Characterisation and tanning effects of purified chestnut and sulfited quebracho extracts.

Unlabelled: Vegetable tannins are environmentally friendly tanning agents. However, they generally impart a dark colour to the tanned leather and highly contribute to the organic load in wastewaters. In this study, we employed a purification protocol separately on chestnut tannin (CT) and sulfited quebracho tannin (QT) to obtain the purified fractions (PCT and PQT).

Enhanced Antibacterial Activity of Vancomycin Loaded on Functionalized Polyketones.

Today, polymeric drug delivery systems (DDS) appear as an interesting solution against bacterial resistance, having great advantages such as low toxicity, biocompatibility, and biodegradability. In this work, two polyketones (PK) have been post-functionalized with sodium taurinate (PKT) or potassium sulfanilate (PKSK) and employed as carriers for Vancomycin against bacterial infections. Modified PKs were easily prepared by the Paal-Knorr reaction and loaded with Vancomycin at a variable pH.

Use of carboxymethyl cellulose as binder for the production of water-soluble catalysts.

Bio-based polymers are materials of high interest given the harmful environmental impact that involves the use of non-biodegradable fossil products for industrial applications. These materials are also particularly interesting as bio-based ligands for the preparation of metal nanoparticles (MNPs), employed as catalysts for the synthesis of high value chemicals. In the present study, Ru (0) and Rh(0) Metal Nanoparticles supported on Sodium Carboxymethyl cellulose (MNP(0)s-CMCNa) were prepared by simply mixing RhClx3HO or RuCl with an aqueous solution of CMCNa, followed by NaBH reduction.

Mechanical and Physical Changes in Bio-Polybutylene-Succinate Induced by UVC Ray Photodegradation.

Bio-polybutylene succinate (PBS) is a biodegradable polymer obtained from renewable feedstock having physical-mechanical properties like traditional low-density polyethylene (LDPE). PBS is employed by many manufacturing sectors, from biomedical to agri-food and cosmetics. Although some studies have already evaluated the resistance of PBS to photodegradation caused by natural outdoor solar exposure (UVA-UVB), a systematic study on the resistance to degradation caused by exposure to UVC rays, which is the subject of this study, has not yet been carried out.

Chitosan as a Bio-Based Ligand for the Production of Hydrogenation Catalysts.

Bio-based polymers are attracting increasing interest as alternatives to harmful and environmentally concerning non-biodegradable fossil-based products. In particular, bio-based polymers may be employed as ligands for the preparation of metal nanoparticles (M(0)NPs). In this study, chitosan (CS) was used for the stabilization of Ru(0) and Rh(0) metal nanoparticles (MNPs), prepared by simply mixing RhCl × 3HO or RuCl with an aqueous solution of CS, followed by NaBH reduction.

Waste Cooking Oil as Eco-Friendly Rejuvenator for Reclaimed Asphalt Pavement.

Over 50 MioT of Waste Cooking Oil (WCO) was collected worldwide in 2020 from domestic and industrial activities, constituting a potential hazard for both water and land environments, and requiring appropriate disposal management strategies. In line with the principles of circular economy and eco-design, in this paper an innovative methodology for the valorisation of WCO as a rejuvenating agent for bitumen 50/70 coming from Reclaimed Asphalt Pavement (RAP) is reported. In particular, WCO or hydrolysed WCO (HWCO) was modified by transesterification or amidation reactions to achieve various WCO esters and amides.

May 1,3,5-Triazine derivatives be the future of leather tanning? A critical review.

Leather is produced by a multi-step process among which the tanning phase is the most relevant, transforming animal skin collagen into a stable, non-putrescible material used to produce a variety of different goods, for the footwear, automotive, garments, and sports industry. Most of the leather produced today is tanned with chromium (III) salts or alternatively with aldehydes or synthetic tannins, generating high environmental concern. Over the years, high exhaustion tanning systems have been developed to reduce the environmental impact of chromium salts, which nevertheless do not avoid the use of metals.

Plastics today: Key challenges and EU strategies towards carbon neutrality: A review.

Never as today the need for collaborative interactions between industry, the scientific community, NGOs, policy makers and citizens has become crucial for the development of shared political choices and protection of the environment, for the safeguard of future generations. The complex socio-economic and environmental interconnections that underlie the EU strategy of the last years, within the framework of the Agenda 2030 and the green deal, often create perplexity and confusion that make difficult to outline the definition of a common path to achieve carbon neutrality and "net zero emissions" by 2050. Scope of this work is to give a general overview of EU policies, directives, regulations, and laws concerning polymers and plastic manufacturing, aiming to reduce plastic pollution, allowing for a better understanding of the implications that environmental concern and protection may generate from a social-economical point of view.

Agri-Food Wastes for Bioplastics: European Prospective on Possible Applications in Their Second Life for a Circular Economy.

Agri-food wastes (such as brewer's spent grain, olive pomace, residual pulp from fruit juice production, etc.) are produced annually in very high quantities posing a serious problem, both environmentally and economically. These wastes can be used as secondary starting materials to produce value-added goods within the principles of the circular economy.

Boosting physical-mechanical properties of adipic acid/chitosan films by DMTMM cross-linking.

In this paper we present a novel strategy to easily prepare biodegradable chitosan derived films as new packaging systems. Combination of chitosan, adipic acid and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM) allowed to obtain high-performing cross-linked films. Biobased glycerol was employed as plasticizer.

Sustainable triazine-derived quaternary ammonium salts as antimicrobial agents.

The first examples of highly efficient antimicrobial triazine-derived bis imidazolium quaternary ammonium salts (TQAS) are reported. TQAS have been prepared with an easy, atom efficient, economically sustainable strategy and tested as antimicrobial agents, reaching MIC values below 10 mg L. Distinctively, TQAS have low MIC and low cytotoxicity.

Recent Advancements in Plastic Packaging Recycling: A Mini-Review.

Today, the scientific community is facing crucial challenges in delivering a healthier world for future generations. Among these, the quest for circular and sustainable approaches for plastic recycling is one of the most demanding for several reasons. Indeed, the massive use of plastic materials over the last century has generated large amounts of long-lasting waste, which, for much time, has not been object of adequate recovery and disposal politics.

Synthesis and Antimicrobial Evaluation of Bis-morpholine Triazine Quaternary Ammonium Salts.

Efficient, environmentally and economically sustainable, and nontoxic antibacterial products are of global relevance in the fight against microorganism contamination. In this work, an easy and straightforward method for the synthesis of bis-morpholino triazine quaternary ammonium salts (bis-mTQAS) is reported, starting from 2,4,6-trichloro-1,3,5-triazine or 2,4-dichloro-6-methoxy-1,3,5-triazine and various N-alkylmorpholines. Bis-mTQAS were tested as antimicrobials against Gram-negative and Gram-positive bacterial strains.

Efficient Triazine Derivatives for Collagenous Materials Stabilization.

Nowadays, the need to reduce plastic waste and scantly biodegradable fossil-based products is of great importance. The use of leather as an alternative to synthetic materials is gaining renewed interest, but it is fundamental that any alternative to plastic-based materials should not generate an additional environmental burden. In the present work, a simple protocol for collagen stabilization mediated by 2-chloro-4,6-diethoxy-1,3,5-triazine (CDET) and a -amine has been described.

Sustainable Triazine-Based Dehydro-Condensation Agents for Amide Synthesis.

Conventional methods employed today for the synthesis of amides often lack of economic and environmental sustainability. Triazine-derived quaternary ammonium salts, e.g.

Development of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride cross-linked carboxymethyl cellulose films.

First example of the use of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM) as cross-linking agent for the development of carboxymethyl cellulose (CMC) films for food packaging is reported. Influence of different wt % of DMTMM and glycerol on the physical-mechanical properties of CMC films was investigated. The presence of DMTMM effectively improved moisture uptake, moisture content, water vapour permeability, water solubility of the films, oil resistance together with good biodegradability.

Polyamidoamide Dendrimers and Cross-Linking Agents for Stabilized Bioenzymatic Resistant Metal-Free Bovine Collagen.

The work reports the use of polyamidoamine dendrimers (PAMAM) and a cross-linking agent, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/-hydroxysuccinimide (EDC/NHS) or 4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM), for the thermal stabilization of dermal bovine collagen. The efficiency of EDC/NHS/PAMAM and DMTMM/PAMAM in the cross-linking of collagen is correlated to the increase of the collagen shrinkage temperature (Ts), measured by differential scanning calorimetry (DSC). An alternative enzymatic protocol was adopted to measure the degradability of EDC/NHS/PAMAM tanned hides; these data are correlated to the thermal stability values measured by DSC.

Synthesis, characterization and catalytic activity of novel ruthenium complexes bearing NNN click based ligands.

Novel air stable ruthenium(ii) complexes bearing tridentate ligands bis((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)amine (L1), 1-(1-benzyl-1H-1,2,3-triazol-4-yl)-N-(pyridin-2-ylmethyl)methanamine (L2) or 2-(4-phenyl-1H-1,2,3-triazol-1-yl)-N-(pyridin-2-ylmethyl)ethan-1-amine (L3) were synthesised. The nitrogen based ligands were easily prepared by virtue of click chemistry using cheap and commercially available reagents. The ruthenium complexes were obtained by heating the Ru(PPh3)3Cl2 precursor and the tridentate NNN ligand in toluene under reflux for 2 hours, achieving yields of 82-87%.

Efficient Chemo-Enzymatic Transformation of Animal Biomass Waste for Eco-Friendly Leather Production.

Enzymatically processed animal biomass derived from treated bovine hides (wet blue scraps) is herein used as building block for the synthesis of a novel biopolymer. An enzymatic hydrolysis process allows to produce water-soluble lower molecular weight proteins (Bio-A), which are then reacted with glycerol and maleic anhydride (MA) in order to obtain a new intermediate (Bio-IA). With Bio-IA in hand, co-polymerization in the presence of acrylic acid is then carried out.

An alternative stereoselective synthesis of (R)- and (S)-Rosaphen® via asymmetric catalytic hydrogenation.

We report an alternative synthesis of the two enantiomers of the floral fragrance Rosaphen®. The key intermediate 2-methyl-5-phenylpentanoic acid 3 is synthesized via asymmetric hydrogenation (ee up to 99%) in the presence of an in situ prepared ruthenium catalyst containing the chiral ferrocenyl phosphine Mandyphos-4.