Some problems of the thermal degradation of poly(vinyl chloride)

Transparent thermoplastic polymers that exhibit no birefringence are ideal for optical components such as optical films for liquid crystal displays and various lenses. Copolymerization of a positive birefringent monomer with a negative monomer is an effective technique for obtaining low birefringent polymers, especially zero‐photoelastic birefringence polymers that exhibit no photoelastic birefringence even during elastic deformation. We prepared four types of trifluoromethyl‐substituted polystyrenes. By substituting hydrogens at the ortho or meta positions of the benzene ring of polystyrene, we demonstrated that poly(2‐(trifluoromethyl)styrene), poly(3‐(trifluoromethyl)styrene), and poly(3,5‐bis(trifluoromethyl)styrene) had negative photoelastic coefficients. However, poly(4‐(trifluoromethyl)styrene) had a positive photoelastic coefficient similar to that of polystyrene. Based on these results, we synthesized a zero‐photoelastic birefringence polymer of poly(2‐(trifluoromethyl)styrene‐co‐4‐(trifluoromethyl)styrene) (55/45 wt.) exhibiting no photoelastic birefringence in elastic deformation, in which the positive photoelastic birefringence of the poly(4‐(trifluoromethyl)styrene) unit was compensated for by the negative photoelastic birefringence of the poly(2‐(trifluoromethyl)styrene) unit. The discovery of polymers having negative photoelastic coefficients is valuable for the design and synthesis of zero‐photoelastic birefringence polymers. The four types of trifluoromethyl‐substituted polystyrenes are promising optical materials because they have high transparency (transmittance > 89–92% for 27–34‐µm thickness films) in the visible and near‐infrared regions and a high decomposition temperature of approximately 400°C. Copyright © 2016 John Wiley & Sons, Ltd.

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“…The polymerization conversions were in the range of 8–14 wt%. The monomer reactivity ratios were calculated using the Kelen–Tüdős (K–T) method …”

Section: Methodsmentioning

confidence: 99%

Effect of trifluoromethyl substituents on birefringence of polystyrene

Tagaya

Koike

et al. 2016

Polymers for Advanced Techs

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“…In the dataset available in the Polymer Handbook the reactivity ratios are either taken directly from the reported sources, where any one of a number of different techniques may have been used, or are calculated based on the available data using the Kelen-Tudos method 49,50 (roughly two thirds of the entries). In the majority of cases the modified version of the Kelen-Tudos method that takes into account conversion by taking an average monomer composition has been used.…”

Section: Papermentioning

confidence: 99%

An artificial neural network to predict reactivity ratios in radical copolymerization

Farajzadehahary,

Telleria-Allika,

Asua

et al. 2023

Polym. Chem.

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“…If one knows these concentrations, 13 C NMR can be used to estimate the composition of the polymer, and if the polymer is produced in conditions with no composition drift, Equation (3) can be used to fit the data and obtain the true reactivity ratios. There are of course other methods, such as the Fineman-Ross [1] or Kelen-Tudos [2] methods, that take slightly different approaches, but that also rely on values of the copolymer composition, and the fractions of monomer at the active sites. In other words, regardless of how one estimates the true reactivity ratios, the reliability of the values will depend greatly on the precision of the NMR measures and on the accuracy of the estimation of the monomer and comonomer fractions at the active sites.…”

Section: Introductionmentioning

confidence: 99%

Estimation of Reactivity Ratios for Olefin Polymerization Catalysts—On the Importance of Thermodynamics

Ishola

McKenna

2022

Macro Reaction Engineering

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A systematic study of the impact of gas phase composition on the estimation of the reactivity ratios of a Ziegler–Natta catalyst during the gas phase copolymerization of ethylene with 1‐butene and 1‐hexene has been carried out. The results of the study show that if one uses a realistic equation of state to estimate the co‐ and anti‐solubility effects of multiple species in the gas phase, one can obtain a unique value of the reactivity ratio pair from any number of experiments. However, it is found that using only binary solubility data and ignoring the impact of chemically inert species on solubility will lead to the estimate of composition‐dependent reactivity ratio pairs.

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Some problems of the thermal degradation of poly(vinyl chloride)

Cited by 9 publications

References 8 publications

Effect of trifluoromethyl substituents on birefringence of polystyrene

Effect of trifluoromethyl substituents on birefringence of polystyrene

An artificial neural network to predict reactivity ratios in radical copolymerization

Estimation of Reactivity Ratios for Olefin Polymerization Catalysts—On the Importance of Thermodynamics

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