Structurally Enhanced Self-Plasticization of Poly(vinyl chloride) via Click Grafting of Hyperbranched Polyglycerol

Revisiting poly(vinyl chloride) reactivity in the context of chemical recycling

Poly(vinyl chloride) (PVC) is one of the highest production volume polymers due to its many applications, and it is one of the least recycled due to its chemical structure and frequent formulation with additives. Developing efficient PVC recycling techniques would enable PVC waste to be reused or repurposed in other processes. Within this context, the literature on PVC modification offers considerable insight into versatile reaction pathways, potentially inspiring new approaches for repurposing PVC waste into value-added products. This perspective provides an overview of PVC functionalization through a lens of chemical recycling, discussing various PVC reactivity trends and their applications with a critical assessment and future outlook of their recycling implications.

Methods for determination of plasticizer migration from polyvinyl chloride synthetic materials: a mini review

Plasticizer migration is responsible for premature coating failure in polyvinyl chloride (PVC) synthetic materials that continue to benefit our daily life as a reliable and cost-efficient simulant of genuine leather. In this context, the establishment of standard assays that measure the migration rate of plasticizers under varying scenarios plays a pivotal role in comparing durability of those PVC-derived leather-simulants. In this review, multiple methodologies developed over the last decade for determining plasticizer migration from PVC coating are compiled, with their operational principles, merits, and limitations being taken into consideration along with specific apparatus required for each. A concluding section discusses current challenges in this field, and highlights how nuclear magnetic resonance and computational simulation surpass conventional assays in yielding intercomparable results, and hence screening migration-resistant plasticizers in a labor- and time-saving way. Since migration resistance represents a decisive performance indicator of plasticizers, this systematic review may provide guidance to quite a few practitioners in PVC synthetic material industry, who are now engaged in validating various sustainable alternatives with performance allegedly equal to conventional but toxic di-(2-ethylhexyl) phthalate plasticizer.

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The Hyperbranched Polyester Reinforced Unsaturated Polyester Resin

We report a method of reinforcing and toughening unsaturated polyester resin (UPR) with a kind of hyperbranched polyester (HBP-1). Polyethylene glycol with different molecular weight was used as the core molecule of the preparation reaction, and the reaction product of phthalic anhydride and glycerol was used as the branching unit. The esterification reaction of polycondensation occurred, and then the hydroxyl-terminated hyperbranched polyester was prepared. The reaction product of maleic anhydride and isooctanol was added to the prepared hydroxyl-terminated hyperbranched polyester for esterification reaction. Both ends of the hyperbranched polyester had unsaturated double bond to obtain the hyperbranched polyester (HBP-1). The effects of this treatment on the morphology, mechanical properties and thermal properties of the composites were studied in detail. The HBP-1 was investigated by Fourier Transform Infrared Spectroscopy (FT-IR). The HBP-1/UPR composites were investigated by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), mechanical properties analysis and Scanning Electron Microscope (SEM). The results showed that HBP-1 enhanced the thermostability and mechanical properties of UPR. However, DMA indicated that the addition of HBP-1 cannot effectively improve the thermodynamic properties of UPR due to the flexible chain in HBP-1 structure. The HBP-1 improves tensile strength, bending strength and impact strength compared to neat UPR.

Nitroxide mediated radical polymerization for the preparation of poly(vinyl chloride) grafted poly(acrylate) copolymers

In view to control the thermal properties of PVC without the use of toxic phthalate derivatives, alkoxyamines were grafted onto an azide modified PVC, through copper catalyzed azide-alkyne cycloaddition (CuAAC),...

Advances in Internal Plasticization of PVC: Copper-Mediated Atom-Transfer Radical Polymerization from PVC Defect Sites To Form Acrylate Graft Copolymers

Internally plasticized PVC copolymers were prepared by grafting PVC with butyl acrylate and 2-(2-ethoxyethoxy)ethyl acrylate by atom-transfer radical polymerization, resulting in well-behaved polymers with a wide range of glass transition temperatures (–54 °C to 54 °C). When the grafted side chains made up more than 50% of the polymer by weight, the glass transition temperatures were below 0 °C. The covalent attachment of the plasticizing grafts requires one simple procedure starting from commercial PVC, making this strategy an industrially relevant and environmentally friendly alternative to the use of conventional small-molecule plasticizers.

Construction of enhanced self-plasticized PVC via grafting with a bio-derived Mannich base

Self-plasticized PVC materials (PVC-ML-g) were successfully prepared via grafting with a lauraldehyde-derived Mannich base and presented improved thermal stability and outstanding anti-migration ability.

High ionic conduction, toughness and self-healing poly(ionic liquid)-based electrolytes enabled by synergy between flexible units and counteranions

Polymer electrolytes offer great potential for emerging wearable electronics. However, the development of a polymer electrolyte that has high ionic conductivity, stretchability and security simultaneously is still a considerable challenge. Herein, we reported an effective approach for fabricating high-performance poly(ionic liquids) (PILs) copolymer (denoted as PIL-BA) electrolytes by the interaction between flexible units (butyl acrylate) and counteranions. The introduction of butyl acrylate units and bis(trifluoromethane-sulfonyl)imide (TFSI⁻) counteranions can significantly enhance the mobility of polymer chains, resulting in the effective improvement of ion transport, toughness and self-healability. As a result, the PIL-BA copolymer-based electrolytes containing TFSI⁻ counterions achieved the highest ionic conductivity of 2.71 ± 0.17 mS cm⁻¹, 1129% of that of a PIL homopolymer electrolyte containing Cl⁻ counterions. Moreover, the PIL-BA copolymer-based electrolytes also exhibit ultrahigh tensile strain of 1762% and good self-healable capability. Such multifunctional polymer electrolytes can potentially be applied for safe and stable wearable electronics.

Polymer electrolytes offer great potential for emerging wearable electronics.

Role of the Oxethyl Unit in the Structure of Vegetable Oil-Based Plasticizer for PVC: An Efficient Strategy to Enhance Compatibility and Plasticization

Developing vegetable oil-derived primary plasticizers for poly(vinyl chloride) (PVC) is still a challenge because of their insufficient compatibility. As described in this work, we report the synthesis of plasticizers through the esterification of polyethylene glycol methyl ether and dimer acid, in which dimer acid is renewable material prepared via a two-step reaction (1) the hydrolysis of fatty acids from soybean oil at 70 °C and (2) subsequent Diels-Alder reaction at 250 °C. The resulting plasticizers, dimer acid-derived polyethylene glycol methyl ether esters (DA-2n, 2n = 2, 4, 6 or 8 referring to the number of oxethyl units per molecule), were blended with PVC. It was found that the tensile properties, transparency, and thermal stability of plasticized PVC (PVC-DA-2n) increased significantly with an increase in the number of oxyethyl units. Fourier-transform infrared spectroscopy analysis revealed that its good compatibility can be attributed to the strong interaction between oxyethyl units and PVC. As the number of the oxyethyl units of plasticizer increased, the glass transition temperature (T_g) of the corresponding plasticized PVC samples decreased from 62.3 (PVC-DA-2) to 35.4 °C (PVC-DA-8). Owing to the excellent plasticization of DA-8, the performances of PVC-DA-8 were comparable or better than that of the PVC plasticized using commercial dioctyl terephthalate (DOTP). The simple but efficient method of this study provides a new avenue for the preparation of vegetable oil-based plasticizers for PVC.

Designing Rosin-Based Plasticizers: Effect of Differently Branched Chains on Plasticization Performance and Solvent Resistance of Flexible Poly(vinyl chloride) Films

In the present study, we report a strategy to prepare rosin-based plasticizers with differently branched chains, which have the same benzene ring and similar alkane structure compared to phthalate plasticizers. Castor oil methyl ester, cardanol, and triethyl citrate were reacted with the chemical structure of rosin-based plasticizers. Rosin-based plasticizers with differently branched chains as alternative plasticizers for preparing phthalate-free flexible poly(vinyl chloride) films. All rosin-based plasticizers exhibited more excellent solvent extraction performance than phthalate plasticizers in four different solvents. The plasticizing efficiency of rosin-based plasticizers containing triethyl citrate groups reached 85.5%. The relationships between plasticizing efficiency, thermal stability, solvent resistance, tensile properties, and relative molecular mass of the branched chains of rosin-based plasticizers were investigated.

Degradation of PVC waste into a flexible polymer by chemical modification using DINP moieties

We propose a chemical modification method to produce flexible PVC with DINP moieties.

The emerging applications of click chemistry reactions in the modification of industrial polymers

Click chemistry reactions have been applied to the modification of major industrial polymers by analysing the synthetic approaches and the resulting material properties.

A rapid one-step surface functionalization of polyvinyl chloride by combining click sulfur(vi)-fluoride exchange with benzophenone photochemistry

We demonstrated a rapid one-step strategy for polyvinyl chloride surface functionalization by combining click “sulfur(vi)-fluoride exchange” (SuFEx) reaction with benzophenone photochemistry.

Plasticizers Derived from Biomass Resources: A Short Review

With rising environmental concerns and depletion of petrochemical resources, biomass-based chemicals have been paid more attention. Polyvinyl chloride (PVC) plasticizers derived from biomass resources (vegetable oil, cardanol, vegetable fatty acid, glycerol and citric acid) have been widely studied to replace petroleum-based o-phthalate plasticizers. These bio-based plasticizers mainly include epoxidized plasticizer, polyester plasticizer, macromolecular plasticizer, flame retardant plasticizer, citric acid ester plasticizer, glyceryl ester plasticizer and internal plasticizer. Bio-based plasticizers with the advantages of renewability, degradability, hypotoxicity, excellent solvent resistant extraction and plasticizing performances make them potential to replace o-phthalate plasticizers partially or totally. In this review, we classify different types of bio-based plasticizers according to their chemical structure and function, and highlight recent advances in multifunctional applications of bio-based plasticizers in PVC products. This study will increase the interest of researchers in bio-based plasticizers and the development of new ideas in this field.

Reactive cycloalkane plasticizers covalently linked to energetic polyurethane binders via facile control of an in situ Cu-free azide–alkyne 1,3-dipolar cycloaddition reaction

The kinetic performance of a spacer-controlled Huisgen azide–alkyne cycloaddition reaction for alkyne-bearing reactive cycloalkane plasticizers is explored in combination with the computational protocol.

Cardanol Groups Grafted on Poly(vinyl chloride)-Synthesis, Performance and Plasticization Mechanism

Internally plasticized poly(vinyl chloride) (PVC) materials are investigated via grafting of propargyl ether cardanol (PEC). The chemical structure of the materials was studied by FT-IR and ¹H NMR. The performace of the obtained internally plasticized PVC materials was also investigated with TGA, DSC and leaching tests. The results showed that grafting of propargyl ether cardanol (PEC) on PVC increased the free volume and distance of PVC chains, which efficiently decreased the glass transition temperature (Tg). No migration was found in the leaching tests for internally plasticized PVC films compared with plasticized PVC materials with commercial plasticizer dioctyl phthalate (DOP). The internal plasticization mechanism was also disscussed according to lubrication theory and free volume theory. This work provides a meaningful strategy for designing no-migration PVC materials by introducing cardanol groups as branched chains.

Flexible Poly(vinyl chloride) Nanocomposites Reinforced with Hyperbranched Polyglycerol-Functionalized Graphene Oxide for Enhanced Gas Barrier Performance

Herein, we describe the preparation of flexible poly(vinyl chloride) (PVC) containing hyperbranched polyglycerol (HPG)-functionalized graphene oxide (HGO) as a reinforcing filler and reveal that the obtained composites exhibit greatly improved gas barrier properties. Moreover, we show that HGO, synthesized by surface-initiated ring-opening polymerization of glycidol followed by esterification with butyric anhydride, exists as individual exfoliated nanosheets possessing abundant functional groups capable of interacting with PVC. A comparative study of butyl-terminated graphene oxide (BGO) reveals that functionalization with HPG is of key importance for achieving a uniform dispersion of HGO in the PVC matrix and results in strong interfacial interactions between HGO and PVC. As a result, flexible PVC/HGO nanocomposite films exhibit significantly enhanced tensile strength and toughness compared to those of neat plasticized PVC while maintaining its inherent stretchability. Furthermore, the two-dimensional planar structure and homogeneous distribution of HGO in PVC/HGO nanocomposites make gas molecules follow a highly tortuous path, resulting in remarkably reduced oxygen permeability, which is more than 60% lower than that of neat plasticized PVC. Consequently, HGO is demonstrated to be promising component of flexible and gas-impermeable PVC films for a wide range of applications.

Nonmigrating Equivalent Substitutes for PVC/DOP Formulations as Shown by a TG Study of PVC with Covalently Bound PEO-PPO Oligomers

Monoamino functionalized ethylenoxide (EO)/propylenoxide oligomers (Jeffamine) are linked chemically to poly(vinyl chloride) (PVC) using trichlorotriazine chemistry in order to prepare nonmigrating internally plasticized materials. The dependence of the plasticizer efficiency on both the number of anchoring points to the chains and the PVC/plasticizer compatibility is investigated using oligomers of different molecular weight and hydrophilic-hydrophobic balance. Hydrophilic oligomers (containing predominantly EO) of molecular weights between 2000 and 5000 g mol^-1 exhibit excellent plasticizer efficiency, nearly identical to di-2-ethylhexylphthalate (DOP) in conventional PVC/DOP mixtures and may therefore be used as nonmigrating equivalents for DOP.

Internally plasticized PVC materials via covalent attachment of aminated tung oil methyl ester

We developed an internal plasticizer of aminated tung oil methyl ester for the production of non-migration, phthalate-free flexible and internally plasticized poly(vinyl chloride) (PVC) materials.