Advanced Materials Research Vols. 1033-1034

Abstract: A calculation method for predicting compatibility of two polymers on blending is proposed. The method is based on the criterion of polymer solubility in organic solvents; the criterion takes into account the chemical structure of both polymer and solvent, surface forces, and the polymer-solvent intermolecular interaction energy. When two polymers are mixed together, one of them is regarded as a "solvent". The applicability of the method to fully compatible, partially compatible, and absolutely incompatible polymers is analyzed. It is shown that the composition of microphases at microphase separation can be approximately calculated using the dynamic mechanical analysis (DMA).

Abstract: Polystyrene (PS) had wide range of applications in food packaging field. Mechanical recycling of PS was simulated by multiple extrusions to assess the behavior of physical degradation. The molecular weight and the molecular weight distribution of PS with different extrusion cycles were investigated by gel permeation chromatography (GPC). Experimental results show that the differential and cumulative distribution curves of PS shift to smaller values with the number of extrusions cycled increasing. The Mn and Mw of PS decrease. However, Polydispersity index (PDI) increases obviously.

Abstract: According to the reaction principle of polydimethylsiloxanols produced by one-Step synthesis, the mathematical model is fitted by analyzing the result of test. This is a complex system with nonlinear time-Varying coupling characteristics, considering the requirements of dynamic and static performance indicators ,easily controlled features and simple structure, the combine control strategy of conventional PID and Fuzzy PID is used. The results show that the control precision of conversion rate is high and the robustness and adaptive ability of the system are both improved. This lays theoretical foundation to produce the polydimethylsiloxanols continuously in large scale in the future.

Abstract: Nanostructural materials of polymeric Schiff base (PSB) have been selectively synthesized via interfacial polymerization (IP) by modifying the polymerization process. The effects of synthesizing methods, catalyst, the monomer concentration and the reaction time on the morphology of PSB nanostructural materials are investigated. The samples are characterized by TEM, FT-IR, UV-Vis, XRD, thermal analysis, and electrical conductivity measurement techniques. The results show that the PSB nanostructural materials, such as nanofilms and-rods, can be obtained via IP. Na⁺ and NH₄⁺ ions act as shape-regulated agents. Na⁺ ion can control the growth of PSB nuclei along two-dimension to obtain PSB nanofilms and NH₄⁺ is advantage to the growth of PSB nuclei along one-dimension to obtain PSB nanorods. It is also found that the polymer nanocrystals show high thermal stability and the iodine-doped polymer is a semiconductor material.

Abstract: The application of new polymer materials in modern agriculture is considered and discussed in a completely new view in this paper. Combined with modern agricultural characteristics: out of season and large-scale planting, the excellent characteristics of modern polymeric materials are skillfully applied to modern agriculture greenhouse rack, which solves many defects of the traditional greenhouse frame structure material. This paper takes Hainan Province as the area of greenhouse structure research and analyze the shed load in the view of structural analysis, based on which the finite element software ABAQUS for the greenhouse framework structure are analyzed by finite element analysis. The results show that the stress and deformation results can satisfy the requirements of structural strength in the normal load conditions.

Abstract: ATRP is one of the most active fields in polymer science. The feature of ATRP is chain propagation by way of transfer of halide atom with or without the catalysis of transition mental compounds. The termination reaction between radicals is reduced by low concentration of free radicals under the control of the fast transfer. A variety of monomers including styrene, acrylates, methacrylates, and dienes can be used in this technique. ATRP is a simple and inexpensive process for controlled "living" radical polymerization leading to well-defined homopolymers and copolymers. In this paper, the mechanism, initiator, catalyst systems, polymerization mediums and conditions of ATRP are introduced, the prospect of ATRP is also discussed.

Abstract: Nitrile butadiene rubber (NBR) comes into widespread applications due to the excellent performances, but it is susceptible to aging during its storage and usage periods. This paper surveys the external factors that act on the aging process of NBR. The aging of NBR in liquid environment, and non-liquid environment such as thermo-oxidative aging, ozone aging, stress aging and radiation aging, are considered. The emphasis of present works is test of physical and mechanical properties of NBR, and the micro analysis should gain special attention. One direction of future research on NBR aging is the coupling effects of various factors included in this paper.

Abstract: This passage studied the synthetic process of melamine formaldehyde resin foam, analyzed the addition time of modifier of PVA, reaction temperature, PVA quantification and different degree of polymerization PVA. The results of experiments showed that it was better to add the PVA at 50min after the heating start. The temperature was 90-95°C. It showed that there was an obvious distinction of the foam with different degree of polymerization PVA. Decomposition temperature of the foam was 300°C and the residual of mass was about 80%.

Abstract: A core-shell composite polymer was produced by the method of high internal phase emulsion polymerization. The continuous phase of emulsion contained styrene(St), butyl methacrylate(BMA), octamethylcylotetrasiloxane(D4), and azobisisobutyronitrile (AIBN) which worked as an initiator. The block copolymers with St, BMA, D4 units are particularly promising for surface modification and hydrophobicity. The core-shell structure is proved by the use of Transmission electron microscopy (TEM). In addition, the water contact angle increased with the increasing weight ratio of D4. The results show that the concentrated emulsion system has good stability and the water resistance of the polymer has been improved greatly.

Abstract: A novel and facile process called “alternative loop immersion method” formed bioactive and biocompatible Zn-doped calcium silicate coating over the drug-loaded titania nanotube arrays to improve the properties of drug release. The samples were characterized by scanning electronic microscope (SEM), x-ray diffraction (XRD) and fourier transform infrared (FT-IR). The results show that TNTs modified by Zn-doped calcium silicate coating possess improved drug release characteristics with reduced burst release (from 83% to 66%) and prolonged drug release (from 11 days to over 15 days). This approach provides an alternative to tailor the surface of TNTs and offer considerable propects for diverse biomedical applications.