Effect of bio‐based monomers on the scratch resistance of acrylate photopolymerizable coatings

Photopolymerizable clear coatings based on bio‐sourced acrylates, dedicated to the protection of polycarbonate substrates, were studied. The bio‐sourced compounds were not based on triglycerides but were smaller, industrially available molecules similar to classical petro‐based monomers. Their polymerization kinetics was studied by photo‐DSC and was shown to allow high acrylate conversions even at 25 °C. Closely related coatings enriched in alkyl segments, or in monoacrylates to decrease the crosslinking density, were compared. The material composition affects its nanomorphology deduced from X‐ray diffraction. Although these changes in composition can slightly shift the mechanical relaxation, it remains wide, and the elastic modulus remains high (>10⁸ Pa) for all the tested materials. Microscratch experiments highlighted the efficiency of all the new coatings in terms of protection against scratches. Incorporating a monoacrylate, particularly isobornyl acrylate, can improve the scratch resistance especially in terms of critical load (up to 175% increase compared with a classical petro‐based coating). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 379–388     

Application of a bio‐based polyester plasticizer modified by hydrosilicon‐hydrogenation reaction in soft PVC films

A kind of bio‐based plasticizer, poly (hexanediol maleic) (MH), was synthesized using 1,6‐hexalene and maleic acid as raw materials, and it was modified by hydrosilicon‐hydrogenation reaction to improve its plasticizing efficiency. The chemical structure and plasticizing performance of MH and its modification product (MHA) were characterized by Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H‐NMR), X‐ray photoelectron spectroscopy (XPS), and Dynamic mechanical analysis (DMA). It was found that the hydrosilicon‐hydrogenation modification effectively improved the plasticizing efficiency of MH, reflecting on the decreased T_g and the increased elongation at break of PVC blends. The migration resistance of PVC blends was tested and analyzed by solubility parameters, which revealed that the migration stabilities of PVC blends were promoted after modification. It was verified that the hydrogen bonding interaction between the C?O group of plasticizers and α‐hydrogen of PVC exhibited in FTIR analysis was the main reason for the improvement of plasticizer performance of MH. Moreover, a new hydrogen bonding formed between Si? O? Si of MHA and the α‐hydrogen of PVC derived from XPS also caused the further improvement of plasticity for MHA.     

Internal plasticization of poly(vinyl) chloride using glutamic acid as a branched linker to incorporate four plasticizers per anchor point

Internal plasticization of polyvinyl chloride (PVC) using thermal azide‐alkyne Huisgen dipolar cycloaddition between azidized PVC and electron‐poor acetylenediamides incorporating a branched glutamic acid linker resulted in incorporation of four plasticizing moieties per attachment point on the polymer chain. A systematic study incorporating either alkyl or polyethylene glycol esters provided materials with varying degrees of plasticization, with depressed T_g values ranging from ?1 °C to 62 °C. Three interesting trends were observed. First, T_g values of PVC bearing various internal plasticizers were shown to decrease with increasing chain length of the plasticizing ester. Second, branched internal plasticizers bearing triethylene glycol chains had lower T_g values compared to those with similar length long‐chain alkyl groups. Finally, thermogravimetric analysis of these internally plasticized PVC samples revealed that these branched internal plasticizers bearing alkyl chains are more thermally stable than similarity branched plasticizers bearing triethylene glycol units. These internal tetra‐plasticizers were synthesized and attached to PVC‐azide in three simple synthetic steps. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1821–1835     

Synthesis and properties of bio‐based polyurethanes bearing hydroxy groups derived from alditols

Four kinds of bio‐based polyurethanes bearing hydroxy groups in the pendants were synthesized by the polyaddition of D ‐mannitol‐ and D,L ‐erythritol‐derived diols (1,2:5,6‐di‐O‐isopropylidene‐D ‐mannitol and 1,2‐O‐isopropylidene‐D,L ‐erythritol) with hexamethylene diisocyanate and methyl (S)‐2,6‐diisocyanatohexanoate and the subsequent deprotection of the isopropylidene groups. They were hydrolyzed much more quickly than the corresponding protected polyurethanes at 50 °C and pH 7.0, although their hydrolytic degradation rate was lower than that of polyurethanes with saccharic and glucuronic lactone groups, which had been reported in our previous articles. The introduction of D ‐mannitol units to the polyether‐polyurethanes containing poly(oxytetramethylene) glycol units also enhanced their hydrolyzibility. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Partially bio‐based aromatic polyimides derived from 2,5‐furandicarboxylic acid with high thermal and mechanical properties

Two novel bio‐based diamines are synthesized through introduction of renewable 2,5‐furandicarboxylic acid (2,5‐FDCA), and the corresponding aromatic polyimides (PIs) are then prepared by these diamines with commercially available aromatic dianhydrides via two‐step polycondensation. The partially bio‐based PIs possess high glass transition temperatures (T_gs) in the range from 266 to 364 °C, high thermal stability of 5% weight loss temperatures (T_5%s) over 420 °C in nitrogen and outstanding mechanical properties with tensile strengths of 79–138 MPa, tensile moduli of 2.5–5.4 GPa, and elongations at break of 3.0–12.3%. Some colorless PI films (PI‐1‐b and PI‐1‐c) with the transmittances at 450 nm over 85% are prepared. The overall properties of 2,5‐FDCA‐based PIs are comparable with petroleum‐based PI derived from isophthalic acid, displaying the potential for development of innovative bio‐based materials. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1058–1066     

Effects of plasticizers on novel electromechanical actuations with different poly(vinyl chloride) gels

Four different plasticizers were applied to make different poly(vinyl chloride) (PVC) gels, poly(vinyl chloride)‐bis(2‐ethylhexyl)phthalate (PVC‐DOP), poly(vinyl chloride)‐di‐n‐butylphthalate, poly(vinyl chloride)‐bis(2‐ethylhexyl)adipate, and poly(vinyl chloride)‐tris(2‐ethylhexyl)trimellitate. In our previous work, we reported that PVC‐DOP gel exhibits novel and reversible deformations of creeping and jointlike bending induced by direct current electric fields. In this article, we scrutinize the effects of plasticizers on electromechanical actuations, that is, reversible creeping and bending actuation with four of the different aforementioned gels. We measured the relative creeping distance, creeping area, creeping velocity, current observed, and bending angle as a function of applied electric fields for different PVC gels and found significant differences among them. To explain these variations, we compared the utility of plasticizers on the basis of the properties of different PVC gels, such as plasticizer‐retention ability, bending modulus, elongation at break, and the dielectric constant. The mentioned properties of the PVC gels played vital roles on their electromechanical actuations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2119–2127, 2003     

Controllable synthesis of bio‐based polylactide diols using an organocatalyst in solvent‐free conditions

Controllable synthesis of bio‐based polylactide (PLA) diols was realized by the ring‐opening polymerization (ROP) of lactide (LA) in the presence of 1,4‐butanediol (BDO) using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as an organocatalyst in solvent‐free conditions. The catalytic activity and conversion of LA could reach ∼1 kg g⁻¹ DBU and >97%, respectively, and the polymerization yielded polymers with narrow polydispersity index (PDI) (1.15–1.29). Interestingly, the number average molecular weight (M_n) of the obtained PLA diol was in excellent linear relation with the molar ratio of LA and BDO, and hence can be precisely controlled. The structure of the diol was clearly confirmed by ¹H and ¹³C NMR, FTIR, and MALDI‐TOF mass spectra, proving BDO as an initiation‐transfer agent to participate in the polymerization. Kinetic study of the ROP demonstrates a pseudo‐first‐order kinetic model and a controlled “living” nature. Notably, it is found that the glass transition temperature (T_g) of the diol significantly depends on the M_n. Furthermore, various chain transfer agents and organocatalysts can also be used to successfully synthesize well‐defined PLA diols. Especially, functional bio‐based dihydric alcohols such as 2,5‐furandimethanol (FDMO)‐initiated ROP in this system could result in fully bio‐based PLA diols with functionality. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 968–976     

Bio‐based copolymers obtained through miniemulsion copolymerization of methyl esters of acrylated fatty acids and styrene

Polymers based on renewable sources are promising materials, and can find many uses in coatings and adhesive applications. The goal of this work was to synthesize and characterize bio‐based styrene/acrylated fatty acid methyl ester (AFAME) copolymer—poly(styrene‐co‐AFAME) prepared by miniemulsion polymerization. The main strategy adopted was to functionalize the bio‐monomer with acrylic acid that was confirmed by ¹H NMR and FTIR measurements, to allow its free‐radical homo‐ or copolymerization with styrene. Poly(styrene‐co‐AFAME) with different AFAME content were obtained and their composition were evaluated by ¹H NMR. Dynamic light scattering measurements throughout the reactions have indicated a very stable colloidal systems and average particles size ranges 100–150 nm. The structural and physical properties of poly(styrene‐co‐AFAME) were investigated by DTG‐DTA, DSC which displayed a decreasing of glass transition temperature with increase of AFAME content. The results showed in this study have indicated that the poly(styrene‐co‐AFAME) can be used in several fields because their characteristics are totally distinct. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1422–1432     

Synthesis of bio‐based poly(ethylene 2,5‐furandicarboxylate) copolyesters: Higher glass transition temperature,better transparency,and good barrier properties

The bio‐based polyester, poly(ethylene 2,5‐furandicarboxylate) (PEF), was modified by 2,2,4,4‐tetramethyl‐1,3‐cyclobutanediol (CBDO) via copolymerization and a series of copolyesters poly(ethylene‐co‐2,2,4,4‐tetramethyl‐1,3‐cyclobutanediol 2,5‐furandicarboxylate)s (PETFs) were prepared. After their chemical structures and sequence distribution were confirmed by nuclear magnetic resonance (¹H‐NMR and ¹³C‐NMR), their thermal, mechanical, and gas barrier properties were investigated in detail. Results showed that when the content of CBDO unit in the copolyesters was increased up to 10 mol%, the completely amorphous copolyesters with good transparency could be obtained. In addition, with the increasing content of CBDO units in the copolyesters, the glass transition temperature was increased from 88.9 °C for PET to 94.3 °C for PETF‐23 and the tensile modulus was increased from 3000 MPa for PEF to 3500 MPa for PETF‐23. The barrier properties study demonstrated that although the introduction of CBDO units would increase the O₂ and CO₂ permeability of PEF slightly, PECF‐10 still showed better or similar barrier properties compared with those of PEN and PEI. In one word, the modified PEF copolyesters exhibited better mechanical properties, higher glass transition temperature, good barrier properties, and better clarity. They have great potential to be the bio‐based alternative to the popular petroleum‐based poly(ethylene terephthalate) (PET) when used as the beverage packaging materials. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3298–3307     

L‐arabinitol‐based functional polyurethanes

Three new polymerizable diols, based on mono‐, di‐, and tri‐O‐allyl‐L ‐arabinitol derivatives, were prepared from L ‐arabinitol as versatile materials for the preparation of tailor‐made polyurethanes with varied degrees of functionalization. Their allyl functional groups can take part in thiol‐ene reactions, to obtain greatly diverse materials. This “click” reaction with 2‐mercaptoethanol was firstly studied on the highly hindered sugar precursor 2,3,4‐tri‐O‐allyl‐1,5‐di‐O‐trityl‐L ‐arabinitol, to apply it later to macromolecules. A polyurethane with multiple pendant allyl groups was synthesized by polyaddition reaction of 2,3,4‐tri‐O‐allyl‐L ‐arabinitol with 1,6‐hexamethylene diisocyanate, and then functionalized by thiol‐ene reaction. The coupling reaction took place in every allyl group, as confirmed by standard techniques. The thermal stability of the novel polyurethanes was investigated by thermogravimetric analysis and differential scanning calorimetry (DSC). This strategy provides a simple and versatile platform for the design of new materials whose functionality can be easily modified. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Ionic Liquid‐Based,Liquid‐Junction‐Free Reference Electrode

In this paper, we describe a new type of polymer membrane‐based reference electrode (RE) based on ionic liquids (ILs), in both liquid‐contact (LCRE) and solid‐contact reference electrode (SCRE) forms. The ILs used were bis(trifluoromethane sulfonyl)amid with 1‐alkyl‐3‐methyl‐imidazolium as well as phosphonium and ammonium cations. In addition to their charge stabilisation role, it was found that the ILs also functioned as effective plasticizers in the PVC matrix. The LCREs and SCREs were prepared using the same design as their corresponding indicator electrodes. LCREs were prepared by casting in glass rings while SCREs were prepared on platforms made using screen‐printing technology, with poly(3‐octylthiophene‐2,5 diyl) (POT) as the intermediate polymer. After potentiometric characterization of the response mechanism, the practical performance of the REs was studied using potentiometric titrations (Pb²⁺ and pH), and characterised using cyclic voltammetry and impedance spectroscopy. All results were compared via parallel experiments in which the novel RE was substituted by a conventional double junction Ag/AgCl reference electrode. The mechanism of response is most likely based on a limited degree of partitioning of IL ions into the sample thereby defining aquo‐membrane interfacial potential. Despite their simple nature and construction, the REs showed excellent signal stability, and performed well in the analytical experiments. The identical mode of fabrication to that of the equivalent indicator (or Ion‐Selective Electrode, ISE) will facilitate mass‐production of both indicator and reference electrode using the same fabrication line, the only difference being the final capping membrane composition.     

Development of completely bio‐based epoxy networks derived from epoxidized linseed and castor oil cured with citric acid

Bio‐based epoxy resins were synthesized from nonedible resources like linseed oil and castor oil. Both the oils were epoxidized through in situ method and characterized via Fourier transform infrared and ¹H‐NMR. These epoxidized oils were crosslinked with citric acid without using any catalyst and their properties compared with diglycidyl ether of bisphenol A‐epoxy. The tensile strength and modulus of epoxidized linseed oil (ELO) were found to be more than those of epoxidized castor oil (ECO)‐based network. However, elongation at break of ECO was significantly higher than that of both ELO and epoxy, which reveals its improved flexibility and toughened nature. Thermogravimetric analysis revealed that the thermal degradation of ELO‐based network is similar to that of petro‐based epoxy. Dynamic mechanical analysis revealed moderate storage modulus and broader loss tangent curve of bio‐based epoxies confirming superior damping properties. Bioepoxies exhibit nearly similar contact angle as epoxy and display good chemical resistant. The preparation method does not involve the use of any toxic catalyst and more hazardous solvents, thus being eco‐friendly.     

Synthesis and characterization of polyurethane ionomers with trimellitic anhydride and dimethylol propionic acid for waterborne self‐emulsifying dispersions

A new synthesis for polyurethane dispersions was developed using both trimellitic anhydride alone and in combination with dimethylol propionic acid as internal emulsifiers. During synthesis of the polyurethane ionomer, Fourier transform infrared spectroscopy was used for monitoring and characterizing both the polyaddition step and the anhydride ring opening process. Depending on the synthesis route, the carboxylic groups are either located at the end of the polymer backbone or additionally statistically distributed within the polymer chain itself. The effect of the carboxylic group's position on the chemical and physical properties, with particular reference to particle size and pH, was analyzed. Three different polyols were used to synthesize the polyurethane dispersions. Driven by the current trend to find renewable alternatives to petrochemical‐based raw materials, one bio‐based polyol was included for the synthesis. The effect of the different structures of the polyurethane dispersions (petrochemical‐ or bio‐based polyols) on mechanical properties and thermal behavior was investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 680–690     

Bio‐based comb‐like copolymers derived from alkyl 10‐undecenoates and maleic anhydride

In this article, 10‐undecenoic acid, based on castor oil, was used a raw material for the synthesis of alternating copolymers. ω‐Unsaturated fatty esters as alkyl 10‐undecenoates were prepared by the esterification reaction of 10‐undecenoic acid with alkyl alcohol. A series of comb‐like copolymers were synthesized by free radical polymerization from maleic anhydride and alkyl 10‐undecenoates copolymers with different length of alkyl side chains in a toluene solution. These copolymers were investigated by ¹H and ¹³C nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry (DSC). The copolymers were obtained in a low molecular weight in a range 3370–12,240 g mol⁻¹ and their structural characterization indicated the formation of alternating copolymers. DSC characterization revealed that these comb‐like copolymers showed amorphous to semicrystalline behavior by increasing the length of side chains. The bio‐based comb‐like copolymers allow for the development of new polymeric materials for several applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1039–1045     

Thermoplastic elastomers based on poly(l‐Lysine)‐Poly(ε‐Caprolactone) multi‐block copolymers

Novel thermoplastic elastomers based on multi‐block copolymers of poly(l ‐lysine) (PLL), poly(N‐ε‐carbobenzyloxyl‐l ‐lysine) (PZLL), poly(ε‐caprolactone) (PCL), and poly(ethylene glycol) (PEG) were synthesized by combination of ring‐opening polymerization (ROP) and chain extension via l ‐lysine diisocyanate (LDI). SEC and ¹H NMR were used to characterize the multi‐block copolymers, with number‐average molecular weights between 38,900 and 73,400 g/mol. Multi‐block copolymers were proved to be good thermoplastic elastomers with Young's modulus between 5 and 60 MPa and tensile strain up to 1300%. The PLL‐containing multi‐block copolymers were electrospun into non‐woven mats that exhibited high surface hydrophilicity and wettability. The polypeptide–polyester materials were biocompatible, bio‐based and environment‐friendly for promising wide applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3012–3018     

Small‐angle x‐ray scattering study of thermoreversible poly(vinyl chloride) gels

Poly(vinyl chloride) (PVC)/bis(2‐ethylhexyl)phthalate (DOP) gels were prepared at room temperature from tetrahydrofuran solutions of PVC and DOP. PVC/DOP gels of different molecular weights at various PVC concentrations (c) were investigated with small‐angle X‐ray scattering (SAXS). The mean distance between two neighboring inhomogeneities (D) and two characteristic lengths, the intrainhomogeneity distance (d₁) and interinhomogeneity distance (d₂), were evaluated from Bragg's law and the distance distribution function, respectively. Both D and d₂ can be expressed by a power‐law relation (e.g., D and d₂ ∝ c^?0.5). After a period of rapid cooling to 25 °C from the sol state, the structural evolution was examined with time‐resolved SAXS measurements. An Avrami analysis with the SAXS invariant data revealed that the growth kinetics of PVC/DOP gels was one‐dimensional growth from predetermined nuclei, regardless of c. These results suggest that the PVC/DOP gels are constructed from a fibrillar structure that forms gel structures at high concentrations or low temperatures. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2340–2350, 2001     

Vanillin‐derived phosphorus‐containing compounds and ammonium polyphosphate as green fire‐resistant systems for epoxy resins with balanced properties

Flame retardants from vanillin when utilized together with ammonium polyphosphate (APP) yield excellent synergistic flame retardancy toward epoxy resins. Bisphenol A epoxy resins have been widely used due to their excellent mechanical properties, chemical resistance, electrical properties, adhesion, etc., while they are flammable. Environment‐friendly and bio‐based flame retardants have captured increasing attention due to their ecological necessity. In this paper, 3 bio‐based flame retardants were synthesized from abundant and more importantly renewable vanillin, and their chemical structures were determined by ¹H NMR and ¹³C NMR. They were used together with APP (an environment‐friendly commercial flame retardant) to improve the fire resistance of bisphenol A epoxy resin. With the addition APP content of 15 phr, the modified bisphenol A epoxy resin could reach UL‐94V0 rating during vertical burning test and limit oxygen index values of above 35%, but reducing APP content to 10 phr, the flame retardancy became very poor. With the total addition content of 10 phr, the epoxy resins modified by 7 to 9 phr APP and 1 to 3 phr bio‐based flame retardants with epoxy groups or more benzene rings showed excellent flame retardancy with UL‐94V0 rating and limit oxygen index values of around 29%. The T_gs of the epoxy resins could be remained or even increased after introducing bio‐based flame retardants, as the control; those of APP alone‐modified epoxy resins compromised a lot. The green synergistic flame‐retardant systems have a great potential to be used in high‐performance materials.     

Pyrazole‐1‐carbothioamide as a Potent Precursor for Synthesis of Some New N‐heterocycles of Potential Biological Activity

Herein, we reported the efficient synthesis of new azoles as bio‐functional analogs, employing the easily obtainable N‐acetyl‐3,5‐diphenyl‐4,5‐dihydro‐1H‐pyrazole‐1‐carbothioamide ( 1 ), as a versatile precursor. The structures of the newly synthesized compounds were elucidated based on their IR, ¹H NMR, and ¹³C NMR mass spectral and elemental analysis. Furthermore, some selected compounds were evaluated in vitro for their antimicrobial activities. The preliminary bioassay results indicate that the majority of the tested compounds exhibited significant antimicrobial activity. Compounds 12 , 11 , 18 , 30 , 22 , 3 , and 2 were found to be the most potent against the tested microorganisms with minimum inhibitory concentration ≤ (12.25 μg/mL), indicating that conjugates bearing thiazole moiety, as well as those with N‐substituted electron‐withdrawing groups, exhibited higher potency than the rest of other compounds.     

Microwave‐assisted solvent‐free synthesis of novel benzoxazines: A faster and environmentally friendly route to the development of bio‐based thermosetting resins

Microwave‐assisted organic synthesis (MAOS) is a well‐established technique that has been used in the enhancement of chemical reactions. Here, the versatility of MAOS is explored describing an environmentally friendly one‐pot route to novel bio‐based benzoxazines under solvent‐free conditions. The lignin derivative, guaiacol, along with paraformaldehyde and different conjugated and nonconjugated amines are successfully fused into guaiacol‐derived 3,4‐dihydro‐2H‐1,3‐benzoxazines. The reactions conducted under microwave irradiation are completed much faster than those under traditional heating, reducing the reaction time from hours to only 6 min, with good yields. The chemical structures of novel benzoxazines are confirmed by ¹H and ¹³C NMR spectroscopy, FTIR, and HR‐MS. The thermal behavior of the resins are evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), showing that these polymers have good thermal stability and wide processing‐window, with onset temperature of polymerization above 230 °C. These results indicate dramatic improvement over the traditional methodologies for the production of this class of resins, which are usually obtained by time‐consuming procedures and in the presence of toxic solvents. Therefore, MAOS can be considered a green and efficient strategy for the synthesis of eco‐friendly benzoxazines. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3534–3544     

Lysine‐based functional blocked isocyanates for the preparation of polyurethanes provided with pendant side groups

This article describes a methodology to prepare polyurethanes (PUs), decorated with pendant (bio)functional side groups, by polymerizing (bio)functionalized blocked diisocyanates with polyols. Caprolactam blocked lysine diisocyanate methyl ester (BLDI‐OMe) was prepared in high yields, by reacting the methyl ester of lysine with carbonyl biscaprolactam. In the absence of a catalyst, the polymerization of BLDI‐OMe with polycaprolactone and polytetrahydrofuran resulted in strictly linear PUs due to the high selective reactivity of the blocked isocyanates (BIs). Although the ester appeared to be less reactive, we found hydrolyzing conditions for the ester, without affecting the BIs. The free acid groups were converted into a N‐hydroxysuccinimide (NHS) activated ester, which was a versatile intermediate for further functionalization. After having demonstrated that model amines were able to substitute NHS without effecting the BIs groups, the same chemistry was used to couple biotin, giving a biotin functional caprolactam blocked lysine diisocyanate. The polymerization with polyols afforded the corresponding biotin‐functional PUs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2036–2049