The Future of Plasticizers: Biobased and Oligomeric

The deficiencies of popular phthalate plasticizers(ready migration from a polymer matrix into which they have been incorporated,flammability,environmental pollution,human health risks)have stimulated efforts to develop new effective,nonmigrating,low-cost,nontoxic replacements.In the main,these have been based on readilyavailable,nontoxic biobased precursors.Some,including those prepared from plant oils,have been generated from biomaterials themselves.However,the more numerous and generally more effective have been generated from discrete compounds produced from various biomaterials.Several structural features of effective plasticizers have been recognized.Polar functionality is required to assure compatibility with a wide range of polymeric materials,including poly(vinyl chloride)(PVC),the most heavily plasticized polymer.A branched structure greatly enhances the effectiveness of compounds used as plasticizers.An oligomeric structure may strongly limit or prevent migration from a polymer matrix.Hyperbranched oligomers of defined structure derived from the readilyavailable,inexpensive,nontoxic biomonomers,glycerol and adipic acid contain all these features and are excellent plasticizers.They contain ester functionality,are highly branched,and display a large number of end groups,all of which contribute to their effectiveness as plasticizers.

The effect of reactive plasticizer on viscoelastic and mechanical properties of solid rocket propellants based on different types of HTPB resin

Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.

From mice to humans:a need for comparable results in mammalian neuroplasticity

Brain plasticity-A universal tool with many variations:The study of brain plasticity has been gaining interest since almost a century and has now reached a huge amount of information(>80,000 results in PubMed).Overall,different types of plasticity,including stem cell-driven genesis of new neurons(adult neurogenesis),cells in arrested maturation(dormant neurons),neuro-glial and synaptic plasticity,can coexist and contribute to grant plastic changes in the brain,from a cellular to system level(Benedetti and Couillard-Despres,2022;Bonfanti et al.,2023).

Contribution of mechanical forces to structural synaptic plasticity:insights from 3D cellular motility mechanisms

Cells,tissues,and organs are constantly subjected to the action of mechanical forces from the extracellular environment-and the nervous system is no exception.Cell-intrinsic properties such as membrane lipid composition,abundance of mechanosensors,and cytoskeletal dynamics make cells more or less likely to sense these forces.Intrinsic and extrinsic cues are integrated by cells and this combined information determines the rate and dynamics of membrane protrusion growth or retraction(Yamada and Sixt,2019).Cell protrusions are extensions of the plasma membrane that play crucial roles in diverse contexts such as cell migration and neuronal synapse formation.In the nervous system,neurons are highly dynamic cells that can change the size and number of their pre-and postsynaptic elements(called synaptic boutons and dendritic spines,respectively),in response to changes in the levels of synaptic activity through a process called plasticity.Synaptic plasticity is a hallmark of the nervous system and is present throughout our lives,being required for functions like memory formation or the learning of new motor skills(Minegishi et al.,2023;Pillai and Franze,2024).

Research Progress of Environment Friendly Plasticizers for Cellulose Acetate Processing

Cellulose acetate(CA)is an important cellulose derivative that can undergo thermoplas-tic processing.Plasticizers can form stable hydrogen bonds with CA molecular chains,reducing intermolecular and intramolecular interactions,and play an important role in the melting processing of CA.In recent years,environmentally friendly plasticizers that are natural,non-toxic,odorless,low dissolution,and low migration have received increas-ing attention in plastic processing.This article reviews the research progress of environ-mentally friendly plasticizers such as natural plasticizers,ionic liquid plasticizers,citrate plasticizers,and polyethylene glycol plasticizers in the processing of cellulose acetate,and looks forward to the application prospects of environmentally friendly plasticizers.

Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.

The interaction between KIF21A and KANK1 regulates dendritic morphology and synapse plasticity in neurons

Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.

Practice patterns among ophthalmic surgeons in treating concomitant oculoplastic conditions in preoperative period:A questionnaire-based study

BACKGROUND Addressing oculoplastic conditions in the preoperative period ensures both the safety and functional success of any ophthalmic procedure.Some oculoplastic conditions,like nasolacrimal duct obstruction,have been extensively studied,whereas others,like eyelid malposition and thyroid eye disease,have received minimal or no research.AIM To investigate the current practice patterns among ophthalmologists while treating concomitant oculoplastic conditions before any subspecialty ophthalmic intervention.METHODS A cross-sectional survey was disseminated among ophthalmologists all over India.The survey included questions related to pre-operative evaluation,anaesthetic and surgical techniques preferred,post-operative care,the use of adjunctive therapies,and patient follow-up patterns.RESULTS A total of 180 ophthalmologists responded to the survey.Most practitioners(89%)felt that the ROPLAS test was sufficient during pre-operative evaluation before any subspecialty surgery was advised.The most common surgical techniques employed were lacrimal drainage procedures(Dacryocystorhinostomy)(63.3%),eyelid malposition repair(36.9%),and ptosis repair(58.7%).Post-operatively,47.7%of respondents emphasized that at least a 4-week gap should be maintained after lacrimal drainage procedures and eyelid surgeries.Sixty-seven percent of ophthalmologists felt that topical anaesthetic procedures should be preferred while performing ocular surgeries in thyroid eye disease patients.CONCLUSION Approximately 50%of ophthalmologists handle prevalent oculoplastic issues themselves,seeking the expertise of an oculoplastic surgeon under particular conditions.Many ophthalmologists still favor using ROPLAS as a preliminary screening method before proceeding with cataract surgery.Eyelid conditions and thyroid eye disease are not as commonly addressed before subspecialty procedures compared to issues like nasolacrimal duct obstruction and periocular infections.

Microplastic and nanoplastic exposure and risk of diabetes mellitus

The issue of plastic pollutants has become a growing concern.Both microplastics(MPs)(particle size<5 mm)and nanoplastics(NPs)(particle size<1μm)can cause DNA damage,cytotoxicity,and oxidative stress in various organisms.The primary known impacts of microplastic/nanoplastic are observed in the liver and respiratory system,leading to hepatotoxicity and chronic obstructive pulmonary disease.Although research on the effects of MPs and NPs on diabetes is still in its early stages,there are potential concerns.This editorial highlights the risk to diabetics from co-exposure to contaminants and MPs/NPs,supported by evidence from animal studies and the various chemical compositions of MPs/NPs.

Synthesis of aliphatic amidediol and used as a novel mixed plasticizer for thermoplastic starch

In this paper,aliphatic amidediol was synthesized and mixed with glycerol used as a plasticizer for preparing thermoplastic starch（AGPTPS）.The yield of aliphatic amidediol was 91%.FF-IR expressed that the mixture of aliphatic amidediol and glycerol formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch.By scanning electron microscope（SEM）native cornstarch granules were proved to transfer to a homogeneous continuous system.After being stored for a period time at room temperature,the mechanical properties of AGPTPS were also studied.As a mixed plasticizer,aliphatic amidediol and glycerol would be practical to extend TPS application scopes.

Thermoplastic Starch Prepared with Different Plasticizers: Relation between Degree of Plasticization and Properties

Ethylene glycol, glycerol, sorbitol, formamide, and urea were used as plasticizers for the preparation of thermoplastic starch（TPS） from corn starch. The properties of TPS were tested by analysis method. The results showed that TPSs were more highly plasticized with amines than alcohols. For the same type of plasticizer, the degree of plasticization decreased as the molecular weight of plasticizer increased. The relationship between plasticization degree and TPS properties was characterized and described by mechanical properties and water absorption. The experimental results showed that when the degree of plasticization increased, the tensile strength decreased and the elongation at breakage and water absorption increased.

Effect of Compounding of Sodium Tripolyphosphate and Super Plasticizers on the Hydration of α-calcium Sulfate Hemihydrate

The inhibition and its mechanism of sodium tripolyphosphate （STP） composited with super plasticizers （SPs） on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, electronic probe micro analysis （EPMA）, scanning electron microscopy （SEM） and differential scanning calorimeter （DSC） measurements. The experimental results show that compared with STP addition, compositing STP with polycarboxylate （PC） plasticizer, the final setting time is prolonged from 0.5h to 2hs. While formulating STP with naphthalene-based plasticizer （NAP） or sulfonate melamine formaldehyde plasticizer （SMF）, the final setting time is reduced to quarter of an hour. Similar changes can also be found in the rate of exothermic hydration and hydration degree. Formulating STP with suitable addition of PC can enhance the strength, while compositing STP and NAP or SMF weakens the strength. Besides, adding STP or STP and SMF, obvious movement （more than 1ev） of binding energy of Ca2p1/2 and Ca2p3/2 is detected. Compared with STP addition, content of the characteristic element （P） of STP is cut down form 1.1% to 0.49% by compositing STP with SMF. Furthermore, as hydration age increases, hydration inhibition in the presence of admixtures weakens and even disappears within 56 h.

Effect of Plasticizers on Properties of Rice Straw Fiber Film

In order to improve the properties of rice straw fiber film, one factor contrast test method was employed. Plasticizer type was chosen as input variable, dry tension strength and elongation, wet tension strength and elongation, bursting strength and tearing strength were chosen as indexes. The results showed that there were significant differences among the means of dry tension strength, dry elongation and bursting strength of different plasticizers; there were not significant differences among the means of wet tension strength, wet elongation and tearing strength of different plasticizers; for dry tension strength and elongation, glycerol had a significant difference with sorbitol and PEG, no significant difference was observed between sorbitol and PEG, dry tension strength added glycerol had been reduced 6.8% compared with that added sorbitol, reduced 9.5% compared with that added PEG; elongation had been improved 6.1% and 9.4%, respectively; for bursting strength, sorbitol had a significant difference with glycerol and PEG, no significant difference was observed between glycerol and PEG; bursting strength added glycerol and added PEG had been improved 6.9% and 5.6%, respectively compared with that of the added sorbitol. The results provided a theoretical reference for further improving the straw fiber film manufacturing process.

FIBRED MAGNESIUM HYDROXIDE AND FLAME-RESISTANT POLYENE MATERIAL

The fibred magnesium hydroxide from the bracite was treated with a surface active agent. The modified fibred magnesium hydroxide as flame-retardant, boric acid, barium stearate, polydimethyl siloxane fluid, vinyltriethoxysilane as synergists of the flame-retardant were added to polyene resin. The flame-resistance polyene material prepared meets the requirements of EWCZ-6287-1. (Author abstract) 2 Refs.

Rheological Behaviors of Fresh Cement Pastes with Polycarboxylate Superplasticizer

The rheologicalbehaviors of fresh cement paste with polycarboxylate superplasticizer were systematically investigated.Influentialfactors including superplasticizer to cement ratio（Sp/C）,water to cement ratio（w/c）,temperature,and time were discussed.Fresh cement pastes with Sp/Cs in the range of 0 to 2.0% and varied W/Cs from 0.25 to 0.5 were prepared and tested at 0,20 and 40 °C,respectively.Flowability and rheologicaltests on cement pastes were conducted to characterize the development of the rheologicalbehavior of fresh cement pastes over time.The exprimentalresults indicate that the initialflowability and flowability retention over shelf time increase with the growth in superplasticizer dosage due to the plasticizing effect and retardation effect of superplasticizer.Higher temperature usually leads to a sharper drop in initialflowability and flowability retention.However,for the cement paste with high Sp/C or w/c,the flowability is slightly affected by temperature.Yield stress and plastic viscosity show similar variation trends to the flowability under the abovementioned influentialfactors at low Sp/C.In the case of high Sp/C,yield stress and plastic viscosity start to decline over shelf time and the decreasing rate descends at elevated temperature.Moreover,two equations to roughly predict yield stress and plastic viscosity of the fresh cement pastes incorporating Sp/C,w/c,temperature and time are developed on the basis of the existing models,in which experimentalconstants can be extracted from a database created by the rheologicaltest results.

A Novel Plasticizer for the Preparation of Thermoplastic Starch

in this paper, ethylenebisformamide was synthesized and used as a novel plasticizer for cornstarch to prepare thermoplastic starch （TPS）. FT-IR expressed that ethylenebisformamide formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch. X-ray diffraction （XRD） showed that the typical A-style crystallinity in the native starch has been destructed. By scanning electron microscope （SEM） native cornstarch granules were proved to transfer to a homogeneous system. After being stored for one week at RH=33%, the mechanical properties of EPTPS was also studied. The elongation reached to 264% utmost. As a novel plasticizer, ethylenebisformamide would be practical to extend TPS application scopes.

Studies on Epoxidised Castor Oil as Co-Plasticizer with Epoxidised Soyabean Oil for PVC Processing

An acidic cation exchange resin has been used to prepare epoxidised castor oil(ECO)which was used as a co-plasticizer with epoxidised soyabean oil(ESBO)for processing polyvinyl chloride(PVC).The structure of ECO was confirmed and its physico chemical properties were evaluated.PVC/(ESBO&ECO)blends were prepared by melt mixing and compression molded into sheets.The specimens were evaluated for tensile properties,impact strength and hardness.While the tensile strength did not vary much,the elongation reduced with the replacement of ESBO with ECO.Dynamic mechanical studies revealed that the glass transition temperature increased with incorporation of ECO,however,the storage modulus was not altered much.Replacing 20%of ESBO with ECO resulted in blends with desired thermal and mechanical properties without affecting the processability of PVC.

Synthesis and Kinetics of Hydrogenated Rosin Dodecyl Ester as an Environmentally Friendly Plasticizer

The plasticizer is an important polymer material additive.Non-toxic and environmentally friendly plasticizers are developed recently in order to decrease fossil fuel reserves,serious environmental pollution and the toxicity of phthalate esters.In this study,a new,efficient and environmentally friendly plasticizer of hydrogenated rosin dodecyl ester was prepared by an esterification reaction of hydrogenated rosin and dodecanol.The influences of different reaction conditions(including different catalysts,the catalyst concentration,the ratio of the reactants,reaction temperature,and reaction time)on the esterification yield are examined and discussed.Hydrogenated rosin dodecyl ester with 71.8%yield was synthesized under the optimized reaction conditions(1:0.8 molar ratio of rosin to dodecanol,1 mol%tetrabutyl titanate concentration,and 210℃for 6 h).The esterification reaction is a second-order reaction,and kinetic calculations showed that the activation energy is 39.77 KJ·mol^(−1).The structure of the hydrogenated rosin dodecyl ester was confirmed by FT-IR spectroscopy and^(13)C NMR spectrum.Besides,the thermal stability of target product(hydrogenated rosin dodecyl ester)was also tested by thermal gravimetric analysis(TGA),which showed a good thermal stability.

Understanding the alkyl effect of geminal dinitropropyl ester energetic plasticizers on hydroxyl terminated polybutadiene(HTPB):Simultaneous tuning on low temperature behavior and processability

Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.

Synthesis of Bio-Plasticizer from Soybean Oil and Its Application in Poly(Vinyl Chloride) Films

Herein,epoxidized soybean oil methyl ester(ESOM)plasticizer was synthesized for the preparation of plasticized poly(vinyl chloride)(PVC)films by the alcoholysis and epoxidation.The chemical structure of ESOM was investigated by infrared spectrum and 1 H nuclear magnetic resonance.The effect of content of ESOM and petroleum based plasticizer di-2-ethylhexyl phthalate(DEHP)on the performance of plasticized PVC films was studied.The result showed that substituting DEHP with ESOM can improve the thermal stability of plasticized PVC films.When the weight ratio of ESOM and PVC is fixed at 1:2,plasticized PVC film presents higher elongation at break(350.8%vs.345.1%)and lower tensile strength(14.21 MPa vs.15.8 MPa)compared with PVC plasticized with DEHP.ESOM showed less weight loss than DEHP in all solvents.The excellent migration resistance of ESOM is helpful to improve stability of plasticized PVC films.In all,the obtained bio-based plasticizer will be potential to replace petroleum based plasticizer DEHP in flexible PVC materials.