Efficient internal plasticization of poly(vinyl chloride) via free radical copolymerization of vinyl chloride with an acrylate bearing a triazole phthalate mimic

Abstract

Nonmigratory internal plasticization of poly(vinyl chloride) (PVC) is achieved by synthesis of poly(vinyl chloride)-co-poly(4,5-bis(2-ethylhexyl)-1-[6-prop-2enoyloxy)hexyl]-1H-1,2,3-triazole-4,5-dicarboxylate) [PVC-co-P(DEHT-HA)] copolymers via free radical polymerization (FRP). Optimization of the polymerization temperature, solvent, initiator, and vinyl chloride / acrylate (VC/DEHT-HA) monomer ratio were systematically investigated, and the corresponding glass transition temperatures (Tg) of the resultant copolymers determined. These internally plasticized copolymers were characterized by 1 H NMR, FTIR, SEC and DMTA. The Tg values of the PVC-co-P(DEHT-HA) copolymers range from -27 to 78 ºC, and the physical properties suggest that the P(DEHT-HA) and PVC segments are miscible.Thermogravimetric analysis shows that increasing the ratio of the monomer DEHT-HA to vinyl chloride increases the thermal stability. By varying the initial VC/DEHT-HA monomer ratio, one can tune the Tg of the resulting copolymer, making both the strategy and the polymer flexible.

“All-PVC” Flexible Poly(vinyl Chloride): Nonmigratory Star-Poly(vinyl Chloride) as Plasticizers for PVC by RAFT Polymerization

“…The star-PVC plasticizers behave like other internal plasticizers for PVC and increase the distance between PVC chains. 13,25,78 The star-PVC plasticizers can orientate, and the arms align with PVC chains under stress. The end result is that toughness of plasticized PVC is enhanced and cold drawing is observed, as shown in Figure 5.…”

“…Another strategy, called internal plasticization or self-plasticization, involves the usage of an additive formed by modification of PVC or a related polymer through covalent grafting of functionality [e.g., a phthalate or a low T g polymer such as poly­(butyl acrylate) (PBA)] to the PVC backbone . Grafting has been achieved by many methods including azide–alkyne cycloaddition (sometimes called “click” chemistry) − and various approaches based on atom transfer radical polymerization (ATRP) (see also below). ,− Yuan and Cheng attached DOP to a chlorinated paraffin to provide a nonmigrating plasticizer . These internal plasticizers show markedly better migration resistance than low molar mass plasticizers.…”

Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

“…The copolymerization approach to the nonmigratory internal plasticization was further developed in a recent research study of this group, where the PVC plasticization was achieved through the free radical copolymerization of vinyl chloride with 4,5-bis(2-ethylhexyl)-1-[6-prop-2-enoyloxy)hexyl]-1H-1,2,3-triazole-4,5-dicarboxylate (DEHT-HA) [ 108 ]. The DMA analysis of a PVC-co-P(DEHT-HA) copolymer with 75% content of vinyl chloride showed a single T g (46.8 °C) that was lower than expected from the study of pure components.…”

“…The acquired results implied that both segments were well miscible, and some synergistic effect was achieved. Varying the monomer ratio allowed us to tune the T g of the resulting copolymer in a range between −27 and 78 °C [ 108 ].…”

Tetrabutylammonium tetrafluoroborate electrolyte as poly(vinyl chloride-co-vinyl acetate-co-2-hydroxypropyl acrylate) plasticizer: Thermal degradation and optical characteristics

“…Heating the polymer above Tg creates more free volume which is occupied by plasticizer resulting in lowering Tg by separating PVVH chains [41]. The spectacular reduction in Tg of PVC due to external and internal plasticizers have been report by many researchers [42][43][44][45][46]. For example, Li et al [44] have incorporated four plasticizers to PVC chain via glutamic acid linker and found strong depression of Tg for PVC-triethylene glycol esters compared to PVC-alkyl esters.…”