Polymer Main Chain Research Articles

Polymer organic cathodes enable efficient desolvation for highly stable sodium-ion batteries

A novel organic polymer cathode namely poly(anthraquinone-alt-benzene) (PAQB, ∼190 mAh g−1) is intentionally designed and synthesized for sodium-ion batteries (SIBs). Full characterizations are carried out to define its polymer nature. Due to the strong π-π interaction of polymer main chains, the insoluble PAQB solid exhibits very efficient desolvation process against the solvated Na+ ions in liquid electrolytes when compared to its insoluble dimer analogue (BAQB), leading to its highly impressive cycle stability and long material life. In half cells, PAQB can realize an average discharge capacity of 128 mAh g−1 during the ultra-long lifespan over 1 year. In the full cells with Na3Bi anode, the resulting PAQB II Na3Bi SIBs can realize the peak discharge capacity of 172 mAh g−1cathode and stably hold 160 mAh g−1cathode after 1000 cycles at 200 mA g−1. To the best of our knowledge, PAQB is among the top cathodes currently reported for SIBs. And this work forwards a significant step for the application of organic electrodes in SIBs.

Synthesis and Gas Separation Properties of Aromatic Polyimides Containing Noncoplanar Rigid Sites

Four aromatic polyimides were prepared using a conventional two-stage polymerization reaction of diamine monomers containing different noncoplanar rigid sites with commercially available dianhydride 6FDA. All polymers displayed high relative molecular masses, excellent solubilities, and outstanding thermal properties with Tg values higher than 260 °C, which ensured that they were able to be casted as dense films for gas permeation measurement. The comprehensive gas transport properties of four prepared polyimides were higher than conventional aromatic polyimides (e.g., Matrimid 5218 and Kapton), which suggested that the incorporation of the noncoplanar rigid groups into the polymer main chain was beneficial to prevent segment packing as well as to enhance the gas separation properties. The pure CO2 permeability coefficient of the spirobichroman-based polyimide (6FDA-BDA) was 2.9 times as high as that of Matrimid 5218, without sacrificing selectivity. Moreover, the effect of different noncoplanar rigid sites on the gas separation performance of aromatic polyimides was systematically investigated. By measurements of FFV, density, and d-spacing, it has been observed that the incorporation of different noncoplanar rigid sites significantly affected the microstructure, thus affecting the gas transport. For example, because the polyimide containing pendent phenyl groups (6FDA-BDM) had the lowest FFV and the densest segment packing, it exhibited the lowest permeability. Hence, the basic insights to the structure/property relationships of the four polyimides obtained in this work offer a meaningful guide for next-generation gas separation membranes.

Colorless Electrochromic/Electrofluorochromic Dual-Functional Triphenylamine-Based Polyimides: Effect of a Tetraphenylethylene-Based π-Bridge on optoelectronic properties

Electrochromic/electrofluorescence (EC/EFC) bifunctional polymer materials with electrochemically switchable colors and fluorescence intensities have attracted significant research attention due to their promising applications in optoelectronic devices. Tetraphenylethylene (TPE) can improve nature-state transmittance and exhibit solid fluorescence and cyclic stability when used as a π-bridge and fluorescence structure in EC/EFC polymer main chains. Herein, 6 novel polyimides with three different TPE-based π-bridge structures were designed and synthesized to investigate the effect of π-bridge units (short, extended, and interrupted conjugation) on optoelectronic properties. The structure–property relationships of the six polyimides were investigated by electrochemistry, electrospectroscopy, and theoretical calculations. Introduction of the TPE structure effectively reduced the polyimide absorption in the ground state, provided different colored states, and induced aggregation-induced emission (AIE) by changing the conjugation type. The structural influences on the electron redox reaction, energy level, absorption/luminescent spectra, and cycle stabilities were systematically investigated. The designed polyimides were colorless (L* > 97) and showed good EC/EFC dual-switching properties: colorless-to-colorful EC switching performance (including a black-colored state), AIE-enhanced EFC performance (including deep-blue fluorescence), 1.7/2.1 s colored/bleached switch, and EC/EFC cyclic stability over 500/300 cycles.

Preparation of a Bioadhesive Poly(Acrylic Acid)/Polyvinylpyrrolidone Complex Gel and Its Clinical Effect on Dental Hemostasis.

Poly(acrylic acid) (PAA) is a water-soluble synthetic polymer that exhibits bioadhesive properties and has been applied in various novel medical devices, such as drug-delivery carriers and hemostatic agents. PAA forms a water-insoluble complex when mixed with polyvinylpyrrolidone (PVP). If PAA and PVP are mixed in water, they form an aggregated precipitate, which neither swells nor adheres to tissues. The formation of the hydrophobic complex was caused by hydrophobic interactions between the main chains of both polymers aligned the same as a zipper. To hinder the zipper-like alignment of the polymer main chains, hyaluronic acid (HA), a macromolecular viscous polysaccharide, was added to the PVP solution prior to complex formation. When the initial concentration of PAA was lower than 0.05%, HA effectively prevented the aggregation of PAA/PVP complexes and resulted in a slightly clouded suspension. Freeze-drying of the mixture yielded a soft white sponge, which could immediately swell in water to form a highly bioadhesive hydrogel. The PAA/PVP complex prepared with HA exhibited high hemostatic efficiency in clinical studies, even in patients on antithrombotic drugs.

Polymers from organosilicon derivatives of 5-norbornene-2-methanol for membrane gas separation

In this work, we have proposed a new strategy to the synthesis of norbornene-type monomers with Si–O–C structural motifs via a straightforward and selective dehydrogenative addition reaction between 5-norbornene-2-methanol and trialkylsilanes. As a result, a set of monomers with various trilalkylsiloxy groups (alkyl – CH3, C2H5, and n-C3H7) was synthesized with the yields of 89–90%. These monomers exhibited a high reactivity in both metathesis and vinyl-addition polymerization, affording high-molecular-weight products in yields up to 90%. The metathesis polymers were rubbery with glass transition temperatures from −29 to +23 °C, while related isomeric vinyl-addition polynorbornenes were glassy polymers. Permeability (P) and diffusion (D) coefficients for these polymers were systematically evaluated for permanent gases (He, H2, O2, N2, and CO2) and C1–C4 alkanes. Studying their gas transport properties allowed to establish new structure-property relationships. Particularly, the length of alkyl fragments in trilalkylsiloxy group affected differently gas permeability of metathesis (rubbery) and vinyl-addition (glassy) polymers. Besides, it was shown that the method of linking the Si–O–C-containing group to the main chains of polymers played very important role: Alk3SiO-substituted polynorbornenes are more permeable than isomeric (AlkO)Alk2Si-substituted ones. For the metathesis polynorbornenes, P(CO2) were in the range of 152–226 Barrer, and ideal selectivity (α) of CO2/N2 – 13-16; for the vinyl-addition polynorbornenes, P(CO2) = 230–500 Barrer, and α(CO2/N2) = 14–17. Among studied polymers, promising results for ethane/methane separation was demonstrated by metathesis polynorbornene bearing tri(n-propyl)siloxymethyl substituents: P(C2H6) = 138 Barrer and α(C2H6/CH4) = 2.4. The obtained polymers were also characterized by using TGA, WAXD, and nitrogen adsorption-desorption methods.

Chiroptical Characteristics of Nanosegregated Phases in Binary Mixture Consisting of Achiral Bent-Core Molecule and Bent-Core Base Main-Chain Polymer.

In this paper, a binary mixture system consisting of an achiral bent-core molecule and a bent-core base main-chain polymer is described. The mixture exhibits an intriguing nanosegregated phase generated by the phase separation of the helical nanofilament B4 phase (originating from the bent-core molecule) and the dark conglomerate phase (originating from the bent-core base main-chain polymer). This nanosegregated phase was identified using polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction analysis. In this nanosegregated phase, the enantiomeric domains grew to a few millimeters and a giant circular dichroism was observed. The structural chirality of the helical nanofilament B4 phase affected the conformation of the bent-core base main-chain polymer embedded within the helical nanofilament networks of bent-core molecules.

Crystalline lamellar films with honeycomb structure from comb-like polymers of poly(2-long-alkyl-2-oxazoline)s

Comb-like copolymers are usually structured by grafting polymeric side chains onto main polymer chain. There are few reports of comb-on-comb polymers in which dense secondary side chains are grafted onto primary side chain. In this work, we synthesized comb polymers with grafted-on-graft side chains (c-PEI-g-Acyl) via an effective acylation reaction of comb polymers possessing polyethyleneimine (PEI) side chain with long-alkyl acyl chlorides. For comparison, we also synthesized homopolymers l-PEI-g-Acyls via reaction of linear PEI with long-alkyl acyl chlorides. Then, we investigated their crystalline feature in the film formation by XRD, DSC and SEM, and found that the polymers tend to form hexagonal lamella structures with bilayer alkyl spacing. The comb polymers c-PEI-g-Acyls and linear polymers l-PEI-g-Acyls were used in preparation of honeycomb film by the “breath-figure” process by dropping chloroform solution of the polymers on substrate. Different to many honeycomb polymeric films which are supported by amorphous phase, interestingly, our polymers easily afford honeycomb films which are supported by crystalline lamellae frames under higher humidity condition. It was found that the comb polymers of c-PEI-g-Acyls with longer PEI primary side chain and long alkyl secondary side chain have advantages in producing honeycomb film than linear polymers of l-PEI-g-Acys.

Synthesis and electrochemical properties of polyimide containing nona-aniline

A main-chain structured electroactive polyimide (EPI) based on nona-aniline was synthesized via oxidative coupling between p-phenylenediamine (p-PDA) and a monodisperse tetra-aniline precursor. The structure and electrochemical properties of the EPI were studied by FTIR, UV–vis and cyclic voltammetry (CV), respectively. The thermal and anticorrosion properties of the EPI were compared with its penta-aniline analogue. The conductivity of the EPI is 6.27 × 10−5 S･cm−1 which is about ten times higher than that of its penta-aniline analogue. T10% of EPI is 509 °C, significantly higher than those of reported main-chain polyaniline or side-chain polyaniline. Moreover, compared with its penta-aniline analogue, the anti-corrosion protecting efficiency of the EPI is increased by 12%. Results show that conjugated length extension of oligoanilines in a main-chain structured electroactive polymer system can significantly facilitate intra-molecular and inter-molecular charge transporting abilities, and consequently increase the functional efficiency of the materials.

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Barbier Hyperbranching Polymerization-Induced Emission from an AB-Type Monomer.

Luminescent polymer materials have gained considerable research efforts in the past decades and are generally molecular designed by extending the π system of the polymer main chain or by incorporating chromophores into the polymer chain, which suffer from poor solubility, difficult synthesis, or multi-step procedures. Meanwhile, according to the step-growth polymerization theory, synthesis of hyperbranched polymers from an AB-type monomer is still challenging. Herein, we report a one-pot synthesis of nonconjugated luminescent hyperbranched polymer material via Barbier hyperbranching polymerization-induced emission (PIE) from an AB-type monomer. The key step in the realization of the hyperbranched polymer is bi-functionalization of a mono-functional group. Through a Barbier reaction between an organohalide and an ester group in one pot, bi-functionalization of mono-functional ester is realized through two-step nucleophilic additions, resulting in hyperbranched polytriphenylmethanols (HPTPM). Attributed to through-space conjugation and inter- and intramolecular charge-transfer effects induced by polymer chain, nonconjugated HPTPMs are PIEgens, which are tunable by monomer structure and polymerization time. When all phenyl groups are rotatable, HPTPM is aggregation-induced emission type PIEgen. Whereas, it is aggregation-caused quenching type PIEgen if some phenyl groups are rotation forbidden. Further potential applications of PIEgen are in the fields of explosive detection and artificial light harvesting systems. This work, therefore, expands the monomer library and molecular design library of hyperbranched polymers through "bi-functionalization of mono-functional group" strategy, which eventually expands the preparation library of nonconjugated luminescent polymer materials through one-pot PIE from nonemissive monomer.

Competition between Circularly Polarized Light and Molecular Chirality in the Assembly of Main-chain Liquid Crystalline Polymers

Abstract Polymeric systems responding to chiral information are actively pursued for applications in optoelectronics and photonics. Here we report on the diastereomeric relationship between chiral liquid crystal polymers and circularly polarized light (CPL). We synthesize a chiral copolymer incorporating photoisomerizable diazobenzene moieties as well as isosorbide-based monomers. The circular dichroism of the film can be inverted by irradiation with CPL indicating that the influence of the chiral subunits on the helicity of the cholesteric arrangement can be overruled by the action of CPL. By following the out-of-equilibrium photo-switching process over time, we demonstrate that the formation of helical ordering in the chiral liquid crystal phases is much faster by CPL irradiation than by heat.

Linear polyurethane ionenes for stable interlayer of organic photovoltaics

Non-conjugated polymer electrolytes (nCPEs) are applied as electron transporting layers (ETLs) in organic photovoltaic (OPV) devices with conventional structures and used as competent interfacial layers. The new nCPEs are prepared from dihydroxyl pyrrolidinium bromide ionic liquid monomers and m-diphenylene diisocyanate to create linear polyurethane ionenes with main-chain ionic salt moieties. The ultraviolet photoelectron spectroscopy (UPS) results reveal that the formation of an interfacial dipole by the nCPEs facilitates electron transfer from the photoactive layer to the electrode. The OPV devices with the new nCPEs show a power conversion efficiency (PCE) comparable to that with the well-known conjugated polymer electrolyte poly(9,9-bis(3’-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene))dibromide (PFN), which possesses charged sites on its pendants, as an ETL. The OPV device with the synthesised nCPE exhibits superior stability compared to the PFN-based OPV devices. Our results suggest that the nCPEs containing ionic salt structures on polymer main chains are more suitable ETLs for OPV devices than PFN-based layers with pendant salt moieties.

Spirobisindane-Containing Imidazolium Polyimide Ionene: Structural Design and Gas Separation Performance of “Ionic PIMs”

Polymers of intrinsic microporosity (PIMs) have been explored extensively for challenging membrane separation applications. Manipulating microporosity and functionalities of PIM structures has played a major role in the design of membrane materials that can lead to cost-effective CO2 separation processes. Here we have developed a new class of ionenes, in which imidazolium cations are attached (via imides) to spirobisindane groups commonly associated with PIMs yielding a novel ionic-mediated polymer of intrinsic microporosity or “PIM-polyimide ionene” for high-performance CO2 separations. The PIM-polyimide ionene was prepared via Menshutkin reactions between a newly designed spirobisindane-containing bisimidazole monomer and α,α′-dichloro-p-xylene. The resulting thermally and mechanically stable transparent membrane was further studied for its potential utility for CO2 separation. The newly developed PIM-polyimide ionene demonstrated excellent CO2 separation performance relative to other light gases including H2, N2, and CH4. For CO2/CH4 separation, the results surpass the 2008 Robeson upper bound with CO2 permeability of 356.2 barrer and permselectivity of 55. Most notably, the PIM-polyimide ionene membrane outperformed all our previously developed imidazolium ionenes due to the superior CO2 permeability imparted by spirobisindane groups while achieving a comparable performance within the general range of other functionalized PIMs reported in the literature. This unprecedented result of PIM-polyimide ionenes arises from the inclusion of both highly contorted “spiro” centers and the imidazolium cations which precisely alternate in the main chain polymer backbones, resulting in both high diffusivity selectivity and solubility selectivity. It is also noteworthy that PIM-polyimide ionenes exhibited high tolerance against physical aging, as all the gases exhibited very stable permeability and permselectivity values even after a period of 12 months. We hypothesize that the resistance to aging is due to the interactions between ionic groups stabilizing the structure of the polymer matrix, and as such, the ionene microstructure is already close to equilibrium when the membrane is formed. Overall, this is the first example for the integration of PIM structures within the ionene configuration, providing access to potentially numerous novel PIM-ionene materials that can be used in the development of CO2 selective membranes for applications in flue gas, natural gas, and syngas separations.

Enantioseparation on helical poly(diphenylacetylene)s bearing optically-active pendants: Effects of differences in higher-order structures of kinetically-trapped and thermodynamically-stable states on chiral recognition ability

An optically-active poly(diphenylacetylene) (PDPA) bearing carboxy pendant groups with left-handed helicity memory (M-h-poly-1), synthesized using the noncovalent helicity-induction-and-memory strategy, was converted into a PDPA bearing optically-active pendant groups through an amide bonding (M-hKT-poly-2S), while maintaining the left-handed helicity memory, by reaction with (S)-1-phenylethylamine ((S)-2) using a condensing reagent at room temperature. Its chiral recognition ability was investigated as a chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC). M-hKT-poly-2S exhibited significantly different chiral recognition ability towards racemates compared to the previously reported corresponding helical PDPA bearing the same optically-active pendant groups (M-hTS-poly-2S) (prepared by the reaction of an optically-inactive PDPA bearing carboxy pendants with (S)-2, followed by thermal annealing, to induce a left-handed helical structure in the polymer main chain). Although the main chains of both M-hKT-poly-2S and M-hTS-poly-2S formed almost completely left-handed helical structures, their higher-order structures varied slightly, as confirmed by various spectroscopic methods (UV-Vis, circular dichroism (CD), IR, and vibrational CD). M-hKT-TS-poly-2S, the PDPA formed on the thermal annealing of M-hKT-poly-2S, exhibited the same higher-order structure and chiral discrimination ability as M-hTS-poly-2S. Therefore, slight differences in the higher-order structures of the kinetically-trapped metastable state (M-hKT-poly-2S) and the thermodynamically-stable state (M-hTS-poly-2S), due to differences in synthetic procedures, significantly impact their chiral recognition abilities as CSPs, even with identical primary structures and helix-sense of the polymer main chain.

New poly(ether-phosphoramide)s sulfides based on green resources as sensitive films for the specific impedimetric detection of nickel ions

For the development of selective and sensitive chemical sensors, we have developed a new family of poly(ether-phosphoramide) polymers. These polymers were obtained with satisfactory yields by nucleophilic aromatic polycondensation using isosorbide as green resources, and bisphenol A with two novel difluoro phosphinothioic amide monomers. Unprecedented, the thiophosphorylated aminoheterocycles monomers, functionalized with two heterocyclic amine, N-methylpiperazine and morpholine were successfully obtained by nucleophilic substitution reaction of P(S)–Cl compound. The resulting polymers were characterized by different analytical techniques (NMR, MALDI–ToF MS, GPC, DSC, and ATG). The resulting partially green polymers, having tertiary phosphine sulfide with P–N side chain functionalities along the main chain of polymers are the sensitive film at the surface of a gold electrode for the impedimetric detection of Cd, Ni, Pb and Hg. The bio-based poly(ether-phosphoramide) functionalized with N-methylpiperazine modified sensor showed better analytical performance than petrochemical based polymers for the detection of Ni2+. A detection limit of 50 pM was obtained which is very low compared to the previously published electrochemical sensors for nickel detection.

Synthesis and properties of a new ether-free poly(bis-alkylpiperidinium) polymer for the anion exchange membrane

Developing anion exchange membranes (AEMs) with high performance and excellent alkaline stability is a huge challenge to the fuel cell. Herein, a new bispiperidinium compound is synthesized through a nucleophilic reaction between 4,4′-trimethylenebis (1-methyl piperidine) and 4-bromomethylbiphenyl. Subsequently, a novel poly(bis-alkylpiperidinium) polymer (i.e. Tmmp-Bmb-TFAc) is synthesized through the Friedel-Crafts polycondensation of bispiperidinium monomer and 1,1,1-trifluoroacetone. The synthesized ether-free Tmmp-Bmb-TFAc contains two piperidinium cations per polymer repeat unit in the main chain, which thus is employed as the AEM. The obtained AEM exhibits high ionic exchange capacity of 2.25 mmol g−1, low volume swelling of 13.6% and moderate tensile strength of 12.3 MPa in Br- form simultaneously. Meanwhile, the Tmmp-Bmb-TFAc membrane achieves a high conductivity of 45.0 mS cm−1 at 80 °C and possesses an excellent alkaline stability in 1 mol L−1 KOH at 60 °C within 480 h. Furthermore, no degradation of the polymer backbone is detected by 1H NMR spectra when immersing the membrane in 1 mol L−1 KOH at 80 °C. This work provides a gentle and facile approach on the design and preparation of ether-free AEMs with cations in the polymer main chain.

Intrinsic healable mechanochromic materials via incorporation of spiropyran mechanophore into polymer main chain

The development of multifunctional self-healing materials is highly demanding. Herein, an intrinsic healable mechanochromic (i-HMC) material was synthesized via the incorporation of spiropyran mechanophore into the polymer main chain. The as-synthesized i-HMC material exhibited mechanically induced color change as well as great self-healing performance. The mechanical properties of the damaged sample can be completely restored with a high healing efficiency of 98.3% and great toughness of 447 MJ/m 3 . The mobility behaviors of the polymer chain and hydrogen bonding interaction were analyzed through rheological measurements and in-situ FT-IR. The as-synthesized intrinsic materials are capable of dynamic, yet tough healable mechanochromic functions. In contrast to the composites, the intrinsic healable mechanochromic materials contain no foreign additives, which are highly potential for future applications in structural health detectors, load-bearing elements, and wearable devices. • The intrinsic materials exhibited tunable mechanochromic and self-healing bifunctions. • High healing efficiency was achieved for the as-synthesized materials with a large toughness of 447 MJ/m 3 . • Rheology measurements and in-situ FT-IR were utilized to study the healing mechanism.

Double organic groups‐containing polyhedral oligomeric silsesquioxane filled epoxy with enhanced fire safety

AbstractTo simultaneously improve the flame retardancy, smoke suppression, mechanical properties, and dielectric properties of epoxy resin (EP), a series of polyhedral oligomeric silsesquioxane containing vinyl and epoxy groups (EV‐POSSs) was designed and successfully synthesized. The results of Fourier transform infrared (FT‐IR), Nuclear Magnetic Resonance (NMR) and mass spectra indicated that the EV‐POSSs possessed two main cage structures, T10 and T12. The epoxy groups attaching to POSS connected the polymer main chains, forming higher crosslinking‐density networks. The self‐polymerization of vinyl groups under high temperatures improved the mechanical property and the quality of char residues. Based on our study, the introduction of EV‐POSSs can enhance the flame retardancy, smoke suppression, mechanical and dielectric properties. Compared with pure EP, the dielectric constant of EP containing 2 wt% EV‐POSS dropped from 3.9 to 3.6 at 106 Hz. In addition, with the 10 wt% EV‐POSSs, the peak of heat release rate and total smoke production also reduced by 50.7% and 36.7%, respectively. Most notably, the maximum smoke density declined by 44.8% due to the EV‐POSSs simultaneously containing epoxy and vinyl groups show comprehensive enhancement and occupy spacious applications.

Poly(terphenyl piperidinium) containing hydrophilic crown ether units in main chains as anion exchange membranes for alkaline fuel cells and water electrolysers

Poly(arylene piperidinium) polymers are recognized as promising anion exchange membrane (AEM) materials for alkaline fuel cell and water electrolysis, due to the aryl-ether free polyaromatic backbones and stable piperidinium cations. Herein, hydrophilic crown ether units have been introduced into poly(terphenyl piperidinium) (PDTP) by readily superacid-catalyzed polycondensation of dibenzo-18-crown-6 (DE), p-terphenyl and N-methyl-4-piperidine followed via quaternization. The obtained PDTP membranes showed much higher hydroxide conductivity than the control poly(terphenyl piperidinium) (PTP) sample without DE units, due to their high water uptake. The highest hydroxide conductivity of 110 mS/cm was reached at 80 °C for PDTP-10 (where 10 denoted the molar content of crown ether units) membrane with an ion exchange capacity (IEC) of 2.57 meq./g. The introduction of DE units alleviated the chemical degradation of PDTP membrane in 1 M NaOH at 80 °C as compared to the PTP membranes. Furthermore, membrane electrode assemblies based on PDTP-10 membrane shown a peak power density of 621 mW/cm2 at 60 °C in AEM fuel cells and a current density of 2000 mA/cm2 at 2.1 V for water electrolysers circulated with 1 M NaOH at 80 °C. The in-situ stability tests in fuel cells and water electrolysers also manifested that the chemical structure of PDTP-10 membrane remained intact during short-term durability tests under galvanostatic mode. The above results manifested that AEMs containing hydrophilic crown ether units in the polymer mainchain showed potential in the application for AEM based electrochemical devices.

Secretome analysis of Trichoderma reesei RUT-C30 and Penicillium oxalicum reveals their synergic potential to deconstruct sugarcane and energy cane biomasses

The conversion of lignocellulosic polymers into monomeric sugars demands a plethora of enzymatic activities generally not produced by a single microorganism and induced by the carbon source. In this vein, this work investigates the synergy between the enzymes secreted by the cellulolytic model fungi Trichoderma reesei RUT-C30 (TR) and Penicillium oxalicum (PO) to deconstruct sugarcane straw (SCS) and energy cane bagasse (ECB). TR and PO secrete a similar profile of cellulose-active enzymes resulting in a comparable conversion of SCS and ECB into glucose. The synergy between the enzymes produced by both fungi to break down the cellulose fraction becomes evident by the improvement of glucose titers from ~35–54% and from ~10–17% in SCS and ECB conditions, respectively, reached with the mixture of the secretomes of both fungi. The effect of a hemicellulase-enriched secretome produced by TR is particularly seen in SCS where the xylose yield reached ~15% compared to 5% by PO, remaining unaltered following the mixture of secretomes. However, the secretion of enzymes active in the decorations of the main chain polymers possibly aid PO to access the hemicellulose fraction of ECB reaching xylose yields similar to TR in this condition.