Retraction

By this notice the Editor and Publisher of the Journal of Applied Polymer Science retract from publication the following two articles: "Effect of Various Inorganic Fillers on the Friction and Wear Behaviors of Polyphenylene Sulfide," Laigui Yu, Weimin Liu, and Qunji Xue, Journal of Applied Polymer Science,Volume 68, No. 10, June 6, 1998, pp. 1643-1650 "Transition Between Transient and Steady-State Wear in the Sliding of Poly(phenylene sulfide) Against a Tool Steel Counterface," Laigui Yu, Weimin Liu, and Qunji Xue, Journal of Applied Polymer Science, Volume 69, No. 6, August 8, 1998, pp. 1099-1106 The reason for this action is that the intellectual property of the article does not belong to the authors cited. Rather it was taken without permission from the Master's Thesis (Iowa State University) of Qing Zhao. Mr. Zhao and Professor Shyam Bahadur have submitted a paper based on Mr. Zhao's Master's Thesis to the Journal of Wear. The Editor and the Publisher of the Journal of Applied Polymer Science regret the occurrence of this unfortunate incident.     

Retraction

By this notice the Editor and Publisher of the Journal of Applied Polymer Science retract from publication the following two articles: “Effect of Various Inorganic Fillers on the Friction and Wear Behaviors of Polyphenylene Sulfide,” Laigui Yu, Weimin Liu, and Qunji Xue, Journal of Applied Polymer Science, Volume 68, No. 10, June 6, 1998, pp. 1643–1650 “Transition Between Transient and Steady-State Wear in the Sliding of Poly(phenylene sulfide) Against a Tool Steel Counterface,” Laigui Yu, Weimin Liu, and Qunji Xue, Journal of Applied Polymer Science, Volume 69, No. 6, August 8, 1998, pp. 1099–1106 The reason for this action is that the intellectual property of this article does not belong to the authors cited. Rather it was taken without permission from the Master's Thesis (Iowa State University) of Qing Zhao. Mr. Zhao and Professor Shyam Bahadur have submitted a paper based on Mr. Zhao's Master's Thesis to the Journal of Wear. The Editor and the Publisher of the Journal of Applied Polymer Science regret the occurrence of this unfortunate incident.     

Retraction

Retraction: AKM Asif Iqbal, Muhamad Zami Bin Abdul Hamid, A. K. M. Parvez Iqbal (2020) Effect of porosity on the microstructure and mechanical properties of YSZ thermal barrier coating densified by spark plasma sintering (SPS). International Journal of Applied Ceramic Technology: https://doi.org/10.1111/ijac.13599 The above article, published online on 9 August 2020 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the outgoing Editor-in-Chief, Monica Ferraris, the incoming Editor-in-Chief, Young-Wook Kim, and Wiley Periodicals, LLC. The retraction has been agreed due to unattributed overlap between images presented as original data in this article and the following article published in Ceramics International, “Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering” by Arnaud Fregeac, Florence Ansart, Serge Selezneff, Claude Estournès, Volume 45, 2019, pages 23740-23749.     

Retraction of polypropylene tape

Retraction measurements have been made on 50 μm thick polypropylene tapes drawn on a yarn line under a variety of conditions. Small samples were annealed in silicone oil for different periods at temperatures up to the melting point. The retraction data were found to be described by a relation of the form R(%) = A + B log t, where A and B are constant for a given temperature, A being the intercept on the retraction axis for t = 1. As the temperature is increased towards the melting point, A increases, slowly at first and then much more rapidly. On the other hand, B reaches a maximum at a temperature T_k, and then decreases as the temperature is increased further. T_k corresponds to the point at which A, which represents a virtually instantaneous retraction as the sample reaches temperature, begins to increase rapidly. T_k promises to be useful in that it represents the susceptibility of a given polymer to retraction and corresponds fairly closely to the original draw temperature if the tape has not been heat set. D.s.c. analysis has demonstrated that the mechanism responsible for the instantaneous component of retraction is the partial melting out of crystallites. The small logarithmic retraction which is dominant below T_k is seen as resulting from a thermally activated process within the crystallites. The approach has enabled the effect of pre-anneals and heating rates to be understood and has also led to a general prediction of retraction behaviour under conditions of continuous heating.     

Retraction of the claim of ring expansion polymerization of isobutylene

Some three years ago in a preliminary report from this laboratory we have proposed that the polymerization of isobutylene (IB) by the -tolyl--valerolactone/BCl₃ initiating system in CH₃Cl or CH₂Cl₂ diluents at-30°C proceeds in a living manner by an unusual ring expansion mechanism and produces macrocyclic polyisobutylenes (PIBs) [1]. Extensive follow-up research confirmed the living nature of the polymerization, however, has failed to confirm the results of a key preliminary experiment upon which the proposition of macrocyclic polymer structure was based. Thus the results of a comparative hydrolysis/GPC experiment carried out with a relatively low molecular weight (Mn=5,400) PIB at -30°C under a blanket of N₂ which gave a lower apparent molecular weight after hydrolysis than the original sample before hhydrolysis, could not be confirmed with higher molecular weight samples, i.e., with Mn=12,000, 17,000 and 30,000. As a consequence we wish to retract our earlier claim in regard to the synthesis of macrocyclic PIBs by certain lactone/BCl₃ initiating systems but maintain that these polymerizations proceed in a living manner and yield asymmetric telechelic PIBs, e.g.,-chloro--carboxyl-PIBs [2].