Effect Of Polymer Modification Research Articles

Permeability of polymer-modified kaolinite and fly ash–kaolinite mixtures

With the goal of promoting the treatment and reuse of fly ash (FA), a series of permeability tests were conducted to investigate the hydraulic conductivity (K) of polymer (chitosan, polyethylene oxide (PEO) and xanthan gum)–FA—kaolinite (KA) systems under different confining pressures and overconsolidation ratios (OCRs). The addition of FA increased the K of KA due to changes in particle size and gradation, and the effect is not significant when the FA content is below 30%. PEO and xanthan gum increased the K of KA, with xanthan gum having a more significant effect, while chitosan reduces it. For FA–KA mixtures, chitosan and xanthan gum had negligible impact on the K, whereas PEO increased it by an order of magnitude. In addition, confining pressure restricts the flow channel while increasing the effective contact area between polymers and soil particles. The Koc/Knc of polymer-modified KA rapidly converges at high OCRs, while that of polymer-modified FA–KA converges at low OCRs. This study provides insight into the effects of polymer modification on the hydraulic conductivity of FA–clay mixtures and provides guidance for the application of polymer modification technology in soil improvement.

Evaluation on the Performance of Hydraulic Bitumen Binders under High and Low Temperatures for Pumped Storage Power Station Projects.

The high and low-temperature performance of five hydraulic bitumen binders was evaluated using the dynamic shear rheometer (DSR) test, infrared spectrum test and direct tensile (DT) test. These hydraulic bitumen binders were respectively applied for several pumped storage power stations (PSPS) projects that were constructed or under construction. In order to relate the bitumen performance to the mixture performance, the slope flow test, three-point bending test and thermal stress restrained specimen test were carried out on hydraulic asphalt mixtures. The test results indicated the DSR rheological master curves can well distinguish the difference of each bitumen binder as well as the effect of polymer modification. Phase angle master curves, black diagrams and infrared spectra all indicated that several penetration-grade hydraulic bitumen binders were not virgin bitumen binders but were modified with relatively lower SBS polymer content when compared with traditional SBS-modified bitumen. When selecting the commonly used Karamay SG70 hydraulic bitumen as a reference, the normal SBS-modified bitumen was superior to other bitumen in terms of low- and high-temperature performance. Several slightly SBS-modified bitumen binders did not always show consistent results, which indicated that slightly modified bitumen may not really have the desired performance as expected. Therefore, SBS-modified bitumen will be more promising when dealing with extremely low or high temperatures. Bitumen performance was well compared with the mixture performance by using the bitumen creep, relaxation and tensile failure strain corresponding to the asphalt concrete slope flow, the maximum bending strain and the failure temperature, respectively. Compared with the traditional penetration, softening point and ductility test, it indicated that the DSR rheological test, creep test, direct tensile test and stress relaxation test can be used as more powerful tools for the characterization and optimization of hydraulic bitumen binders.

Rheological properties and microscopic mechanism of rock asphalt composite modified asphalts

In order to improve the low temperature performance of rock asphalt modified asphalt, this work presents a laboratory study to evaluate the rheological properties of rock asphalt composite modified asphalts considering aging effect. The mechanical properties of rock asphalt (RA)/styrene–butadienestyrene (SBS) composite modified asphalt (RA/SBSCMA) and RA/crumb rubber (CR) composite modified asphalt (RA/CRCMA) were assessed based on penetration, softening point and rotational viscosity tests. Experiments, including bending beam rheometer (BBR), dynamic shear rheometer (DSR), multiple stress creep and recovery (MSCR), fluorescent microscope (FM), and Fourier transform infrared spectroscopy (FTIR), were conducted to investigate the rheological properties and microstructure of rock asphalt composite modified asphalts, as well as the effect of polymer modification and aging on asphalts. Results demonstrated that the RA/CRCMA exhibited higher consistency, better deformation resistance and temperature sensitivity than RA/SBSCMA. The performance grade (PG) of RA/CRCMA indicates superior high- and low-temperature performance, of which the RA/CRCMA with 5% rock asphalt and 18% crumb rubber (5R/18C) performed the best. The RTFO and PAV aging reduced the frequency sensitivity, facilitated the internal network structure stability and improved the compatibility of the RA/SBSCMA with 5% rock asphalt and 2% SBS (5R/2S). The 5R/18C presented superior compatibility in different aging states. The MSCR test results showed that the RA/CRCMA exhibits excellent resistance to permanent deformation and superior elasticity and recovery deformation ability. The FM test revealed that grooves and protrusions existed on the surface of RA/CRCMA, and the spheroidal RA particles and the CR particles with irregular linear or mesh structure dispersed in the asphalt phase separately. The FTIR test results proved that the RA/SBSCMA was a primarily physical modification in nature, while the RA/CRCMA was a physical–chemical modification. The CR presented stronger inhibition on the formation of carbonyl and sulfoxide compounds than the SBS resulting in more excellent anti-aging performance of corresponding composite modified asphalt. It is recommended that the optimal percentages of additive materials were 5% for RA and 18% for CR.

Effects of ageing on the damage tolerance of polymer modified bitumens investigated through the LAS test and fluorescence microscopy

ABSTRACT The effects of polymer modification on the durability of Polymer Modified Bitumens (PMBs) still remain relatively unclear due to partial understanding of the combined effects of ageing and loading on damage accumulation. This paper investigates the effects of laboratory ageing on the damage tolerance of cross-linked SBS and EVA modified bitumens measured using the Linear Amplitude Sweep (LAS) test and corroborated with the morphology of the PMBs. The PMBs were prepared with three polymer concentrations (i.e. 2%, 4% and 6%). In general, ageing affects the capacity of bitumens to maintain integrity to damage and reduces their time-temperature susceptibility. The damage tolerance is derived from the combination of the two mechanisms as a function of the bitumen’s strain level. At low strain levels, typical of thick pavements, ageing enhances the damage tolerance. Contrarily, at higher strain levels, it provides the opposite effect. SBS improves the damage tolerance of the base bitumen as a function of polymer concentration and dispersion. However, the polymer chain undergoes oxidative degradation and its effect reduces with ageing. EVA forms a polymer network with a low oxidative susceptibility that contributes, at low strain, to maintaining or improving the damage tolerance with ageing as a function of the polymer concentration.

Low-temperature rheological and morphological characterization of SBS modified bitumen

Polymer modification is widely used to improve the engineering properties of bitumen, the most commonly used polymer modifier being styrene-butadiene-styrene (SBS) block copolymer. Although extensive studies have been performed on polymer modified bitumen (PMB), no reliable data is currently available on the effect of polymer modification on the dynamic rheological properties at low temperatures. In this study, we focus on the rheology of SBS modified bitumen near and below the glass transition temperature (Tg) using the 4-mm DSR technique. In addition, fluorescence microscopy and temperature-modulated differential scanning calorimetry are used to study the phase behavior and interactions in the SBS-bitumen blends. At high SBS concentrations, thermorheological complexity is observed in the investigated temperature range, attributable to the formation of a continuous SBS-rich network structure. In the case of compatible SBS-bitumen blends, a linear correlation is established between the flexural creep stiffness measured by bending beam rheometry (BBR) and the complex shear modulus measured by 4-mm DSR. Deviations from this linear trend are shown to result from the macro-phase separation induced by the poor compatibility of SBS and bitumen.

Effect of polymer addition on air void content of fine grained concretes used in TRCC

Textile Reinforced Cementitious Composite (TRCC) became the most common construction material lately and have excellent properties. TRCC can be employed in the manufacture of thin-walled facade elements, load-bearing integrated formwork, tunnel linings or in the strengthening of existing structures. These composite materials are a combination of matrix and textile materials. There isn\'t much research done about the usage of polymer modified matrices in textile reinforced cementitious composites. In this study, matrix materials named as fine grained concretes (dmax 1.0 mm) were investigated. Air entraining effect of polymer modifiers were analyzed and air void content of fine grained concretes were identified with different methods. Aim of this research is to study the effect of polymer modification on the air content of fine grained concretes and the role of defoamer in controlling it. Polymer modifiers caused excessive air entrainment in all mixtures and defoamer material successfully lowered down the air content in all mixtures. Latex polymer modified mixtures had higher air content than redispersible powder modified ones. Air void analysis test was performed on selected mixtures. Air void parameters were compared with the values taken from air content meter. Close results were obtained with tests and air void analysis test found to be useful and applicable to fine grained concretes. Air void content in polymer modified matrix material used in TRCC found significant because of affecting mechanical and permeability parameters directly.

Characterization of Steel Fiber Reinforced Acrylic Emulsion Polymer Modified Concrete (SFRPMC) through X-Ray Diffraction (XRD) Analysis

The results show the effect of polymer modification on the behavior of Ca (OH)2 in steel fiber reinforced concrete. The polymer modified concrete were prepared using acrylic emulsion polymer at various polymer-cement ratios; they were tested for mechanical strengths, moulded into specimens and cured. The cured specimens were subjected for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. The small specimens that moulded were subjected to X-ray diffraction (XRD). From the test results, it is concluded that formation of Ca (OH)2 in the polymer modified concrete reinforced with steel fiber is reduced possibly because of the absorption of Ca (OH)2 on polymer films formed in the concrete. The extent of reduction in the quantity of Ca (OH)2 depends upon the polymer-cement ratio, polymer type or both. Generally SFRPMC of mix 43 with 2.5% polymer-cement ratio were found to be more effective than other SFRPMC with 1.0% and 4.0% acrylic emulsion polymer in reducing the quantity of Ca (OH)2 in SFRPMC. The cement modifiers did not cause any detrimental effect on the degree of hydration as in SFRPMC therefore, does not provide a proper means for predicting their degree of hydration.

Processing fragile matter: effect of polymer graft modification on the mechanical properties and processibility of (nano-) particulate solids.

The effect of polymer modification on the deformation characteristics and processibility of particle assembly structures is analyzed as a function of particle size and degree of polymerization of surface-tethered chains. A pronounced increase of the fracture toughness (by approximately one order of magnitude) is observed as the degree of polymerization exceeds a threshold value that increases with particle size. The threshold value is interpreted as being related to the transition of tethered chains from stretched-to-relaxed conformation (and the associated entanglement of tethered chains) and agrees with predictions from scaling theory. The increase in toughness is reduced with increasing particle size - this effect is rationalized as a consequence of the decrease of entanglement density with increasing dimension of interstitial (void) space in particle array structures. The increased fracture toughness of particle brush materials (with sufficient degree of polymerization of tethered chains) enables the fabrication of ordered colloidal films and even complex 3D shapes by scalable polymer processing techniques, such as spin coating and micromolding. The results, therefore, suggest new opportunities for the processing of colloidal material systems that could find application in the economical fabrication of functional components or systems compromised of colloidal materials.

Cell-derived vesicles modified with pH-sensitive polymers for intracellular delivery of autologous antigen

Event Abstract Back to Event Cell-derived vesicles modified with pH-sensitive polymers for intracellular delivery of autologous antigen Eiji Yuba1*, Takanori Sakano1*, Takumi Kato1*, Takuma Urasaki1, Atsushi Harada1* and Kenji Kono1* 1 Osaka Prefecture University, Graduate School of Engineering, Japan Introduction: Efficient antigen carriers to dendritic cells (DCs) are needed for establishment of cancer immunotherapy. We previously reported cytoplasmic delivery using liposomes modified with pH-sensitive polymers, such as carboxylated poly(glycidol)s or dextrans[1],[2]. These liposomes delivered model antigen, ovalbumin (OVA), into cytosol of DCs and induced OVA-specific antitumor immunity. However, tumor antigen of each patient is different because of the difference of genetic mutation in each patient. Therefore, cancer cell-derived vesicles, such as plasma membrane vesicles (PMVs) or exosomes, were used as resources of tumor antigen and modified with pH-sensitive polymers (Figure 1). In this study, the effects of polymer modification on antigen delivery performance of cell-derived vesicles were examined. Materials and Methods: PMVs or exosomes were extracted from cancer cells, such as murine T lymphoma E.G7-OVA cells or their culture medium using repeated centrifugation, respectively. They were modified with 3-methylglutarylated or 2-carboxycyclohexane-1-carboxylated poly(glycidol)s (MGluHPG or CHexHPG, respectively) and characterized using DLS, AFM and TEM. pH-sensitivity of vesicles were measured by change in optical density or fusion assay based on FRET. Fluorescence-labeled vesicles were added to DC2.4 cells, a murine dendritic cell line, and then, cellular association and intracellular distribution of vesicles were evaluated by FCM and CLSM. These vesicles or vesicle-treated DCs were administered to tumor-bearing mice and their antitumor effects were investigated. Results and Discussion: Polymer-modified PMVs showed around 300 nm of diameters, while PMV formed micrometer-sized aggregates, indicating that polymer-modification increased the colloidal stability of PMVs (Figure 2A). Exosomes showed almost same size distribution irrespective of polymer modification. Polymer-modified vesicles showed increase of optical density and induced fusion with liposomes at acidic pH, which suggests that polymers became hydrophobic at acidic pH and induced fusion with other membranes. Polymer modification increased cellular association of PMVs and exosomes to DCs, indicating that carboxyl groups in polymers modified onto vesicles were recognized by scavenger receptors of DCs. Polymer-modified vesicles delivered their contents into cytosol of DCs (Figure 2B). Antitumor effects induced by administration of these vesicles or vesicle-treated DCs were promoted by polymer-modification probably because of their efficient delivery of cancer cell derived-antigen into cytosol of DCs. Conclusion: In this study, cancer cell-derived vesicles modified with pH-sensitive polymers were developed. Polymer modification to PMVs or exosomes enhanced their cellular association, intracellular delivery performance and antitumor effects. Therefore, cancer cell-derived vesicles modified with pH-sensitive polymers are promising as delivery carriers of autologous cancer antigen for establishment of cancer immunotherapy. This work was supported by grant from The Naito Foundation.

The Influence of Surface Modification on the Photoluminescence of CdTe Quantum Dots: Realization of Bio-Imaging via Cost-Effective Polymer.

To impart biocompatibility, stability, and specificity to quantum dots (QDs)-and to reduce their toxicity-it is essential to carry out surface modification. However, most surface-modification processes are costly, complicated, and time-consuming. In addition, the modified QDs often have a large size, which leads to easy aggregation in biological environments, making it difficult to excrete them from in vivo systems. To solve these problems, three kinds of conventional polymers, namely, polyvinyl alcohol (PVA, neutral), sodium polystyrene sulfonate (PSS, negative charged), and poly(diallyl dimethyl ammonium chloride) (PDDA, positive charged) were selected to modify the surface of QDs at low cost via a simple process in which the size of the QDs was kept small after modification. The effect of polymer modification on the photoluminescence (PL) properties of the QDs was systematically investigated. High quantum yields (QYs) of 65 % were reached, which is important for the realization of bio-imaging. Then, the cytotoxicity of CdTe QD-polymer composites was systematically investigated via MTT assay using the Cal27 and HeLa cell lines, especially for high concentrations of QD-polymer composites in vitro. The experimental results showed that the cytotoxicity decreased in the order CdTe-PDDA>CdTe>CdTe-PSS>CdTe-PVA, indicating that PSS and PVA can reduce the toxicity of the QDs. An obvious cytotoxicity of CdTe-PVA and CdTe-PSS was present until 120 h for the Cal27 cell line and until 168 h for the HeLa cell line. At last, the Cal27 cell line was selected to realize bio-imaging using CdTe-PSS and CdTe-PVA composites with different emission colors under one excitation wavelength.

Morphological analysis of bitumen phases using atomic force microscopy

The structure of asphalt is generally considered to be a colloidal system where high molecular weight components (asphaltenes) are dissolved into an oily lower molecular weight matrix (maltenes). To better understand the morphology of the asphalt binder, the different components associated with this material were analysed under topographic and phase detection atomic force microscopy, and optical microscopy, for a specific asphalt binder type. The analysed asphalt binder was identified as a multi-phase type asphalt binder that exhibits four distinct phases: the para-phase which serves as a dispersing medium to the catana-phase (‘bee’ structure), the per-phase (area surrounding the catana-phase), as well as the sal-phase (smaller dispersed phase). A component analysis of the asphalt binder yielded that a form of the per-phase and catana-phase can be associated with the aromatics. The sal-phase was observed on the asphaltenes and resins. Furthermore, an additional filament-type structure was also identified on the resins. The analysis was also complemented by combining individual Saturates-Aromatics-Resins-Asfaltenes (SARA) components of the asphalt binder to observe the evolution of the different structures and morphology present in the asphalt binder. Enriched asphalt binder with 50% of each of the SARA fraction at a time was also analysed. It was determined that the size and shape of the different structures are a function of the combination of the different asphalt components. The effect of polymer modification and ageing due to temperature was briefly analysed. The results were also correlated with detailed infrared spectroscopy (FTIR) analysis of the different asphalt components.

Influence of polymer modification on asphalt binder dynamic and steady flow viscosities

Asphalt pavement performance such as rutting, crack initiation and propagation as well as fatigue behaviour are substantially affected by the rheological properties of the bitumen. In this sense, the use of polymer modification in road paving applications has been growing rapidly over the last decade as it allows significant enhancements in bitumen properties with consequent improvement in road service life. In fact, the use of polymer modified bitumens (PMBs) leads to pavements characterized by higher resistance to rutting and thermal cracking and lower fatigue damage, stripping and thermal susceptibility. This paper presents a laboratory investigation concerning the effect of polymer modification on the flow behaviour of bitumens. Two different polymers, an elastomer and a plastomer, were used as bitumen modifying agents at three different percentages (2%, 4% and 6% by bitumen weight). Oscillatory mechanical analysis as well as viscosity measurements under steady state conditions were performed taking into account different testing parameters such as temperature, loading frequency and shear rate. The results confirm that the rheological properties of PMBs are strongly influenced by polymer nature and polymer content. The bitumen viscosity on the dynamic domain was combined with that in the steady-state domain, confirming the applicability of the Cox–Merz relationship for the plain bitumen and the PMBs with low polymer content. Finally, the Cross and the Carreau models were found to be suitable to fit the steady state and the dynamic results in order to determine the viscosity function of the investigated bitumens.

Effects of polymer modification on the permeability of cement mortars under different curing conditions: A correlational study that includes pore distributions, water absorption and compressive strength

This paper, based on laboratory programs, evaluated the oxygen permeability over different stages of aging for three commercial polymer-modified mortars; styrene–butadiene rubber, polyacrylic esters and vinyl acetate–ethylene as well as unmodified conventional mortar exposed to different curing conditions. The relationship of its permeability with pore size distributions, water absorption and compressive strength has also been investigated. The results indicated that the presence of polymer latex in the mortars greatly enhanced the pore structure of the paste and resulted in increasing the waterproofness and hence, impermeability of the polymer cements system. Moreover, the best curing conditions of the mixes were also highlighted by the study.

The effect of polymer modification on hot mix asphalt fracture at tensile loading conditions

A laboratory investigation was conducted to evaluate the effect of both cross-linked and linear styrene–butadiene–styrene (SBS) modifiers on the cracking resistance of hot mix asphalt (HMA) mixtures. Five types of asphalt mixtures composed by the same aggregate gradation but different asphalt binders were produced in the laboratory. The cracking performances of the mixtures were evaluated using a viscoelastic fracture mechanics-based model entitled ‘HMA Fracture Mechanics’. Crack localisation and crack growth were investigated performing the indirect tensile test and the semi-circular bending test. A digital image correlation system capable of providing full-field strain maps was applied. The results show the benefit of SBS modifiers to the mixture's cracking resistance in terms of reduced rate of damage accumulation and increased tensile limits to failure. Finally, significant damage and first fracture have shown to be strongly more localised in modified specimens than in the unmodified one.

Effects of polymer modification on the fuel resistance of asphalt binders

Fuel resistance is an important characteristic of asphalt binders, especially when used in airport fields and filling stations. However, the relevant standards are presently lacking and the scientific literature on the development of suited formulations is sparse. In this paper, a simple procedure to assess the fuel resistance of asphalts (considered in a dynamic sense) is proposed. A number of polymer modified asphalts (PMAs), prepared from two bases and 4 or 6 wt% of several polymers, have been analyzed with this procedure and the relationships between fuel resistance and morphology of the PMAs, the chemical structure of the polymers and the composition of the asphalt bases have been investigated.

Effects of Polymer Modification on Properties and Microstructure of Model Asphalt Systems

Physical properties and microstructures of computational model asphalts were investigated using molecular dynamics simulations in an all-atom framework. A new model asphalt is proposed that is targeted toward core asphalt AAA-1 of the Strategic Highway Research Program (SHRP) based on elemental composition and speciation. Individual compounds were chosen from the literature to represent asphaltene, polar aromatic, naphthene aromatic, and saturate, with interactions ranked using Hansen solubility parameters. The density and thermal expansion coefficient agreed better with experimental data than had predictions using earlier model asphalts. In addition, one polystyrene molecule with 50 repeat units was added into a ternary model asphalt from earlier work and the new six-component AAA-1 model system to analyze polymer modification effects. The expansion coefficient, isothermal compressibility, and their temperature dependence decreased with one polymer chain present, while density increased. Self-diffusion coefficients of each component in both model asphalts decreased upon including the polymer. To assess microstructure, radial distribution functions g(r) of asphaltene and simplified resin molecules were calculated at different temperatures. Asphaltene results changed with temperature and upon including one polymer; artifacts of initial configuration were found at lower temperatures. Radial distribution functions for pairs of resin-like molecules (dimethylnaphthalene, benzoquinoline, and ethylbenzothiophene) and for asphaltene−resin pairs retained similar shapes and first peak positions at different temperatures and when including the polymer. Results for unlike molecules indicated a depletion of resin [g(r) <1] immediately surrounding an asphaltene molecule, rather than the enrichment expected from standard “colloid model” descriptions, in which resins solubilize asphaltenes. Intermolecular orientations between closest asphaltene pairs in original and polymer modified systems were strongly peaked toward parallel packing and remained similar at several high temperatures. Orientations between asphaltenes and resins and among resins were weighted toward parallel, compared to random packing, both with and without a polymer and over a range of temperatures.

Influence of polymer modification on low temperature behaviour of bituminous binders and mixtures

Effects of polymer modification on low-temperature properties of bituminous binders and mixtures were studied. Three bitumens were blended with 6% SBS, SEBS, EVA or EBA. Dense graded asphalt mixtures were prepared using a gyratory compactor. The low-temperature properties of the binders were characterised using dynamic shear rheometer and bending beam rheometer, and the low-temperature cracking of the mixtures evaluated by tensile stress restrained specimen test. The results indicated that low-temperature parameters were greatly dependent on the base bitumen, and in most cases, polymer modification did not show significant benefits as compared to the corresponding base bitumen. The mixture cracking temperature was found to correlate with the limiting temperatures (in bending beam rheometer) of the binders, weakly with Fraass breaking point, but not with parameters obtained using dynamic shear rheometer. Upon isothermal storage at low temperatures, the bitumens displayed physical hardening, and effect of polymer modification was small. However, physical hardening as measured by TSRST (tensile stress restrained specimen test) was not observed for the mixtures studied.

Copolymerization and photostabilization of methylmethacrylate with 1,8-naphthalimide fluorescent brighteners

The copolymerization of methylmethacrylate (MMA) with 1,8-naphthalimide fluorescent brighteners (fluorophores) yielding transparent blue fluorescent side-group copolymers has been investigated. It has been found that more than 0.92% of the fluorophores are chemically bonded to the polymer chain. Changes occurring in the chromophoric systems of the fluorophores during copolymerization have not been detected. The effect of polymer modification has been proved by an appropriate spectrophotometric method. The influence of the studied monomeric 1,8-naphthalimide fluorescent brighteners upon the photostability of the structurally bleached polymethylmethacrylate has been determined.

Laboratory study on the low temperature physical hardening of conventional and polymer modified bitumens

Physical hardening is a reversible process that may influence the long-term performance of a material. In this paper, physical hardening of five unmodified and 35 polymer modified bitumens was studied using a bending beam rheometer (BBR). The modified binders were prepared by mixing 3, 6 or 9% styrene–butadiene–styrene (SBS), styrene–ethylene–butylene–styrene (SEBS), ethylene vinyl acetate (EVA) or ethylene butyl acrylate (EBA) polymers with different base bitumens. The binders were isothermally stored at low temperatures (−15, −25 and −35°C) for different times ranging from 0.5 to 32 h. The results indicated that physical hardening significantly influenced the creep response of the binders, and the hardening index and horizontal shift factor were strong functions of isothermal storage temperature. Unlike the shift factor, the hardening index did not always increase with decreasing storage temperature. At a given storage temperature, a statistical correlation was observed between the two parameters. It was also shown that degree and kinetics of physical hardening were dependent on the base bitumens, and in most cases, the effect of polymer modification was insignificant.

The effect of polymer modification on microwave digestion efficiency, thermal stability and plasma etching resistance for the photoresist

The UV/VIS spectrometric and gravimetric methods were successfully implemented to evaluate the open-focused microwave digestion efficiency for a photoresist sample after modification with poly(4-hydroxystyrene) polymer. The polymer modification can slightly degrade the digestion efficiency for the photoresist. By following the established microwave digestion method and inductively coupled plasma mass spectrometry determination, the detection limits obtained for multi-elements were in the ng ml−1 and sub-ng ml−1 levels. Except for calcium, the spike recoveries of the metals were in the range 88–128% for the modified sample. The analytical results were found to be in reasonably good agreement with the literature values. The mass losses of the modified photoresists appeared at three major decomposition temperatures (138–142, 344–357 and 471–509 °C), irrespective of the amounts of modification. The modification can enhance the thermal stability, viscosity and plasma etching resistance for the photoresist. Our results demonstrated that the polymer structure of the photoresist is still similar regardless of the modification.