Current Status of Unsaturated Polyester Resins

Malik, Mona; Choudhary, Veena; Varma, I. K.

doi:10.1081/mc-100100582

Cited by 117 publications

(68 citation statements)

References 141 publications

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“…In addition, the bulk polymerization method employed for the synthesis of the UPs does not require the use of toxic solvents as other available processes (e.g. azeotropic distillation [14,15]). It should be pointed out that, to the best of our knowledge, the synthesis of an UP totally based on renewable monomers has never been reported to afford UPRs (crosslinked with Sty) that have thermal and mechanical properties similar to those of a commercial UPR.…”

Section: Introductionmentioning

confidence: 99%

Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

Costa¹,

Fonseca²,

Moniz³

et al. 2017

Express Polym. Lett.

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Abstract. The main goal of this work was the development of fully biobased unsaturated polyesters (UPs) that upon crosslinking with unsaturated monomers (UM) could lead to greener unsaturated polyester resins (UPRs) with similar thermomechanical properties to commercial fossil based UPR. After the successful synthesis of the biobased UPs, those were crosslinked with styrene (Sty), the most commonly used monomer, and the influence of the chemical structure of the UPs on the thermomechanical characteristics of UPRs were evaluated. The properties were compared with those of a commercial resin (Resipur 9837 ® ). The BioUPRs presented high gel contents and contact angles that are similar to the commercial resin. The thermomechanical properties were evaluated by dynamic mechanical thermal analysis (DMTA) and it was found that the UPR synthesized using propylene glycol (PG), succinic acid (SuAc) and itaconic acid (ItAc) presented very close thermomechanical properties compared to the commercial resin.

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Section: Introductionmentioning

confidence: 99%

Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

Costa¹,

Fonseca²,

Moniz³

et al. 2017

Express Polym. Lett.

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“…To reduce the void contents, long production times are necessary. As a result, a viscosity of 500 cP is considered about the maximum for most inexpensive liquid molding techniques (1,22). Equation 5 can be rearranged to solve for the minimum styrene content required to achieve such a viscosity for given values of M n .…”

Section: Effect Of Vinyl-ester Molecular Weight and Styrene Contentmentioning

confidence: 99%

“…However, the use of these resins is limited because of their low fracture toughness (~100 J/m 2 ), higher viscosity (400 cP), and higher cost relative to Unfortunately, decreasing the styrene content in vinyl-ester resins does not offer an acceptable solution to this problem. As the styrene content is reduced, the resin viscosity increases, making it difficult to use inexpensive molding techniques (1,9). In addition, Dow Derakane 441-400 uses 27% less styrene than Derakane 411-350 (6) but has less than half the fracture toughness (5,8).…”

Section: Introductionmentioning

confidence: 99%

“…Vinyl-ester resins are used to make polymer matrix composites in military and commercial applications because of their high modulus, high strength, high glass transition temperature, low weight, and low cost (1,2). These resins have superior properties relative to unsaturated polyester systems and are less expensive and easier to process than epoxy systems (1).…”

Section: Introductionmentioning

confidence: 99%

“…To reduce the void contents, long production times are necessary. As a result, a viscosity of 500 cP is considered about the maximum for most inexpensive liquid molding techniques (1,22). The use of bimodal blends of vinyl-esters and fatty-acid monomers to reduce styrene content in vinyl-ester resins are acceptable solutions.…”

Section: Introductionmentioning

confidence: 99%

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Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid-Based Resins

LaScala¹,

Jeyarajasingam²,

Winston³

et al. 2005

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)December 2005 ARL-TR-3681 SPONSOR/MONITOR'S ACRONYM(S) 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTStyrene and methacrylated fatty acid (MFA) monomers were used as reactive diluents in the vinyl ester resins. The viscosities of these resins were measured as a function of reactive diluent content and type, temperature, and vinyl ester molecular weight to determine the operating window for composite manufacture. The viscosity decreased exponentially with reactive diluent content. Styrene and MFA monomers affected the viscosity in the same manner, but not to the same extent. The viscosities of resins using both diluents were accurately predicted using a logarithmic rule of mixtures from the two-component viscosity functions. The viscosity increased exponentially and predictably as a function of the vinyl ester number average molecular weight. Increasing the temperature decreased the viscosity in an Arrhenius manner. The activation energy for viscous flow decreased linearly as the diluent content increased, but was unaffected by vinyl ester molecular weight, fatty acid chain length, and unsaturation level. Overall, the resin viscosity was modeled as simple functions of the resin temperature, vinyl ester molecular weight, styrene content, MFA content, MFA chain length, and MFA unsaturation level, which are all known quantities for a formulated resin. Therefore, the operating window for various liquid molding operations was predicted for standard DGEBA-based vinyl ester resins and low VOC/HAP resins. SUBJECT TERMSlow VOC vinyl esters, styrene, viscosity

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Sheet Molding Compounds

Orgéas,

Dumont

2012

Wiley Encyclopedia of Composites

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Sheet molding compounds (SMC) are fiber‐reinforced thermosetting semifinished products. They are produced in thin uncured and thickened sheets that can be handled easily before their forming process. To a larger extent, SMC is a generic term that designates such types of compounds together with the process to convert them into large composite parts, which mainly display shell‐like geometry. This process is usually compression molding. SMC are widely used in a large diversity of fields of applications (aerospace, agricultural, rail and marine, electrical and energy, domestic appliance, building and construction, and medical sectors), but the automotive and truck industries remain the drivers of SMC technology. After a short introduction, this article gives successively detailed descriptions of (i) the materials used in SMC, (ii) their compounding, (iii) the compression molding process, (iv) the final properties of SMC, and (v) SMC recycling.

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Current Status of Unsaturated Polyester Resins

Cited by 117 publications

References 141 publications

Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid-Based Resins

Sheet Molding Compounds

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