19 research outputs found
Polystyrene-Free Chain Extenders for Recycled Poly(ethylene terephthalate)
Chain extenders are additives introduced to economically
and efficiently
restore the performance of recycled condensation polymers such as
poly(ethylene terephthalate). The most widely used commercial chain
extenders for recycled poly(ethylene terephthalate) (rPET) is the
Joncryl ADR (ADR) family of copolymers which are composed of styrene,
glycidyl methacrylate (GMA), and butyl acrylate (BA). However, polystyrene
is prone to degradation at higher temperatures. Thus, the aim of this
study was to create polystyrene-free chain extenders for rPET recycling.
Polystyrene-free chain extenders were synthesized via free radical
polymerization from GMA, BA, and acetylated hydroxyethyl methacrylate
(HEMA-Ac) or benzoylated hydroxyethyl methacrylate (HEMA-Bz) to enhance
the thermal and mechanical properties of rPET. These chain extenders
were analyzed by 1H NMR spectroscopy, size exclusion chromatography,
and differential scanning calorimetry. The chain extender (1 phr)
was then blended with rPET by melt reactive extrusion, resulting in
mechanical and thermal properties comparable to those of the commercial
chain extender ADR. These additives offer safe alternatives to ADR
and will enable the recycling of large volumes of rPET and other condensation
polymers without generating any harmful residual styrene
Clear Antismudge Unimolecular Coatings of Diblock Copolymers on Glass Plates
Two polyÂ[3-(triisopropyloxysilyl)Âpropyl
methacrylate]-<i>block</i>-polyÂ[2-(perfluorooctyl)Âethyl
methacrylate] (PIPSMA-<i>b</i>-PFOEMA) samples and one polyÂ(perfluoropropylene
oxide)-<i>block</i>-poly-[3-(triisopropyloxysilyl)Âpropyl
methacrylate] (PFPO-<i>b</i>-PIPSMA) sample were synthesized,
characterized, and used to coat glass plates. These coatings were
formed by evaporating a dilute polymer solution containing HCl, which
catalyzed PIPSMAâs solâgel chemistry. Polymer usage
was minimized by targeting at diblock copolymer unimolecular (brush)
layers that consisted of a solâgelled grafted PIPSMA layer
and an oil- and water-repellant fluorinated surface layer. Investigated
is the effect of varying the catalyst amount, polymer amount, as well
as block copolymer type and composition on the structure, morphology,
and oil- and water-repellency of the coatings. Under optimized conditions,
the prepared coatings were optically clear and resistant to writing
by a permanent marker. The markerâs trace was the faintest
on PFPO-<i>b</i>-PIPSMA coatings. In addition, the PFPO-<i>b</i>-PIPSMA coatings were far more wear-resistant than the
PIPSMA-<i>b</i>-PFOEMA coatings
Zein and PVOH-Based Bilayer Approach for Plastic-Free Repulpable and Biodegradable Oil- and Water-Resistant Paper as a Replacement for Single-Use Plastics
Development of a Preliminary Framework for the Reduction of Plastics in Packaging
Plastic packaging causes much waste, and its sustainability is receiving increasing attention. Companies have made efforts to mitigate the environmental impacts of packaging; however, plastic waste from packaging remains a big issue. This study builds a framework of factors that are important in helping companies reduce the amount of plastic in their packaging. The framework is based on findings from a literature review and five interviews with practitioners. The study found that to achieve a reduction of plastic in packaging, seven factors are imperative in the fuzzy-end stage of packaging design and development