Academic literature on the topic 'Bio-plasticizer'

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.

This study aims to determine the effect of the type and concentration of plasticizers and their interactions on the characteristics of the taro potato starch bio-plastic composite and to determine the type and concentration of the plasticizer that produces the best characteristic of the taro starch bio-plastic composite. This study used a factorial randomized block design. The first factor is the type of plasticizer which consists of 4 levels, namely glycerol, sorbitol, castor oil, and stearic acid. The second factor is the concentration of plasticizers with 4 levels, namely 0.5%; 1%; 1.5%; 2%. Each treatment was grouped into 2 based on the time of making bio-plastics, so there were 32 experimental units. The variables observed were tensile strength, elongation at break, elasticity, thickness expansion, water vapor transmission rate, and biodegradation. The data obtained were analyzed for diversity and continued with the Honest Significant Difference test. The results showed that the type and concentration of plasticizers and their interactions had a very significant effect on tensile strength, elasticity, thickness expansion and water vapor transmission rate. The type of plasticizer and the concentration of the plasticizer have a very significant effect, while the interaction has no significant effect on elongation at break. The type of plasticizer and the concentration of the plasticizer and their interactions have no significant effect on biodegradation. The best characteristics of bio-plastic composites occurred when using stearic acid plasticizer with a concentration of 0.5% with a tensile strength value of 23.00 MPa, elongation at break 2.22%, elasticity 1038.27 MPa, expansion 91.47%, water vapor transmission rate 1.38 g/m2.hour and 7 days of degradation. The bioplastics produced in this study have met the standards of SNI 7818:2014 on the variable tensile strength, elasticity and international standards ASTM 5336 on the variable length of degradation. Key words: taro tuber starch, chitosan, composites bio-plastic, type and concentration of plasticizer.

HighlightsThermo-physical characterization of two types of Kraft lignin mixed with three bio-plasticizer.Crude glycerol showed the greater depression in melting point with its increasing proportion.The acidic lignin has more tensile strength and density than the alkaline lignin.Micro-pores of the lignin pellet were minimized by adding bio-plasticizer.Abstract. Kraft lignin, a by-product of the paper industry, is well known for its binding properties, enabling its use in the production of pellets and briquettes from biomass. Different bio-plasticizers, by-products from the vegetable oil processing industry, could serve as plasticizers for biomass briquettes. The properties of three bio-plasticizers (glycerol, fatty acid, and biodiesel), when mixed with isolated Kraft lignin, were studied to identify their potential application as efficient binders for biomass briquettes. The phase transition characteristics (glass transition, pre-melting crystallization, and melting) of two types of isolated lignin samples (acidic and alkaline) and lignin-plasticizer mixtures were determined using a differential scanning calorimeter. The mechanical (tensile strength) and physical (density) characteristics of the compacted cylindrical lignin pellets were tested. The spatial distribution of micropores in the lignin pellets was studied using x-ray tomography. Even though an overlap was observed in the glass transition temperatures of the mixtures, a significant depression in the pre-melting crystallization and melting temperatures was observed for both lignin samples containing elevated concentrations of the bio-plasticizers, and the highest tensile strength was obtained for pellets with 10% bio-plasticizer. Among the three bio-plasticizers, crude glycerol showed the greatest depression in melting point with increasing proportions of both acidic lignin (60.7°C ±2°C) and alkaline lignin (85.1°C ±2°C). In general, alkaline lignin showed some limitations over acidic lignin in the tensile strength of the pellets as well as their fusion temperature, even though the addition of a bio-plasticizer improved the strength and depressed the melting point in both lignin-based samples. Keywords: Bio-plasticizer, Lignin, Mechanical properties, Microstructure, Phase transition.

An all-inclusive bio-chemical route from the fermentation process to downstream process for C5 plasticizer synthesis was developed using fermentation-derived glutaric acid produced by metabolically engineered Corynebacterium glutamicum.

Abstract A polyester plasticizer (RSOP) for polyvinyl chloride based on rubber seed oil (RSO) was synthesized. Firstly, RSO monoglyceride were synthesized by the transesterification of RSO with glycerol at 220–240 °C. Secondly, RSOP was synthesized from RSO monoglyceride and adipic acid by esterification. The polyester plasticizer was characterized by GPC, FT-IR, 1H NMR and DSC. Plasticized polyvinyl chloride (PVC) materials with RSOP and dioctyl phthalate (DOP) in varying ratios were prepared via thermal melting process, RSOP was used as a second plasticizer. The properties of the plasticized PVC materials were characterized by a universal testing machine, TGA, DMA and solvent extraction resistance. The obtained PVC materials showed improved thermal stability and lower glass transition temperature than PVC. Solvent extraction resistance and plasticization of plasticized PVC were also improved. This study provides a new strategy for preparing bio-based polyester plasticizer from RSO.

ABSTRACT Bio-based oil is an emerging oil source to replace petroleum oil products in elastomers as a plasticizer. It is renewable, low cost, and has many advantages over conventional petroleum plasticizers. Bio-based oil usually contains multiple functional groups and can be treated, modified, or polymerized for different applications. In this article, a brief overview of bio-based oil and such replacement is provided. An example of modified soybean oil used in carbon black–filled SBR compounds is discussed to show the change brought about by the use of bio-based oils.

Plasticizers are generally added to cosmetic and personal care products to improve the filmforming abilities of the product and increase flexibility of the film formed on the skin or hair surface. For example, plasticizers are present in perfumes to prolong the release of the specific scent, which is the ultimate goal in a good quality perfume. Plasticizers in nail varnishes prevent chipping, improve the aesthetics by adhering to the keratin in the nail which means the coating stays on for much longer, which is the ultimate goal in nail products. Plasticizers improve the gloss, resist chipping and allow quick drying time. Therefore it can be seen that plasticizers play a vital role in personal care products like perfumes and nail varnishes. Certain plasticizers e.g. phthalates, can cause problems associated with human health and can harm the environment. They are easily available and large volumes can be obtained at a low cost. These phthalates, for example, di-butyl phthalate (DBP) have been identified as carcinogenic. Nowadays the occurrence of cancer is rapidly increasing. The plasticizers present in a large number of consumer and personal care products, can possibly be linked to the ever increasing reports of cancer. Therefore a substitute to the traditional phthalate plasticizers must be investigated. The aim of this research is to produce a plasticizer derived from naturally occurring Eucalyptus oil, which can be used to replace the existing plasticizers in cosmetic formulations. Para-menthane-3,8-diol (PMD), occurring naturally in the oil from the tree, Eucalyptus citriodora, forms an acetal with citronellal (PMD, acetal, citronellal all occur naturally in the oil). It has been previously shown that PMD-citronellal acetal will exhibit plasticizing properties similar to conventional plasticizers. The objective was to enhance the formation of the acetal in the Eucalyptus oil by reacting it with excess PMD. An effective synthesis method for the PMD-citronellal acetal enriched oil (~73.8 percent) was determined from optimization experiments. The physical characterisation of the PMD-citronellal acetal enriched oil was done and compared with that of DBP. The acetal-enriched oil had a lower density, slightly higher solubility in water (at 25°C), lower refractive index (Brix percent) and a higher boiling point (350°C) than DBP. The physical characteristics of the Eucalyptus oil source and the acetal-enriched Eucalyptus oil were very similar. This can be expected as the Eucalyptus oil consists of ~84.3 percent Citronellal, ~ 1.3 percent PMD and 2.7 percent PMD-citronellal acetal. In this study the effectiveness of the acetal-enriched Eucalyptus oil (referred to from now on as the bio-plasticizer) was compared to a conventional plasticizer such as di-butyl phthalate (DBP), commonly used in cosmetic products. Two cosmetic formulations were produced: a nail varnish and a perfume formulation. Various tests were performed on these formulations to investigate the plasticizing properties of the bio-plasticizer. The objectives were to determine if the natural plasticizer is as effective as the potentially carcinogenic phthalate plasticizers and can be used as a substitute for the phthalates in personal care products. The results indicate that the bio-plasticizer does behave similarly to di-butyl phthalate, however, the effectiveness of the bio-plasticizer is lower than that of di-butyl phthalate. As the viscosity of the synthesized oil was high, this affected the overall consistency of the products. A more viscous nail varnish and perfume was produced in comparison to the DBP counterpart. The stability of the bio-plasticizer in the cosmetic formulations of nail varnish and perfume was also investigated. The cosmetic products were incubated at 0°C, 25°C and 40°C over a period of two months. Any changes in colour, odour, pH, refractive index, separation and plasticizer peak change in the gas chromatogram trace were recorded. It was determined that the PMD-citronellal acetal-enriched oil was relatively unstable under elevated temperatures and light intensity. Storage under higher temperatures (40°C) tends to increase the acidity. Therefore the bio-plasticizer must be placed in a closed, covered bottle and stored in an environment away from light and elevated temperatures. According to the gas chromatogram peaks, it was clear that both the bio-plasticizer and the DBP were more unstable in the perfume formulation than in the nail polish and were especially sensitive to light when in the perfume. This could possibly be due to the interaction with the fragrance molecule, p-anisaldehyde.

L’un des défis majeurs dans le domaine des polymères est la substitution des molécules pétro-sourcées en vue de l’élaboration de monomères, polymères et d'additifs pour polymères. Le travail de cette thèse s’axe sur la valorisation de molécules bio-sourcées et plus particulièrement, du cardanol et de dérivés d'huiles végétales. Le champ d’application des polymères étant large, nous avons choisi de nous centrer sur trois grandes problématiques.Dans un premier temps, nous nous sommes intéressés à la plastification du PVC qui, actuellement, est majoritairement réalisée par des phtalates, famille d’esters pétro-sourcés vivement suspectés d’être des perturbateurs endocriniens. Des additifs de substitution ont ainsi été synthétisés par une chimie simple à partir du cardanol et d’esters gras. Des stabilités thermiques et des propriétés plastifiantes très satisfaisantes ont été obtenues. Enfin, des tests de toxicité et d’écotoxicité ont démontré l’absence d'impact perturbateur sur la sécrétion d'hormones sexuelles et la non toxicité vis-à-vis de l'environnement de ces plastifiants bio-sourcés.Dans un second temps, nous avons revisité la chimie des résines phénoplastes habituellement préparées à partir du phénol et du formaldéhyde, deux molécules classées CMR. Nous avons adapté cette chimie robuste à un phénol bio-sourcé, le cardanol, et à un aldéhyde bio-sourcé, le nonanal, pour obtenir des résines phénoliques souples. Cette propriété recherchée est le résultat d’une plastification interne des chaines lipidiques pendantes au sein du réseau polymère. Par cet exemple, l’intérêt des dérivés d’huiles végétales pour l’élaboration de matériaux souples a été démontré. Un compromis entre la souplesse des résines phénoliques et leurs résistances chimique et thermique a été atteint.Enfin, nous nous sommes tournés vers l’élaboration de polyuréthanes réticulés à partir d’un ester gras, d’un diester gras et d’un triglycéride porteurs de fonctions alpha-hydroxycétone (collaboration avec l’équipe CASYEN de l’ICBMS). L’apport de la fonction alpha-cétone sur la réactivité du polyol vis-à-vis du réactif isocyanate n’est que modeste par rapport à des dérivés présentant un groupement alcool isolé sur la chaine (huile de ricin) et alcool associé à une autre fonction alcool (triglycéride 1,2-diol). Néanmoins, la présence d’interactions intramoléculaires provenant des groupements cétone a permis d’exacerber la stabilité thermique des matériaux PU et d’élaborer des PU réticulés souples par plastification interne comme dans le cas des résines phénoliques.Cette thèse a ainsi démontré l’apport des phénols lipidiques tels que le cardanol et des chaines grasses dans l’amélioration de la stabilité thermique et de la souplesse au sein de matériaux polymères
One of the major challenges in the field of polymers is the substitution of oil-based molecules for the development of monomers, polymers and polymer additives. The topic of this thesis is focused on the valorization of bio-sourced molecules and particularly, cardanol and vegetable oil derivatives. Since the scope of polymers is broad, we have chosen to focus on the following three major issues.At first, we were interested in the plasticization of PVC, which is most often carried out by phthalates, a family of oil-based esters strongly suspected to be endocrine disruptors. Alternative additives were thus synthesized by simple chemical reactions from cardanol and fatty esters. Good thermal stabilities and satisfactory plasticizing properties were obtained. Finally, toxicity and ecotoxicity tests have demonstrated the absence of a disruptive impact on the secretion of sex hormones and the non-toxicity towards the environment of these bio-sourced plasticizers.In a second step, we were interested in the chemistry of phenolic resins usually prepared from phenol and formaldehyde, two molecules classified as CMR substances. Thus, a bio-sourced phenol, cardanol, and a bio-sourced aldehyde, nonanal, were reacted to reach flexible phenolic resins. This peculiar property is the result of internal plasticization of the pendant lipid chains within the polymer network. By this example, the interest of vegetable oil derivatives for the production of flexible materials was demonstrated. Finally, a compromise between the flexibility of phenolic resins and their chemical and thermal resistances was reached.Finally, we turned to the development of crosslinked polyurethanes from a fatty ester, a fatty diester and a triglyceride exhibiting alpha-hydroxyketone functions (collaboration with the CASYEN team of the ICBMS). The contribution of the alpha-ketone function on the reactivity of the related to the isocyanate reagent is only modest compared to isolated alcohol type derivatives (castor oil) and alcohol associated with another alcohol function ( triglyceride 1,2-diol). Nevertheless, the presence of intramolecular interactions from ketone groups made possible to enhance the thermal stability of the PU materials and to develop flexible crosslinked PUs by internal plasticization, as in the case of phenolic resins.This thesis brings out the advantages provided by the use of lipid phenols such as cardanol and fatty chains for the improvement of thermal stability and flexibility of polymer materials

Master of Science
Department of Grain Science and Industry
Xiuzhi Susan Sun
Soybean oil-based resin for transparent flexible coating applications were formulated by dihydroxyl soybean oil (DSO) with commercial epoxy monomers (i.e., epoxidized soybean oil (ESO) and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECHM)). The resin was formed to thermoset polymers using cationic ring-opening photopolymerization. The ether crosslinking and post-polymerization of the polymeric network were observed using Fourier transform infrared spectroscopy. Thermal properties of the bio-based coating materials and their copolymerization behaviors were examined using a differential scanning calorimetry and a thermogravimetric analyzer. Crosslink density and molecular weight between crosslink were obtained from dynamic mechanical analysis. ECHM/DSO (1: 1.43 weight ratio) films showed the highest elongation at break (49.2 %) with a tensile strength of 13.7 MPa. After 2 months storage, the elongation at break and tensile strength of films were 32 % and 15.1 MPa, respectively. ESO/DSO films (w/w ratios of 1:0.1, 1:0.15, and 1:0.2) exhibited stable flexibility around 11-13 % of elongations at break without significant reductions of tensile strengths (2.5 to 4.4 MPa) during 2-months shelf life. Optical transparencies of the films were comparable to commercial glass and polymers, and water uptake properties (0.72 and 2.83%) were significantly low.

Per inquinamento causato dalle materie plastiche si intende l’accumulo in ambiente di prodotti plastici in grado di indurre problemi sia all’ambiente che alle specie selvatiche. Il Bisfenolo A (BPA) è uno dei distruttori endocrini maggiormente prodotti a livello mondiale durante la lavorazione della plastica. Numerosi studi hanno mostrato la capacità di questo inquinante di creare effetti dannosi sia sull’uomo che sulle specie selvatiche, per cui nel tempo sono stati compiuti diversi tentativi volti a trovare delle valide alternative. Tra i possibili sostituti, in questo studio di dottorato, l’attenzione è stata focalizzata sul Dhietylene dibenzoato (DGB) ed il Diisononilftalato (DiNP). Lo scopo principale di questo progetto è stato quindi quello di studiare l’impatto di questi plastificanti, focalizzando l’attenzione sui loro effetti nella riproduzione e nel metabolismo lipidico. Gli effetti del nonilfenolo, dell’ottilfenolo (t-OP) e del BPA sul metabolismo lipidico, sono stati inoltre analizzati in giovanili di orata. I risultati ottenuti hanno dimostrato come, sia il BPA, che il DiNP, siano in grado di interferire con il processo di oogenesi e che, sia il BPA che il DGB, sono in grado di interferire con il metabolismo lipidico nello zebrafish. La somministrazione a giovanili di orata di mangimi contaminati con diversi inquinanti tra cui il BPA, ha mostrato la loro capacità di indurre disordini metabolici, mostrando come oltre all’esposizione ambientale, anche il consumo di cibi contaminati possa essere considerata una fonte di esposizione importante ai contaminanti. Concludendo, il presente progetto di dottorato, mostra la capacità di alcuni distruttori endocrini, utilizzati nella lavorazione della plastica e nei detergenti, di interferire con la riproduzione ed il metabolismo lipidico nei teleostei, agendo prevalentemente in maniera dose dipendente, secondo curve non-monotoniche e, nel caso del BPA, interferendo con i meccanismi epigenetici.
Plastic pollution involves the accumulation of plastic products in the environment that adversely affects wildlife and wildlife habitat. Bisphenol A (BPA) is one of the highest volume endocrine disruptor produced worldwide during the manufacturing of plastic. Due to his well-documented detrimental effects, several substitute for BPA, but also for other plasticizer of common use, have been suggested, such as Diethylene glycol dibenzoate (DGB) and Diisononyl Phthalate (DiNP). The aim of this project is therefore to investigate the impact of several plasticizers, which are supposed to act as endocrine disruptor compounds (EDCs), focusing the attention on their effects on metabolic and reproductive system. Due to the necessity of testing a different range of concentrations in various plastic pollutants, an experimental model easy to reproduce, treat and analyse was needed; thus the choice to introduce zebrafish as experimental model for these studies. Concomitantly, the effects of nonylpnenol (NP), 4-tert-octylphenol (t-OP) and BPA on lipid metabolism were studied in sea bream juveniles. The results we obtained, using a multidisciplinary approach ranging from molecular to spectroscopic techniques, showed the ability of BPA and DiNP to interfere with female’s reproduction in a dose dependent manner. Concerning BPA its epigenetic effects were also demonstrated and eventually both BPA and DGB were found able to interfere with lipid metabolism in a dose dependent manner. Furthermore t-OP, NP and BPA were demonstrated to give rise to hepatic metabolic disorders in sea bream juveniles. In conclusion, the present PhD project, demonstrates that endocrine disruptors compounds, used in the manufacturing of plastics, are able to interfere with reproductive and metabolic system of teleost fish. Furthermore, we demonstrates the capacity of BPA to affect gene expression through the deregulation of epigenetic patterns.

In this work developments and innovative studies are proposed for the current biodiesel technology in order to make the whole productive process more efficient. In particular, three main aspects were deeply investigated, the oil deacidification, as a pre-step to the oil transesterification, working on the optimization of the operative parameters and developing a suitable kinetic model able to predict, in a wide range of concentrations and temperatures, the acid conversion and the eventual double phase system formation. Moreover, the extraction of carotenes from crude palm oil was investigated, focusing on finding the operative parameters that permitted its complete preservation. Experimental results showed that at the optimized condition these molecules were adsorbed on the catalyst, giving encouraging information regarding their extraction from crude oils. Secondly, the transesterification reaction was studied in a novel way, trying to overcome the mass limitation due to the low methanol solubility in oil using a suitable co-solvent and CaO as catalyst. Good results were obtained when THF was used, the biodiesel yield was comparable to the homogeneous catalyzed process. Finally, a possible improvement of biodiesel to valuable chemical was studied. In particular the synthesis of epoxidized biodiesel was firstly optimized and then performed on biodiesel and distilled biodiesel, obtaining with this latter substrate a product with an epoxide content comparable to a commercial product, giving positive suggestion for its application as bioplasticizer.

Glucose, as the most plentiful sugar in nature, is a renewable resource and possesses excellent record in health safety. Levulinic acid is a platform chemical which plays an important role  in  biomass transformation and reactive intermediates. Both glucose and levulinic acid can be produced by biomass conversion with green processing techno logies. Due to the rising needs for bio-based, eco-friendly and non-toxic plasticizers, glucose levulinates as bio­ plasticizers were synthesized from glucose and levulinic acid, by utilizing microwave radiation or conventional condensation reaction (direct-heating method ). Acid number for the reaction liquor was measured by acid-base titration to follow the decrease of acid groups due to the reaction and the trend in  the acid number within reaction time displayed the process of esterification and possible sensitivity of the reaction rate to reaction scale. It showed that microwave radiation had superior ability in  enhancing reaction speed but it was also more sensitive to reaction scale and generated more diverse prod ucts  than the direct-heating method. Besides, the process of reaction and formation  of ester  bonds was  followed  and confirmed by FT IR. The achieved levulinate products were extracted by 2-pro panol and ethyl acetate. The practices showed several serio us problems in 2-propanol extraction, including high dosage required  for  NaCl and solvent and difficulties in purification. The ethyl acetate proved to be a suitable solvent for this study and the  extrac ted  product s  from  the Con-24hrs  and Micro-3/4/5/6/7hrs  were  characterized  by  1H  NMR,  13C N :tvlR. and LDI-MS. The results from spectrum suggested the presence of GL,. and G J .'l. type of levulinates. That means the glucose levulinates were  successfully  synthesized  although  the  dehydration side reaction of glucose was inevitable leading to the generation of glucosidic bonds. In addition, BG (mixture of glucose and glycosidic levulinates) was evaluated by so lution casting of starch and PVC. In order to minimize the microbial contaminations in solution casting of  starch, a  modified  method  was raised and applied. The results showed that 40% BG had goo d miscibility with starch and the conclusion was further proved by DSC measurements, while the BG performed poor miscibility with  PVC.

Research Doctorate - Doctor of Philosophy (PhD)
The history of marine pollution can be traced back to the very beginning of human civilisation. Nevertheless, this issue did not raise serious concern until a threshold level was reached with devastating consequences for the marine ecosystem. In recent years, bio-indicator species have been gradually embraced as one of the most effective approaches to predict, monitor and assess marine contamination. The statistics acquired from biomonitoring not only facilitate determination of the biological significance of man-made hazardous substances on marine ecosystems but also establish an important foundation for marine wildlife conservation and public health management. The focal species in this PhD project is an Australian native marine invertebrate Galeolaria caespitosa, which is recognised as a potential bio-indicator species for coastal marine pollution and a model organism for use in laboratory toxicity tests, due to a number of remarkable life history characteristics it exhibits. According to a range of recent studies, the gametes of G. caespitosa, particularly its spermatozoa, and the processes of fertilisation, embryogenesis and larval development were susceptible to marine contaminants and could be utilised as sensitive indicators of pollutants in the immediate environment. Nevertheless, the reproductive biology of this species, particular the male reproductive system, has only been superficially described. This knowledge gap has created an opportunity to undertake a comprehensive investigation of reproduction and embryonic development in this species including the sensitivity of these processes to common environmental contaminants. (1) Utilising serial histological sections and electron microscopic techniques, the male reproductive system in G. caespitosa was reconstructed and the general pattern of spermatogenesis was established. This study for the first time established a comprehensive model of male reproductive system in polychaetes, with the function of each compartment being elucidated in detail. In addition, clear similarities were found between the male reproductive system in this simple invertebrate and human beings in terms of the structure and function.(2) As the differentiation of round spermatids in G. caespitosa took place in the germinal fluid without any physical support from nurse cells, spermiogenesis in this species was regarded as a convenient model for studying the underlying mechanisms of this complex differentiation process. Therefore, spermiogenesis was analysed in detail at the ultrastructural level and a preliminary study was performed to reproduce the differentiation of spermatids in vitro. This in vitro study revealed that the regulators of spermiogenesis in G. caespitosa were gender-specific and involved proteinaceous constituents thereby providing a basis for future studies addressing the molecular regulation of this complex differentiation process. (3) Exposure of spermatozoa to low levels of dibutyl phthalate (DBP) led to impaired embryogenesis and developmental abnormalities that adhered to a common pattern featuring asymmetrical division of the blastomeres. This study yielded important information on the mechanisms underlying DBP-induced embryonic arrest and abnormality, highlighting the reproductive toxicity that DBP exhibits towards the gametes of aquatic invertebrates and providing novel insights into the role that sperm centrioles play in early embryogenesis. (4) By examining the adverse effects of common marine pollutants on early embryogenesis, it was clear that the stress response of spermatozoa, which was reflected by defects in the subsequent embryogenesis, could be utilised as a sensitive indicator for detecting certain chemicals, such as bisphenol A, DBP and a range of alkylphenols.

Several environmental chemicals are classified as endocrine disrupting compounds (EDCs). Many of them have an effect on endocrine functions and the hormones that they secrete. Persistent organic contaminants (POPs), plasticisers (phthalates and adipates) and some trace metal elements particularly mercury are well known as EDCs. During this research, we were based on a multi-makers approach by combining physicochemical, microbiological, molecular and biological analyses (bioassays and biomarkers) using multidrug resistance bacteria to antibiotics such as environmental bioindicator and multi-matrix species (waters, sediments, plants, fishes) for a broad diagnosis of the contamination of the coast of Mahdia. The samples were collected during one year (April 2018 to March 2019) by a composite sampling technique. We started with a physical-chemical analysis of seawater samples and sediment extracts which showcased that the areas are highly qualified except Rejiche and Mellouleche coastal stations. The chromatographic analysis (DMA- 80, ICP-MS, GC-MS and GC-MS-MS) performed during this study made it possible to highlight the contamination of the dimension of Mahdia by trace elements, phthalates, adipates, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs), triphenyl phosphate (TPHP). Our results show that Posidonia leaves and fish tissues are more involved in this contamination. A microbiological study was carried out for the characterisation of the bacterial fauna showed a significant diversity with similar bacterial communities between the study areas using the DDGE technique. Indeed, a wide dissemination of resistant bacteria to antibiotics, some of which are pathogenic, has been demonstrated as a bioindicator of pollution using biochemical and molecular techniques. An in-vivo toxicological survey was performed on adult female rats for 21 days by intraperitoneal injection of environmental doses of plasticisers. This study recorded an alteration in biochemical biomarkers (oestrogen, progesterone, ASAT, ALAT, cholesterol, and APL) and modifications in the histological biomarkers in the endocrine glands (ovary, thyroid). Add to that, the use of the estrogenicity test (test YES) carried out on the coastal waters of the Mahdia Coast did not show any oestrogenic activity. Ecotoxicological tests were also realised on the samples of marine water. This study was able to demonstrate the acute toxicity of seawater using the growth test of Selenastrum capricornutum and Lepidium sativum and the test mobility of Daphnia magna, with the exception of the Microtus test. In the light of our results, this research appears to be an important scientific reference for the evaluation of the contamination of aquatic environments by endocrine disruptors in the context of biomonitoring.