Preparation of large‐sized graded‐index polymer preform

Abstract

ABSTRACT:In this article, an improved method was put forward to overcome the defect of interfacial-gel polymerization technique. The cause of the defects was analyzed, and the factors of reaction conditions on formation of the graded-index (GI) polymer preform (i.e., reaction temperature and atmosphere pressure) were investigated. Highperformance large-sized GI polymer preform was prepared by this improved technique, in which diphenyl sulfide was used as higher refractive index molecules.

Progress in preparation of high‐performance and multi‐functional polymer foams

“…The combination of scCO 2 foaming and microwave sintering technology resulted in the formation of a three‐dimensional polymer/filler skeleton (Figure 11A1). 53 This skeleton endowed the foam parts with exceptional antistatic and mechanical properties, such as a short‐circuit current of 3.0 nA and a superior compressive strength of 4.64 MPa at 10% strain. These properties exceeded those reported for expanded polypropylene (EPP) and expanded polystyrene (EPS) in the literature (Figure 11A2,A3).…”

“…These properties exceeded those reported for expanded polypropylene (EPP) and expanded polystyrene (EPS) in the literature (Figure 11A2,A3). 53,87–89 Moreover, lightweight, high‐strength, and conductive polystyrene (PS) composite bead foams were successfully produced using microwave foaming and sintering techniques (Figure 11B1,B2). 90 These foams exhibited exceptional comprehensive properties, including a low density of 0.095 g/cm 3 , an ultralow percolation threshold of 0.0014 vol%, and a high specific electromagnetic interference (EMI) shielding effectiveness of 211.5 dB·cm 3 /g at 12.4 GHz, with only 0.046 vol% CNT content (Figure 11B3,B4).…”

“…(A) Antistatic PP foams fabricated by microwave irradiation (A1: morphology of interface, A2: short‐circuit current, and A3: comparison of compressive strength). Reproduced with permission 53 . Copyright 2022, Elsevier.…”

“…As a result, this bead foaming method is only suitable for commodity polymers with low T m and low T g . To date, only a limited number of commodity polymers, such as expandable polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP), have been successfully commercialized 45–53 …”