Graphene has exceptionally high surface area, mechanical properties, electrical conductivity, thermal conductivity, and gas-barrier performance, thus it is considered as an ideal multifunctional filler for rubbers. However, harnessing these properties in rubber nanocomposites requires us to carefully tailor the dispersion state of graphene, the vulcanization kinetics, the interfacial interaction and so on. This review summarized our recent works on how to disperse graphene homogeneously in rubber matrix, what influence of graphene or graphene oxide on the vulcanization behavior of the rubber nanocomposites, how to design a compact filler network in the rubber matrix, and how to engineer a strong interfacial interaction between graphene and rubber. These fundamental researches give us some thumb rules to develop graphene/rubber nanocomposites with significantly improved mechanical properties, gas-barrier performance, thermal stability, electric conductivity, antioxidation ability as well as some functionalities.

A large amount of non-infected plastic wastes are being generated at the healthcare facilities all over the world. However, only a small fraction is recycled. Conventionally, the used plastics are either disposed in landfills or inadequately incinerated. These practices impart an adverse effect on our environment. Plastics are indispensable part of the medical sector owing to their high versatility. The outbreak of Covid-19 clearly showed the growing demand for single use plastics. Hence, completely avoiding plastics can be challenging at this point of time. Recycling of plastics is undoubtedly a solution to solve the crisis of plastic pollution. Medical plastic recycling is limited mainly due to difficulties involved in sorting or cleaning. Recycling medical plastic wastes is possible only through proper coordination between healthcare sector and recycling industries. New recycling technologies are to be adopted in a sustainable manner. Moreover, the plastics used in medical applications should be designed such that recycling is possible. This review highlights the downside of medical wastes and discusses the recycling potential of commonly used medical plastics.

Azidoethyl-2-bromo-2-methylpropanoate (AEBMP) has been synthesized from 2-azidoethanol and 2-bromo-2-methylpropionyl bromide under nitrogen atmosphere. The azido end-functional polystyrene (PS-N₃) has been synthesized by Atom Transfer Radical Polymerization (ATRP) technique using AEBMP initiator and styrene in conjugation with Cu(1)Br-bipyridine catalyst at 100°C. The polymerization was performed at three different periods of time, and it was found that both yield and number average molecular weight were increased linearly with increasing reaction time. Thermogravimetric analysis showed that the polystyrene is stable up to 300°C. The molecular weight of the polystyrene was determined using Gel Permeation Chromatography (GPC), and structures of the initiator AEBMP and polystyrene (PS-N₃) were characterized by ¹H NMR and FT-IR spectroscopy.

Post-consumer plastic waste has reached levels that are dangerous for the environment and for human health, and its management now represents a big challenge. Plastic biodegradation and biorecycling emerges as an addition to the conventional plastic waste recycling methods. This review describes recent studies on enzyme-catalysed synthetic polymers biorecycling and biodegradation. The emphasize lies on the most successful cases as that of enzyme-catalysed depolymerisation of polyethylene terephthalate, using a specially engineered enzyme PET depolymerase, that has recently been developed into industrial technologies as well as on other recent promising discoveries of enzymes that are potentially capable of complete and controlled plastic degradation in mild conditions. The review also discusses polymer qualities that are causing diminished plastic biodegradation, and the protein engineering methods and tools to increase enzyme selectivity, activity and thermostability. Many fields of expertise have been used in the described studies, such as polymer chemistry, microbiology, mutagenesis, protein and process engineering. Applying this innovative interdisciplinary knowledge offers new perspectives for the environmental waste management and leads to a sustainable circular economy.

The excellent mechanical properties and fatigue-resistance of natural rubber (NR) are closely related to the strain-induced crystallization (SIC) capability of NR, which is originated from the unique network structure of NR. The synthetic counterpart of NR, cis-1,4-polyisoprene (IR) generally possesses inferior mechanical performance due to insufficient SIC capability. In this contribution, amino-functionalized carbon nanodots (CDs) were introduced as high-functionality cross-linkers into sulfur-cured sulfonated IR, aiming to improve the SIC capability of IR. The amino groups on CD surfaces are connected with the sulfonic acid groups on the IR backbones to form ionic bonds, and a covalent crosslinking is concurrently obtained by using sulfur vulcanization, thereby a dually crosslinked IR network is resulted. When the rubber is deformed, the ionic bond breaks preferentially prior to the rupture of covalent bond, leading to efficient energy dissipation. The preferential rupture of the ionic bonds also promotes the orientation process of IR chains and hence SIC capability, as evidenced by lowered onset strain for crystallization and increased crystallinity. The promoted SIC leads to remarkably improved tensile properties.

Modern microelectronics devices urgently request low dielectric constant materials with commendable mechanical properties. Novel fluorinated poly(aryl ether)s (FPPEs) were prepared by traditional polycondensation of 4-(4-Hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), Bisphenol AF (BAF) and Decafluorobiphenyl (DFB) to study bulky phthalazinone effects on mechanical and dielectric behavior of polymers. After the introduction of phthalazinone moieties, FPPEs showed excellent solubility to readily solve in many organic solvents like NMP, DMAc, CHCl₃, and THF. Simultaneously, they exhibited relatively high glass transition temperatures (T_gs) from 180 °C to 294 °C, increasing with the content of phthalazinone groups. The FPPEs still possessed excellent thermal stability with decomposition temperature up to 514 °C and char yield at 800 °C as high as 56% under nitrogen atmosphere. FPPE films showed good mechanical strength with tensile stress higher than 68MPa and modulus surpassing 10.8MPa, also increasing with phthalazinone concentration. The dielectric property of FPPEs was investigated with impedance analyzer. FPPE8020 and FPPE 6040 showed dielectric constant from 3.10-3.30 and dielectric loss of 0.005-0.008 under a large frequency range of 0.02-60GHz. The phthalazinone moieties mainly contributed to the decrease of dielectric constant. The results evidently suggest FPPEs as commendable candidate for those high-tech electronic applications.