Louis Pitet

Eindhoven University of Technology | TUE · Department of Chemical Engineering and Chemistry

Conventional synthetic hydrogels often lack the load-bearing capacity and mechanical properties of native biopolymers found in tissue, such as cartilage. In natural tissues, like cartilage, toughness is often imparted via the combination of fibrous non-covalent self-assembly with key covalent bond formation. The controlled combination of supramolec...

Producing block polymers in continuous flow offers significant advantages in terms of versatility, efficiency and scalability.

Thermoplastic copolyesters (TPCs) are important structural components in countless high performance applications that require excellent thermal stability and outstanding mechanical integrity. Segmented multiblock architectures are often employed for the most demanding applications, in which semicrystalline segments of poly(butylene terephthalate) (...

Recycling of plastics presents many challenges, both logistically and conceptually, as a result of the widely varying chemical structures routinely encountered. Among them, thermosets were designed historically in specific to improve strength and durability, and resist degradation, making them non‐processable and unrecyclable. Approaches have emerg...

As minimizing the ecological effects of plastics is of ever greater importance, the replacement of certain conventional fossil‐based plastics with biobased and degradable polymers has become an important strategy. Ring‐opening polymerization (ROP) is a well‐established, industrial polymerization technique especially suited for the production of ali...

Hydrogels are promising candidates for recapitulation of the native extracellular matrix (ECM), yet recreating molecular and spatiotemporal complexity within a single network remains a challenge. Double network (DN) hydrogels are a promising step towards recapitulating the multicomponent ECM and have enhanced mechanical properties. Here, we investi...

Segmented thermoplastic copolyether esters (TPEE's) with a partially renewable hard block containing isosorbide (ISB) and poly(ethylene glycol) (PEG) soft blocks were prepared by melt polycondensation. A range of compositions was accessible despite the relatively low reactivity of the sterically and electronically hindered ISB monomer. The small-sc...

The number of reports using continuous flow technology in tubular reactors to perform precision polymerizations has grown enormously in recent years. Flow polymerizations allow highly efficient preparation of polymers exhibiting well-defined molecular characteristics, and has been applied to a slew of monomers and various polymerization mechanisms,...

The effect of macromolecular architecture on the morphology and thermal characteristics of triblock copolymers was evaluated for linear, H-shaped, and arachnearm architectures with poly(cis-cyclooctene) (PCOE) midblocks flanked with arms of poly(D,L-lactide) (PLA). Chain topology was found to significantly influence the interfacial curvature of the...

A library of Y-shaped poly(dimethylsiloxane) (PDMS)-b-poly(d,l-lactide) (PLA) diblock copolymers and their corresponding linear counterparts were synthesized, and their morphologies and feature sizes in bulk and thin films were compared using small-angle X-ray scattering (SAXS), scanning force microscopy (SFM), and grazing incidence small-angle X-r...

Various complex self-assembled morphologies of lamellar- and cylinder-forming block copolymers comprising poly(dimethylsiloxane)-b-polylactide (PDMS-b-PLA) confined in cylindrical channels were generated. Combining top-down lithography with bottom-up block copolymer self-assembly grants access to morphologies that are otherwise inaccessible with th...

Hydrogels were prepared with physical cross-links comprising 2-ureido-4[1H]-pyrimidinone (UPy) hydrogen-bonding units within the backbone of segmented amphiphilic macromolecules having hydrophilic poly(ethylene glycol) (PEG). The bulk materials adopt nanoscopic physical cross-links composed of UPy-UPy dimers embedded in segregated hydrophobic domai...

We demonstrated that the ring-opening metathesis polymerization (ROMP) of 3-substituted cyclooctenes bearing polar substituents allows the synthesis of highly regio- and stereo-regular polymers. A series of polyalkenamers with 90–99 % head-to-tail/trans configuration were synthetized in good yields (33–87 % yield). Upon saturation of the backbone u...

Hierarchical self-assembly has been demonstrated with diblock copolymers comprising poly(dimethylsiloxane) (PDMS) and poly(lactide) (PLA) with supramolecular, 4-fold hydrogen-bonding junctions. PDMS with a single ureidoguanosine unit at the end was synthesized by a postpolymerization strategy. PLA with a single 1,7-diamidonaphthyridine was synthesi...

Thin films with well-organized arrays of densely packed nanodomains were fabricated from poly(dimethylsiloxane)-b-poly(dl-lactide) (DL) diblock copolymers. As a consequence of the unusually large Flory–Huggins interaction parameter between these repeat units, domains with sizes 10 nm are routinely generated using low molar mass diblock copolymers....

Core–shell polymeric particles consisting of biodegradable polylactide (PLA) arms emanating from a crosslinked polyurethane (PU) core were prepared in situ by a polymerization induced phase separation strategy. Sub-micron sized particles were spawned in dilute solution during polyurethane formation with simultaneous incorporation of end-functional...

AB diblock copolymers were prepared by sequential ring-opening metathesis polymerization of cyclooctenes catalyzed by a Ru-based Grubbs catalyst. The relatively slow polymerization of cis-3-phenylcyclooct-1-ene (3PC) or cis-cyclooct-2-en-1-yl acetate (3AC) was first carried out and then followed by the faster polymerization of unsubstituted cis-cyc...

Multiply functional hydroxyl telechelic poly(cyclooctene-s-5-norbornene-2-methylene methacrylate) was synthesized by ring opening metathesis (co)polymerization of cis-cyclooctene and 5-norbornene-2-methylene methacrylate using the second generation Grubbs catalyst in combination with a symmetric chain transfer agent bearing hydroxyl functionality....

The facile preparation of amphiphilic network coatings having a hydrophobic dimethacryloxy-functionalized perfluoropolyether (PFPE-DMA; M(w) = 1500 g mol(-1)) crosslinked with hydrophilic monomethacryloxy functionalized poly(ethylene glycol) macromonomers (PEG-MA; M(w) = 300, 475, 1100 g mol(-1)), intended as non-toxic high-performance marine coati...

The use of unprotected maleic acid (MA) as a chain transfer agent (CTA) during ring-opening metathesis polymerization (ROMP) of cis-cyclooctene (COE) to provide carboxy-telechelic PCOE with an average degree of polymerization (N) was described. Four samples were initially prepared by polymerizing COE in tetrahydrofuran at 40°C with varying concentr...

3-Substituted cis-cyclooctenes (3RCOEs, R = methyl, ethyl, hexyl, and phenyl) were synthesized and polymerized, and the polymers therefrom were hydrogenated to prepare model linear low density polyethylene (LLDPE) samples. The ring-opening metathesis polymerization (ROMP) of the 3RCOEs using Grubbs' catalyst proceeded in a regio- and stereoselectiv...

The structural and molecular versatility afforded to polymeric materials by ruthenium catalysts during ring-opening metathesis polymerization (ROMP) cannot be exaggerated. This dissertation describes the synthesis of functionalized polyolefins via ROMP with particular emphasis on designing straightforward approaches to materials in which the molecu...

A new strategy has been developed to achieve durable, low surface tension fluorinated polymeric materials by copolymerizing a tetramethacryloxy-modified perfluoropolyether (PFPE) macromonomer and a fluorinated difunctional cross-linker, 1H,1H,6H,6H-perfluoro-1,6-hexyl diacrylate (PFHDA), into very highly cross-linked materials that possess a very h...

We have demonstrated the two-stage preparation of block polymers with various architectures containing mechanistically incompatible monomers. Three new monounsaturated chain transfer agents (CTAs) were synthesized containing two, four, or eight hydroxyl groups and used for the preparation of telechelic poly(cis-cyclooctene) (PCOE) by ring-opening m...

A simplified synthetic approach for the facile synthesis of polylactide graft copolymers utilizing both ring-opening metathesis polymerization (ROMP) and ring-opening transesterification polymerization (ROTEP) was reported. A comparison of the 1H NMR signals from the poly(DL-lactide) (PLA) initiation sites along the poly(1,5-cyclooctadiene-co-5-nor...

Porous polyolefin membranes play an integral role in lithium-ion battery technology as the barrier preventing direct anode and cathode contact. Block polymers containing a sacrificial component have proven to be attractive precursors for nanoporous polymer membranes stemming from their unique ability to self-assemble into mesoscopically organized s...

A series of polylactide-polymenthide-polylactide triblock copolymers containing either amorphous poly(D,L-lactide) or semicrystalline, enantiopure poly(L-lactide) or poly(D-lactide) end segments were synthesized. Small-angle X-ray scattering and differential scanning calorimetry data were consistent with microphase separation of these materials. Th...

ABA triblock copolymers were synthesized by combining ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) with ring-opening polymerization of d,l-lactide. Hydroxyl-functionalized telechelic polyCOD was prepared by taking advantage of chain transfer during ROMP of COD using the acyclic chain transfer agent cis-1,4-diacetoxy-2-b...

Samples of polylactide (PLA) were synthesized by initiating lactide ring opening with glycidol using Sn(Oct)2 catalyst. Under low-temperature solution polymerization conditions, epoxide ring opening is precluded, leading to predominately linear epoxide capped PLA. With high-temperature bulk polymerization, simultaneous lactide and epoxide ring open...