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The kinetics of butyl acrylate solution polymerization up to high conversion are studied both experimentally and theoretically. New expressions taking into account both inter‐ and intra‐molecular transfer to polymer are derived for polymerization rate, average chain‐length and branching level. These expressions are used for comparative analysis of these two chain transfer events and for evaluation of the backbiting rate coefficient, kbb, and the constant of chain transfer to solvent (xylene), CtrS. Using batch experiments performed at 50, 60 and 70 °C, the Arrhenius parameters for kbb and CtrS are estimated to be, respectively, A(kbb) = (7.4 ± 1.5) × 107 s−1, Ea(kbb) = (32.7 ± 0.5) kJ · mol−1 and A(CtrS) = 10.5 ± 3.5, Ea(CtrS) = (26.9 ± 1.9) kJ · mol−1.

Butyl acrylate solution polymerization has been studied at 80-170 8C over a range of monomer and initiator levels. A PREDICI model has been developed to describe the experiments, taking into account chain backbiting, b-scission, and addition of macromonomer. The model is used to estimate Arrhenius parameters for the rate coefficients of b-scission [A(k b ) ¼ (1.49 AE 0.28) Â 10 9 s À1 , E a (k b ) ¼ 63.9 AE 0.9 kJ Á mol À1 ], for the ratio of the termination rate coefficients of secondary and midchain radicals Aðk t =k t t Þ ¼ 0:74 AE 0:08; E a ðk t =k t t Þ ¼ Àð11:2 AE 0:5ÞkJ Á mol À1 Â Ã and for the constant of chain transfer to xylene [A(C trS ) ¼ 107 AE 13, E a (C trS ) ¼ 35.4 AE 0.8 kJ Á mol À1 ] by fitting simulated dependencies to the experimental data.

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MmWave radio, although instrumental for achieving the required 5G capacity Key Performance Indicators (KPIs), necessitates the need for a very large number of Access Points, which places an immense strain on the current network infrastructure. In this article, we try to identify the major challenges that inhibit the design of the Next Generation Fronthaul Interface in two upcoming distinctively highly dense environments: i) in Urban 5G deployments in metropolitan areas and ii) in ultra-dense Hotspot scenarios. Secondly, we propose a novel centralized and converged analog Fiber-Wireless Fronthaul architecture, specifically designed to facilitate mmWave access in the above scenarios. The proposed architecture leverages optical transceivers, optical add/drop multiplexers and optical beamforming integrated photonics towards a Digital Signal Processing analog fronthaul. The functional administration of the fronthaul infrastructure is achieved by means of a packetized Medium Transparent Dynamic Bandwidth Allocation protocol. Preliminary results show that the protocol can facilitate Gbps-enabled data transport while abiding to the 5G low-latency KPIs in various network traffic conditions.

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