Control of shrinkage and residual styrene of unsaturated polyester resins cured at low temperatures: I. Effect of curing agents

Cao, Xia; Lee, L.James

doi:10.1016/s0032-3861(03)00014-4

Cited by 66 publications

(38 citation statements)

References 17 publications

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“…It is Table 2 DSC data of the cure reaction of unsaturated epoxy polyesters based on EG, BDO, or HDO: styrene (20 wt%) initiated by different BPO concentration (0.5-3.0 wt%) Influence of tertiary aromatic amines 989 well known that oxygen is an efficient inhibitor of conventional radical polymerization [19]. Probably due to lower viscosity of high styrene content samples, faster oxygen diffusion from the resin in DSC chamber causes a decrease in the induction period of the cure process and thus lower T onset [20,21]. Moreover, it is reasonable to expect a constant consumption rate of both monomers at lower styrene content in the composition.…”

Section: Resultsmentioning

confidence: 99%

The influence of tertiary aromatic amines on the BPO initiated cure of unsaturated epoxy polyesters with styrene studied by non-isothermal DSC

Worzakowska

2011

J Therm Anal Calorim

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The influence of tertiary aromatic amines on the course of BPO initiated cure reaction of unsaturated epoxy polyesters with different styrene content has been studied by non-isothermal differential scanning calorimetry. Unsaturated epoxy polyesters prepared from cyclohex-4-ene-1,2-dicarboxylic anhydride, maleic anhydride and suitable aliphatic glycol: ethylene glycol or 1,4-butanediol or 1,6-hexanediol were dissolved in vinyl monomer (styrene) resulting in a styrene content of 20-80% by weight. The styrene solutions of polyesters were subjected to the cure reaction with suitable curing agent: benzoyl peroxide (BPO) used in various concentration (0.5-3.0 wt%) or the mixture of BPO/stoichiometric ratio of chosen tertiary aromatic amines: (N,N-dimethylbenzylamine (BDMA) or 2,4,6-tri(dimethylaminomethyl) phenol (DMP-30). The curing characteristic such as: temperature of the cure initiation (T onset ), peak maximum temperature (T max ), final cure temperature (T end ), heat generated during the cure reaction (DH) were evaluated. It has been found that the course of the cure reaction depended on the styrene content in prepared compositions and the initiating system used. The performed investigations confirmed that one of the applied tertiary aromatic amine: BDMA was an effective promoter for BPO decomposition process, causing a decrease in characteristic curing temperatures of unsaturated epoxy polyesters with styrene. The organic peroxide-amine interactions caused the promotion of BPO decomposition to benzoyloxy radicals at lower temperatures and thus accelerated the copolymerization process. However, DMP-30 was a very sluggish promoter for BPO decomposition, probably due to the presence of both hydroxyl group, their ortho-position to two of three amine groups and their branched structure. The redox reaction between BPO and DMP-30 probably resulted in non-radical products or radical formation which was incapable of initiating the polymerization reaction.

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Section: Resultsmentioning

confidence: 99%

The influence of tertiary aromatic amines on the BPO initiated cure of unsaturated epoxy polyesters with styrene studied by non-isothermal DSC

Worzakowska

2011

J Therm Anal Calorim

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“…Also hybrid networks consisting of UPRs and polyurethanes were investigated by many authors. In any case, an improvement of properties by incorporating polyurethanes into crosslinked UPR [24,85,86] was found.…”

Section: Interpenetrating Polymer Networkmentioning

confidence: 90%

“…In a paper by Cao and Lee [85], the use of a commercial carboxylated poly(vinyl acetate) as a low-profile additive for a cold-curing UPR system with a styrene monomer was described. A dual-initiator system consisting of methylethylketone peroxide and tert-butylperoxybenzoate with a cobalt promoter and benzoquinone inhibitor was applied.…”

Section: Compositions With Thermoplastic Additivesmentioning

confidence: 99%

“…The composites thus prepared exhibited enhanced flexural and compressive module, whereas the flexural strength and ultimate strain were decreased. The system consisting of UP, styrene and poly(vinyl acetate) as the low-profile additive was investigated [85]. Volume shrinkage was measured of the resin cured with dual-initiator systems at lower (35 • C) and higher (100 • C) temperature.…”

Section: Compositions With Thermoplastic Additivesmentioning

confidence: 99%

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Unsaturated Polyester Resins: Chemistry and Technology

Penczek

Czub

Pielichowski

2005

Advances in Polymer Science

105

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“…9a and b, contrarily to the smooth external morphology previously encountered on the unfilled particles. This may be a consequence of silica presence in combination with slight retraction of the polymer matrix upon curing [15,16]. Internal particle vesiculation (Fig.…”

Section: Table 1 Ftir Peak Intensity Ratiosmentioning

confidence: 99%

Physicomechanical characterization of monodisperse multivesiculated polyester particles

Fidalgo¹,

Mendes²,

Magalhães³

2014

European Polymer Journal

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This work describes physicomechanical properties of low-density polyester particles with multialveolar inner morphology, obtained via a water/oil/water double emulsion process. Monodisperse particle diameters were produced thanks to the use of a microchannel T-junction device for droplet generation. The drying conditions tested showed that rapid water evaporation at 120 o C, combined with slow diffusion towards the exterior, causes internal fracture and particle deformation. Interestingly, all particles present virtually identical internal damage and external deformation features under these drying conditions, demonstrating the uniformity in internal structures. Drying at 70 o C allows for efficient water removal with no damage. Thermomechanical transitions and thermal stability were analyzed by dynamic mechanical analysis (DMA in single-particle compression mode), dynamic scanning calorimetry (DSC) and thermogravimetry (TG). The effectiveness of curing conditions was evaluated by FTIR and DSC, allowing to identify the need of a thermal post-treatment for consumption of residual styrene. The consequent increase in degree of crosslinking produced a positive shift in glass transition temperature measured by DMA. Finally, mechanical reinforcement of the multivesiculated polyester particles was obtained by loading the polymer with surface-modified fumed silica, yielding 75% increase in storage modulus.

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Control of shrinkage and residual styrene of unsaturated polyester resins cured at low temperatures: I. Effect of curing agents

Cited by 66 publications

References 17 publications

The influence of tertiary aromatic amines on the BPO initiated cure of unsaturated epoxy polyesters with styrene studied by non-isothermal DSC

The influence of tertiary aromatic amines on the BPO initiated cure of unsaturated epoxy polyesters with styrene studied by non-isothermal DSC

Unsaturated Polyester Resins: Chemistry and Technology

Physicomechanical characterization of monodisperse multivesiculated polyester particles

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