Longjun Li, Guochen Wang, Like Sun, Changtong Song, Dong Chen, Yuhong Ma, Wantai Yang
ABSTRACT Small molecular plasticizers, widely used in flexible poly(vinyl chloride) (PVC), suffer from drawbacks including high migration rate and safety concerns. Low molecular weight polyesters are developed to address the challenges. In this contribution, adipic acid and 2‐methyl‐1,3‐propanediol are used as monomers, and different monohydric alcohols are applied as capping agents to prepare symmetrically capped poly(2‐methyl‐1,3‐propanediyl adipate) (PMPA) and asymmetrically capped poly(2‐methyl‐1,3‐propanediyl adipate) (APMPA). The prepared PMPA and APMPA with different molecular weights are evaluated as PVC plasticizers. The results demonstrate that both PMPA and APMPA exhibit better plasticizing efficiency than that of common dioctyl phthalate (DOP). For instance, with 70 phr APMPA, PVC‐APMPA3 (Using MPEG 600 g/mol as a capping agent) shows an elongation at break of 460% and a glass transition temperature ( T g ) of −19.1°C, along with significantly reduced migration loss (mass loss < 2% after 7‐day immersed in petroleum ether). Furthermore, it presents an excellent hydrophilic durability, from about 24° decreases to 22° after immersed in water for 28 days. Notably, APMPA3, featuring asymmetrical α‐ and ω‐end groups, not only demonstrates better plasticizing performance and low migration than that of DOP, but also offers the plasticized PVC an excellent and long‐term hydrophilicity.