauryl alcohol (LA), stearyl alcohol (SA), and octadecylamine (OL) to prepare LML, SMS, and SMO, respectively. These gelators were self‐assembled in the common plasticizer DOP to form gels, and then PVC was blended with these gels. SMO exhibited the lowest critical gelator concentration (CGC) in DOP. FEEM observation of xerogels exhibited micro platelet morphology with various sizes. Rheological evaluation revealed that DOPgel enhanced the gelating ability of PVC. Mechanical measurement showed that gelators improved the tensile properties of PVC in the sequence of LML > SMS > SMO. Tensile modulus and the tensile strength of PVC/DOP increased by 74.6% (from 14.6 to 25.5 MPa) and 19.8% (from 13.1 to 15.7 MPa) only by adding 3% LML. These new urethane and urea‐based gelators improved the mechanical strength of PVC without reducing its toughness.