Structure And Properties Of Long Chain Thiolated PVC Comb Polymer

Polyvinyl chloride (abbreviation for PVC) with great prospects and market competitiveness, is the second general plastic in the world, but its application has been restricted because of its poor thermal stability and impact resistance. In this paper, a series of branched PVC derived comb-like polymers with different lengths of n-alkanethiol side-chains, denoted as PVCS(n)s (n=12,14,16,18, number of carbon atoms in n-alkanethiol side group), have been prepared by a nucleophilic substitution reaction. And the polysulfone comb-like polymers, denoted as PVCSO2(n)s, have been prepared by a oxidation reaction of PVCS(n)s. The PVCS(n)s and PVCSO2(n)s comb-like polymers are systematically characterized by Fourier transform infrared spectroscopy (FTIR). nuclear magnetic resonance spectroscopy (’H NMR). differential scanning calorimertry (DSC)、thermal gravimetric analysis (TG) and wide-angle X-ray diffraction (WAXD) etc to study the thermal stability and crystallization behaviors. Studies show that, PVCS(n)s and PVCSO2(n)s don’t undermine the thermal stability of PVC. The melting enthalpies of the comb-like polymers both increase with the number of carbon atoms in side group improving, for PVCS(n)s the melting enthalpy increase from 14.6 kJ/mol (C12) to 50.9 kJ/mol (C18), and for PVCSO2(n)s the melting enthalpy increase from 1.3 kJ/mol (C16) to 22.3 kJ/mol(C18).The density of alkyl side chain grafting onto main chain will influences the structure of the polymer crystals. In this paper, a series of PVCS(18)s comb-like polymers with different degree of substitution (DS) have been prepared. We systematically study the density of alkyl side chains how to influence the thermal stability、thermal properties and contact angle of comb-like polymers. It shows that, The thermal stability of comb-like polymers increases with the increasing DS. For PVCS(18)s, the melting enthalpy increases from 5.3 kJ/mol (DS=8.5%) to 50.9 kJ/mol (DS=50.2%); contact angle increases from 88.6° (DS=8.5%) to 151.3 ° (DS = 50.2%).In this paper, we also explores the electrospinning conditions for PVCS(18)s comb-like polymer with different DS, and the morphology、thermal stability and thermal properties of nanofibers were also studied. The results show that, PVCS(18)s comb-like polymers with DS≤14.3% can be electrospinned, and the enthalpy reaches 18.0 kJ/mol. And nanofibers don’t destroy the thermal stability of the PVCS(18)s comb-like polymers.