The chemical microstructure of poly(butylene terephthalate) (PBT) copolymers obtained by incorporation of a rigid diol, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane (Dianol 220), into PBT using solid-state polymerization (SSP) and melt polymerization (MP) was analyzed. 13C NMR sequence distribution analysis showed that Dianol was randomly incorporated in the PBT−Dianol copolymers obtained by MP. However, the used 13C NMR sequence distribution analysis method was based on solution NMR. As a ...

The autocatalytic equation derived in this study describes and even predicts the evolution of the number average molecular weight of aliphatic polyesters upon hydrolytic degradation. The main reaction in the degradation of aliphatic polyesters is autocatalytic hydrolysis of ester bonds, which causes the molecular weight to decrease. During hydrolysis of the ester bonds in the main chain of the polyester, the chains are cleaved and the end group concentrations will rise. The fundamentals ...

Co- and terpolyesters based on succinic acid and isosorbide in combination with other renewable monomers such as 2,3-butanediol, 1,3-propanediol, and citric acid were synthesized and characterized. Linear polyesters were obtained via melt polycondensation of nonactivated dicarboxylic acids with OH functional monomers. Polymer end functionality (i.e., hydroxyl or carboxylic acid) was controlled by adjusting the monomer stoichiometry. The glass transition temperatures of the resulting ...

Block copolymers consisting of a polyethylene block and a polar polymer block are interesting structures for the compatibilization of polyethylene/polar polymer blends or polyethylene-based composites. Since the synthesis of polyethylene-based block copolymers is an elaborate process, diblock copolymers consisting of “polyethylene-like” poly­(pentadecalactone) (PPDL) and poly­(l-lactide) (PLLA) were synthesized using a one-pot, sequential-feed ring-opening polymerization of ...

Copolymerization of cyclohexene oxide (CHO) with alicyclic anhydrides applying chromium tetraphenylprophyrinato (TPPCrCl, 1) and salophen (SalophenCrCl, 2) catalysts resulted in polyesters or poly(ester-co-ether)s, depending on the nature of the catalyst, presence of a cocatalyst, solvent and type of anhydride. The combination of 1 as catalyst and 4-N,N-dimethylamino-pyridine (DMAP) as cocatalyst in the copolymerization of CHO with succinic anhydride (SA), cyclopropane-1,2-dicarboxylic ...

The kinetics of the incorporation of an aromatic diol in poly(butylene terephthalate) (PBT) via solid-state polymerization (SSP) was studied. The selected diol was 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane (Dianol 220). Mixtures consisting of 85 mol % PBT and 15 mol % Dianol were isothermally polymerized in the solid-state at 180 °C while the polymerization time was varied. Combining HPLC and 1H NMR spectroscopy results showed that Dianol monomer reacts with PBT via two consecutive ...

Reversible addition fragmentation chain transfer (RAFT)-mediated polymerization was successfully applied for the synthesis of poly(4-vinylpyridine) (P4VP) polymers of predetermined molar mass and of low polydispersity index. These RAFT end-functionalized polymers were then used as macro-RAFT agents and further chain extended with an azeotropic mixture of styrene (STY) and acrylonitrile (AN) (63 mol % STY). Initially, these chain extension experiments were carried out in solution. In that ...

A versatile platform to obtain highly functional macroporous materials was developed. A polymerizable initiator for atom transfer radical polymerization (ATRP) has been incorporated into a high internal phase emulsion (HIPE) without compromising the emulsion stability. Photopolymerization of this formulation led to polyHIPE with ATRP initiator groups on the surface available for polymer grafting reactions. The latter was first demonstrated by grafting of methylmethacrylate (MMA). ...

The electrical conductivity of different carbon materials (multi-walled carbon nanotubes, graphene, carbon black and graphite), widely used as fillers in polymeric matrices, was studied using compacts produced by a paper preparation process and by powder compression. Powder pressing assays show that the bulk conductivity depends not only on the intrinsic material properties but is also strongly affected by the number of particle contacts and the packing density. Conductivities at high ...

Ring-opening copolymerization of cyclohexene oxide with alicyclic anhydrides containing different ring strain (succinic anhydride, cyclopropane-1,2-dicarboxylic acid anhydride, and phthalic anhydride) was performed applying metal salen chloride complexes, (salen)MCl (M = Al, Cr, Co; salen = N,N-bis(3,5-di-tert-butylsalicylidene)diimine) with different metals and ligand–diimine backbones. While some of the bulk copolymerizations afforded poly(ester-co-ether)s, all solution polymerizations ...

The polymerization of N-carboxyanhydride (NCA) at low temperatures is controlled and allows the synthesis of a variety of well-defined polypetides.

We have investigated the polymerization of various amino acid N-carboxyanhydrides (NCAs) at 0 °C. Detailed MALDI-ToF analysis of homopolymerizations of three amino acid NCAs clearly confirms that frequently occurring end-group termination and other side-reactions are absent at 0 °C. The polymerization is thus controlled and homo and ...

Ring-opening copolymerisation of styrene oxide with alicyclic anhydrides containing different ring strains (succinic anhydride, maleic anhydride, citraconic anhydride, cyclopropane-1,2-dicarboxylic acid anhydride, cyclopentane-1,2-dicarboxylic acid anhydride and phthalic anhydride) was performed applying metal salen and tetraphenyl porphyrin complexes where for (salen)MX, M = Cr, X = Cl (1), M = Al, X = Cl (2), M = Mn, X = Cl (3), M = Co, X = OAc (4) and salen = ...

2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the enzymatic ring-opening polymerization (ROP) of omega-pentadecalactone (PDL) and epsilon-caprolactone (CL). The lipase B from Candida antarctica was found to catalyze the cleavage of the ester bond in the HEMA end group of the formed polyesters, resulting in two major transesterification processes, methacrylate transfer and polyester transfer. This resulted in a number of different polyester methacrylate structures, such as ...

The objective of this study was to develop a mathematical model that describes and even predicts the hydrolytic degradation of aliphatic polyesters. From literature, it is known that the main process of degradation of aliphatic polyesters is the autocatalytic hydrolysis of ester bonds. Because of this hydrolysis, polymer chains are cleaved and the molecular weight will decrease. With time, the molecules become small enough for the system to start losing weight, since the small molecules ...

Single-walled carbon nanotubes (SWCNTs) are introduced into a polymer matrix via a latex-based route resulting in a conductive composite. The percolation threshold for a polystyrene (PS)-based composite prepared with SWCNTs dispersed in water using a conventional surfactant like sodium dodecyl sulfate (SDS) is approximately 0.4 wt%. In this study, SDS is substituted by a conductive polymer latex, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) also known as PEDOT:PSS. This latex ...