Influence of the molecular weight on the thermal and mechanical properties of ethylene/norbornene copolymers

Ekizoglou, Nikos; Thorshaug, Knut; Cerrada, María L.; Benavente, Rosario; Pérez, Ernesto; Pereña, José M.

doi:10.1002/app.12526

Cited by 13 publications

(15 citation statements)

References 21 publications

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“…Ekizoglou et al [92] also studied the thermal properties of laboratory-made ENCs, having a norbornene molar fraction varying from 0.45 to 0.47. They showed that those ENCs had, respectively, T g varying from 108 to 123°C (from DSC measurements) or from 132 to 143°C (from DMTA measurements).…”

Section: Cyclic Olefin Copolymers (Coc) Development Of Cyclic Olefin mentioning

confidence: 97%

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Physico-chemical ageing of ethylene–norbornene copolymers: a review

et al. 2017

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The main object of this report is to review and summarize the current state of the scientific literature relating to physico-chemical ageing of ethylene-norbornene copolymers (ENCs). These processes occur through different means such as photodegradation under the effect of ultraviolet radiation, temperature and ionizing radiation (under air or oxygen). In most cases ageing causes chains scissions that lead to the creation of degradation compounds that exhibit high mobility, corresponding to their low molecular weight and/or high polarity. Cross-linking can also occur, leading to the modification of mechanical properties. The presence of oxygen during ageing is of great importance for the physico-chemical modifications of those polymers in terms of oxidation and thermal stability. ENCs belong to cyclic olefin copolymers (COC) class, whose synthesis was developed in the late 1950s. Nevertheless, commercial applications are relatively new. They attract growing interest in different fields, due to their very useful physical and chemical properties such as transparency, heat and chemical resistance, low permeability to gas as well as biocompatibility. In the literature, a large number of papers deal with the synthesis and characterization of different grades of ENC, but only a few deal with the effects of ageing on these materials. This literature review consists of a summary of the main milestones in the development of COC as well as of cyclic olefin polymers (COP), a review of main techniques for predicting ageing, degradation of additives and interaction between COC/COP and contact environment as well as toxicity of the extractables.

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Section: Cyclic Olefin Copolymers (Coc) Development Of Cyclic Olefin mentioning

confidence: 97%

“…This type of ageing has been referenced by several authors [91][92][93][94][95][104][105][106]. Thermal ageing is performed to study the thermal stability and the thermal properties of materials.…”

Section: Ageing By Thermal Oxidationmentioning

confidence: 99%

Physico-chemical ageing of ethylene–norbornene copolymers: a review

et al. 2017

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“…Cyclic olefin copolymers (COCs) are a promising type of optical materials for their excellent performance in applications. The effects of copolymer composition, sequence distribution, and molecular weight on thermal properties of COC have been studied by many groups in the past decade 1–17. However, there are few reports on the relationships between chain microstructure and optical/surface properties.…”

Section: Introductionmentioning

confidence: 99%

“…The effects of copolymer composition, sequence distribution, and molecular weight on thermal properties of COC have been studied by many groups in the past decade. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, there are few reports on the relationships between chain microstructure and optical/surface properties. Ou and Hsu 18 prepared COC/SiO 2 nanocomposites containing 1, 5, 10, and 15 wt % SiO 2 nanoparticles through solution blending and studied addition of SiO 2 on light transparency of composites.…”

Section: Introductionmentioning

confidence: 99%

Influence of chain microstructure on ethylene–norbornene copolymer film properties

Yao

Chen

et al. 2011

J of Applied Polymer Sci

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The effects of copolymer composition, copolymer composition distribution, and polar a-olefin incorporation on transparency, refractive index, and hydrophilicity of resultant ethylene-norbornene copolymer films were investigated. It has been found that the transparency is mainly determined by the copolymer composition distribution. The samples having uniform compositions gave better transparency. However, the copolymer composition distribution had little effect on refractive index. The refractive index increased linearly with increasing norbornene content. Furthermore, the incorporation of polar a-olefin with long carbon chain improved refractive index and hydrophilicity of the films.

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“…30 The molecular weight of ENC (if not very high) also plays an important role in the thermal behaviors of the materials. 31 For the next generation optical applications, the ENC materials must have high NB content and uniformity in chain microstructure for higher T g and better transparency. To achieve this goal, both sequence length distribution and copolymer composition distribution (CCD) must be carefully designed and controlled.…”

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confidence: 99%

Model development for semicontinuous production of ethylene and norbornene copolymers having uniform composition

Cao

Yao

et al. 2009

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).Terminal and penultimate models for controlling copolymer composition distribution (CCD) in ethylene and norbornene (NB) copolymerization were developed by taking into account the variation of active site concentration with the initial comonomer ratio. The models were validated by batch polymerization experimental data. The terminal model gave better correlation with the composition data whereas the penultimate model had a better fit to the rate data. The terminal model was then used to design NB feeding policies in semicontinuous processes for targeted CCD profiles. Based on the model results, a series of ethylene-NB copolymers with various NB contents were prepared. With the same NB content, the semicontinuous process produced a uniform composition, whereas the batch process yielded broad CCD. The batch samples had lower T g values and broader transition ranges, even yielded crystalline materials. In contrast, the semicontinuous samples overcame the disadvantages. (a) Copolymer yield vs. reaction time; (b) NB conversion vs. reaction time. Conditions: catalyst concentration 5 4 3 10 25 mol/l, Al/Zr 5 1500, toluene 5 50 ml, P 5 1 atm, T 5 708C, initial NB/E 5 19.6, total reaction time 5 90 min. Conditions: catalyst concentration 5 4 3 10 25 mol/l, Al/Zr 5 1500, toluene 5 50 ml, P 5 1 atm, T 5 708C.Figure 5. Copolymer yield/NB conversion vs. reaction time in the batch process for initial NB/E 5 1.3 (For the model calculation, c * varies with the initial NB/E according to Figure 4). (a) Copolymer yield vs. reaction time; (b) NB conversion vs. reaction time. Conditions: catalyst concentration 5 4 3 10 25 mol/l, Al/Zr 5 1500, toluene 5 50 ml, P 5 1 atm, T 5 708C, initial NB/E 5 1.3, total reaction time 5 10 min.

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Influence of the molecular weight on the thermal and mechanical properties of ethylene/norbornene copolymers

Cited by 13 publications

References 21 publications

Physico-chemical ageing of ethylene–norbornene copolymers: a review

Physico-chemical ageing of ethylene–norbornene copolymers: a review

Influence of chain microstructure on ethylene–norbornene copolymer film properties

Model development for semicontinuous production of ethylene and norbornene copolymers having uniform composition

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