Thermosetting Resins Based on a Self-Crosslinkable Monomer/Polymer Possessing Meldrum's Acid Groups (original) (raw)
Related papers
Polymer International
The preparation and characterization of a series of chemically functionalized oligosulphones (of approximate Mn 5000–17 000 g mol−1) bearing propenyl groups substituted into the main aromatic backbone is reported. The thermal characterization of the oligomers using differential scanning calorimetry was carried out and the main features of the thermally-initiated process are presented. Blends of the oligomers were formed with a commercial bismaleimide and their thermal characteristics are also discussed.© 2001 Society of Chemical Industry
Journal of Applied Polymer Science, 2002
Two maleimido end-capped poly(ethylene glycol) (m-PEG) of different molecular weights were synthesized and blended at various proportions with bismaleimide resin (4,4Ј-bismaleimido diphenylmethane) (BDM). The curing behavior and the thermal properties of the m-PEG/BDM blends were studied and presented here. It was found that the addition of m-PEG enhanced the processability of the BDM resin significantly. The processing window of the BDM resin was increased from approximately 20 to 80°C. The addition of m-PEG modified resins, however, resulted not only in the reduction in the thermal stability of the blended BDM resin but also elevation of the coefficients of thermal expansion. The changes in thermal/mechanical properties of the blends were found to be proportional to the amounts of m-PEG incorporated. It was observed that the curing behavior, and thermal and mechanical properties, of the blends were independent of the molecular weight of the PEG segment.
Polymer-plastics Technology and Engineering, 1999
Starting from two aromatic diamines carrying meta phenoxy linkages, 3,Y-[2,6-pyridinediylbis(oxy)]bisbenzeneamine (BAPPY) and 3,Y-[ 1,3-phenylenebis(oxy)]bisbenzeneamine (BAPB)we have synthesized two thermoplastic linear polyimides by polycondensation with 3,3';4,4' benzophenone dianhydride (BTDA) and two thermosetting bismaleimides by condensation with maleic anhydride. The characterization of these different compounds was achieved by d.s.c., t.m.a., t.g.a, and d.m.a. Each linear polyimide was then mixed with the corresponding bismaleimide, or with another bismaleimide having a different chemical structure, 1,1'-(methylenedi-l,4-phenylene)bis(1H-pyrrole-2,5-dione). The mixtures blended in N-methylpyrrolidone solution were cast onto glass plate and were thermally dried following a cure cycle of 1 h at 100°C, 1 h at 150°C and 1 h at 200°C. This did not allow the polymerization ofmaleimide groups. The thermomechanical analysis of the resulting films showed a reduction of the glass transition temperature of polyimides in agreement with a plasticizing by bismaleimides. (Keywords: 3,3'-[2,6-pyridinediylbis(oxy)]bisbenzeneamine; 3,3'-[1,3-phenylene bis(oxy)]bisbenzeneamine; polyimide; bismaleimide; blends of polyimide and bismaleimide; thermomechanical analysis) BAPPY : X = N BAPB : X=CH Lo o jn
Journal of Applied Polymer Science, 1999
Novolac resin/poly(n-butyl methacrylate), P(n-BMA), sequential interpenetrating polymer networks (both semi and full types) were prepared and characterization of the various compositions (up to 40% by weight of PF incorporation) was performed in terms of mechanicals, namely, ultimate tensile strength (UTS), percentage elongation at break (% E.B.), modulus, and toughness. Thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis (TGA). Crosslink densities of the IPNs were calculated using Flory-Rehner equation. The morphological features were studied through scanning electron microscope. There was a gradual decrease of mod-ulus and UTS with consequent increases in % E. B. and toughness with increasing proportions of P(n-BMA). An inward shifting and lowering of the glass transition temperatures of the IPNs (compared with that of pure phenolic resin) with increasing proportions of P(n-BMA) were observed. The TGA thermograms exhibit two-step degradation patterns. A typical cocontinuous bi-phasic morphology is evident in the micrographs.
Journal of Applied Polymer Science, 2015
ABSTRACT A novel thermally reversible cross-linked polymer has been synthesized by a Diels-Alder (DA) reaction between bis(4-maleimido-phenyl)fluorene (cBMI) and tetrakis-furan monomers (4F) under microwave (MW) irradiation. The ultimate aim of this work was the preparation of a thermosetting material recyclable by a simple thermal treatment. The use of the MW irradiation was necessary because under thermal conditions the DA polymerization could lead to materials only partially cross-linked for a not desired equilibrium between DA and retro-DA processes induced by the high temperature. The easy thermal degradation of this cross-linked material was ascertained by appropriate experiments. Moreover, to better study the involved reactions of formation and decomposition, a more simple model-compound was also synthesized. The reported data confirm the recyclability of the synthesized cross-linked polymer by simply heating with the possibility of a regeneration of the polymer network by a further MW irradiation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42314.
A renewable approach to thermosetting resins
Reactive and Functional Polymers, 2013
This is a review of recent developments of thermostable resins derived basically from vegetable oils. Natural vegetable oils have been transformed in polymers following three main routes. The first is the direct polymerization through the double bonds of the fatty acid chain. The cationic copolymerization of soybean oil with styrene, divinylbenzene and different amounts of styrenic monomers containing Si, B and P has been used to produce materials with improved flame retardant properties. The second route is the functionalization of the triglyceride double bonds to introduce readily polymerizable groups: The singlet oxygen photoperoxidation of the allylic positions of high oleic sunflower oil has been used to produce hydroperoxide-containing triglycerides that were dehydrated or reduced to produce respectively enone-and hydroxyl-containing triglycerides. The enone containing derivative has been chemically crosslinked with aromatic diamines through aza-Michael reactions leading to quinoline containing thermosets. The hydroxyl-containing triglycerides have been crosslinked radically prior the introduction of acrylate groups to produce conventional and flame retardant acrylate resins. The third route explored consists of using plant oil-derived chemicals like 10-undecenoic and oleic acids to produce tailor made monomers. Acyclic diene metathesis (ADMET) polymerization has been applied to prepare a set of thermosetting polyesters with flame retardant properties. Moreover thiol-ene ''click'' coupling has been used to prepare carboxylic monomers that have been explored to produce thermosetting polyanhydrides for fast drug delivery systems. A set of tailored polyols from the products of coordinative polymerization of the methyl epoxyoleate and the cationic ring opening polymerization of fatty acid-derived 2oxazolines were also prepared. These polyols have been used to produce different thermosetting polyuretanes with a wide range of properties and characteristics. Finally, some recent research in producing benzoxazine thermosetting resins applying this renewable approach is presented. The benzoxazines based on diphenolic acid, a derivative of levulinic acid, are studied.
Journal of Polymer Science Part A: Polymer Chemistry, 2008
Scandium, ytterbium, and lanthanum triflates and boron trifluoride monoethylamine were used as cationic initiators to cure a mixture 2:1 (mol/mol) of diglycidylether of bisphenol A (DGEBA) and 7,7-dimethyl-6,8-dioxaspiro[3.5]nonane-5,9-dione (MCB). The evolution of the epoxy and lactone during curing and the linear ester groups in the final materials were evaluated by Fourier Transform Infrared in the attenuated-total-reflection mode. The kinetic parameters of the curing process were calculated from DSC analysis applying isoconversional procedures. The shrinkage on curing and the thermal degradability of the materials on varying the initiator used were evaluated. The expandable character of MCB was confirmed. The materials obtained were more degradable than conventional epoxy resins due to the tertiary ester groups incorporated in the network by copolymerization.
New improved thermosets obtained from DGEBA and a hyperbranched poly(ester-amide)
Polymer, 2009
The influence on the curing process of a commercial hydroxy-functionalized hyperbranched poly(esteramide) (HBP) Hybrane Ò S1200 on diglycidylether of bisphenol A (DGEBA) was studied. By Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) the curing reaction was studied and the covalent incorporation of the modifier in the matrix was proved. By Thermomechanical Analysis (TMA) the reduction of the contraction after gelation on changing the S1200 proportion was observed. The incorporation of S1200 increased the glass transition temperature (T g ) and reduced the overall shrinkage, specially after gelation. The modified materials were more thermally degradable than neat DGEBA thermosets. Thermal expansion coefficient, Young's modulus, impact strength and microhardness were improved without compromising the thermomechanical characteristics. The water uptake behaviour was also evaluated.
2016
Three cyanate ester monomer or oligomer species: 2,2-bis(4-cyanatophenyl)propane 1, 1-1-bis(4-cyanatophenyl)ethane (2), and the oligomeric phenolic cyanate (Primaset™ PT30) (3), are blended in various ratios with bis(4-maleimidophenyl)methane, (4), to form binary and ternary mixtures (11 in total) and cured, in the absence of catalysts (3 K min− 1 to 150 °C + 1 h; 3 K min− 1 to 200 °C + 3 h), followed by a post cure (3 K min− 1 to 260 °C + 1 h). The use of liquid monomer, (2), offers the possibility of liquid processing in blends containing minority compositions of bismaleimide. Glycidylmethacrylate is explored as a reactive diluent (2.5–10 wt%) to linked interpenetrating network polymer structures comprising cyanate ester and bismaleimide components with glass transition temperatures of 267–275 °C, depending on composition; the onset of thermo-oxidative degradation ranges from 386 to 397 °C. When a binary blend of (2) and (3) (with the former in the minority) is co-cured with (4), ...