A series of modified poly(vinyl chloride) (PVC) with n-octadecanethiol

denoted as PVCS18

have been prepared through a nucleophilic substitution reaction

where the different substitution degrees (DS) are realized.The structure

phase change properties and thermal stability of PVCS18 comb-like polymers are systematically characterized by Fourier transform infrared spectroscopy (FTIR)

hydrogen nuclear magnetic resonance spectroscopy (1H-NMR)

differential scanning calorimertry (DSC)

thermogravimetric analysis (TG) and wide-angle X-ray diffraction (WAXD).The results demonstrate that the DS has a big influence on the structure and properties of PVCS18 comb-like polymers.With increasing the DS of C18 alkyl side chains

PVCS18 exhibits an interesting variation for phase transition and thermal performance

contributed from the grafted C18 side chains along PVC backbones.With DS increasing from 8.5% to 50.2%

the phase transition temperature changed from 61.7℃ to 66.3℃

the melting enthalpy increased from 5.3 kJ/mol to 50.9 kJ/mol

and the crystallizable number of carbon atoms also increased from 1.4 to 13.8

accompanied with the enhanced crystallinity of C18 alkyl side chains.The chemical junction between the main-chain and side-chains has an important effect on the crystallizable number of carbon atom per side chain

and the smaller the polarity and size of chemical junction

the higher the crystallization ability of side alkyl group is.In addition

PVCS18 comb-like polymer shows a similar thermals stability with that of pristine PVC

demonstrating that the incorporated alkyl side chains do not alter the thermal stability of PVC

showing a promising application perspective.