A5024831372- Flame retardant materials and properties
- Synthesis and properties of polymers
- Polymer composites and self-healing
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- biodegradable polymer synthesis and properties
- Carbon dioxide utilization in catalysis
- Organometallic Complex Synthesis and Catalysis
- Synthesis and Characterization of Heterocyclic Compounds
- Toxic Organic Pollutants Impact
- Silicone and Siloxane Chemistry
- Synthetic Organic Chemistry Methods
- Epoxy Resin Curing Processes
- Advanced Polymer Synthesis and Characterization
- Fire dynamics and safety research
- Polymer Nanocomposites and Properties
- Electrospun Nanofibers in Biomedical Applications
- Photopolymerization techniques and applications
- Surface Modification and Superhydrophobicity
- Mass Spectrometry Techniques and Applications
- Advanced Photocatalysis Techniques
- Analytical Chemistry and Chromatography
- Aerogels and thermal insulation
- Bone Tissue Engineering Materials
- Covalent Organic Framework Applications
Swiss Federal Laboratories for Materials Science and Technology
2017-2024
University of St. Gallen
2019-2021
ZHAW Zurich University of Applied Sciences
2017-2019
Kiel University
1993-1994
University of Vienna
1991
Polymer aerogels are a promising, non-brittle alternative to silica aerogel, but limited by their very poor high-temperature stability. Polyimide is widely known for its high heat-resistance, however, degree of volume shrinkage common polyimide after exposure temperatures above 200 °C. Here, we present the aerogel-in-aerogel composites that comprise aerogel grains with nanoparticulate microstructure embedded in nanofibrous matrix. The mixing procedure and synthesis protocol were optimized...
The effect of the addition additives such as melamine (Mel), silica nanoparticles and a phosphorus-based compound, i.e. 3-(6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)propenamide (DA), on fire mechanical performance bisphenol A diglycidyl ether (DGEBA)-based epoxy resin cured with isophoronediamine has been investigated. UL 94-V0 classification was achieved for containing DA at 2 wt% phosphorus loading. However, nano particles necessary to avoid melt dripping. incorporation Mel promoted...
The development of reusable fire-safe polymers with a prolonged lifetime heralds the switch for transition towards circular economy. In this framework, we report novel phosphonated thermoset which is composed networked phosphonate esters containing both PC and PO bonds. Employing simple one-pot, two-step synthetic methodology, oxirane groups epoxy resin were partially reacted various amounts reactive bis H-phosphonate monomer, cured cycloaliphatic hardener to obtain multifunctional...
This study addresses very important aspects of the sustainable development new flame retardant materials: (i) preparation a novel (FR) additive from bio-resource, (ii) its use as FR in poly(lactic acid) (PLA) based composites and, (iii) vitro toxicity assessment FR. The synthesis this bio-based was achieved through phospha-Michael addition diphenylphosphine oxide (DPPO) and naturally occurring compound coumarin, yielding 4-(diphenylphosphoryl)chroman-2-one (CU-DPPO). flame-retarded CUDPPO...
A facile methodology to durably modify cellulose fibers by forming in-situ phosphine oxide macromolecular physical networks is developed in this work. Such were formed treating the with a mixture of Michael adducts [trivinyl (TVPO) and cyclic amines (piperazine 2,4,6-tri(piperazine-1-yl)-1,3,5-triazine)] followed click crosslinking reaction initiated dry heat, microwave, or steaming process. The network integrated within produce durable treatment against laundering. NMR SEM analysis treated...
A simple method is reported for the preparation of silver nanoparticle (AgNP) embedded pH-responsive hydrogel microparticle catalyst via Michael addition gelation and in-situ nitrate (AgNO3) reduction. The AgNP-hydrogel microsphere exhibited an efficient reduction pollutants like 4-Nitrophenol (4-NP) Congo red (CR) under acidic medium with turn over frequency (TOF) ~170 h–1 ~124 respectively. Interestingly, activity catalysts was turned-OFF a basic (≥ pH 12) due to deswelling matrix...
Following a waste-to-wealth approach, humic acid (HA) was exploited as flame retardant additive. The effect of its addition alone and in combination with urea (UR) ammonium polyphosphate (APP) on the thermal, fire, mechanical performances bisphenol A diglycidyl ether (DGEBA)-based epoxy resin modified (3-aminopropyl)-triethoxysilane (AP) cured aliphatic isophoronediamine (IDA) has been investigated. Unlike previous studies, UL 94-V-0 classification achieved for containing HA at 6 wt % APP...
Flame retardance of epoxy resins is usually imparted using suitable additives and/or properly modified curing agents. Herein, via a two-step green synthetic procedure, the chemical modification matrix with reactive silicon and phosphorus precursors explored to obtain nanocomposites intrinsic flame-retardant features. Nanoscale phase separation occurs in first step, forming an inverse micelle system which polar nanodomains act as nanoreactors for hydrolysis silanes (Si precursors), giving...
Flame-retarded polymers, such as polyester textiles and sheets, are attracting attention with regard to their sustainability. Mechanical recycling is currently the most frequently used technique for improving circularity of plastics. However, one complication mechanical associated (still) inevitable mixtures polymers additives, which can influence material stability significantly deteriorate properties recycled products. In this study, we aim specifically investigate interactions between...
The conception of epoxy thermosets with both reprocessability and flame retardancy delineates a new horizon in polymer science, offering material solution that is not only superior fire safety but also environment friendly. Herein, flame-retardant vitrimer (EV) was prepared using partially bio-based IADPPO (diphenylphosphine oxide itaconic anhydride) citric acid as curing reagents via solvent-free process. Their incorporation created covalent adaptable networks (CANs) the matrix which...
Chlorinated paraffins (CPs) are high production volume chemicals and ubiquitous environmental contaminants. CPs produced used as complex mixtures of polychlorinated n-alkanes containing thousands isomers, leading to demanding analytical challenges. Due their degree chlorination, have highly isotopic mass patterns that often overlap, even when applying resolution spectrometry. This is further complicated in the presence degradation products such chlorinated alkenes (CP-enes). CP-enes formed...
Silica-epoxy nanocomposites were prepared via an "in-situ" sol-gel synthesis process and a phosphorus (P) flame-retardant i.e. 6H-dibenz[c,e][1,2]oxaphosphorin,6-[(1-oxido-2,6,7-trioxa-1-phosphabicyclo[2.2.2]oct-4-yl)methoxy]-, 6-oxide (DP) melamine (Mel) further added to the matrix improve its fire performance. The main components of epoxy resin bisphenol A diglycidyl ether (DGEBA) isophorone diamine (IPDA) hardener. addition DP as well silica alone into system stopped melt dripping...
Traditional materials are being constantly replaced by synthetic polymers, most of which highly flammable. Epoxy resins versatile and among the important class due to their multiple crosslinking capacity endowed oxirane ring, applications ranging from adhesives aeronautics. This study investigates comparative effect three hardeners (aromatic, cycloaliphatic, aliphatic) addition an oligophosphonate on thermal behavior fire performance bisphenol A diglycidyl ether semi–interpenetrating polymer...
Partially aromatic polyamides owing to their excellent thermal stability are widely used in high temperature applications, however, like aliphatic counterparts, they readily flammable and more challenging process. In this work, several organophosphorus flame retardants were synthesized compounded with partially polyamide evaluated for processability, thermal, fire behaviour. The compounds containing a commercial retardant, Exolit® OP 1230 (EX), two new retardants, namely...
Poly(ethylene terephthalate) (PET) has wide usage in packaging and fiber industries thanks to its superior mechanical, thermal, barrier properties. It is also one of the "big five" recyclable plastics with well-established procedures. In many textile film products, flame retardants (FRs) are added PET for fire-safe applications. However, PET/FR products often not designed recycling, downgrade during thermomechanical recycling due polymer degradation. To address this issue, we study behavior...
Three novel alkyl sulfone bridged phosphorus (P) compounds namely 6,6′-(sulfonylbis(ethane-2,1-diyl))bis(dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (SEDOPO), sulfonylbis(ethane-2,1-diyl))bis(diphenylphosphine oxide) (SEDPPO), and tetraphenyl (sulfonyl bis(ethane-2,1-diyl)) bis(phosphonate) (SEDPP) (i.e. phosphine oxide, phosphinate phosphonate, respectively) were synthesized via a Michael addition reaction with good yields (≥ 85%) at 200-g scale. They exhibited thermal stability above 250 °C,...
A simple one-pot synthesis process for functionalized mesostructured silica nanoparticles (MSNP) is reported. The novel demonstrated the possibility to achieve MSNP with a surface area up 501 m2.g−1 using phosphonate based nonsilane precursor such as N, N´-bis[4,6-bis(diethylphosphono)-1,3,5-triazin-yl]-1,2-diaminoethane (ED). obtained by 20 mol% of ED achieved 80 and increasing content 30 resulted in m2.g−1. Zeta potential MSNPs (−65.5 70.0 mV) were much higher than nanoparticle (NP)...
We present a facile chemical method for converting HDPE waste into valuable long-chain dicarboxylic acids (LCDCAs), thus transforming polymer monomers potentially novel polyester synthesis.