Synthesis And Application Of Typical Olefin-maleic Anhydride Alternating Copolymer Derivatives

The C5-C9 fractions obtained from petroleum after fluid catalytic cracking（FCC）or deep catalytic cracking（DCC）contain large quantities of mixed olefins that are difficult to separate.It is challenging to achieve the effective utilization of them due to their low polymerization activity,complex composition and the presence of sulphur-containing compounds.Currently,the widely adopted treatment is to use C5-C9 fractions as fuel after catalytic hydrogenation or catalytic etherification,which suffers from high cost and complicated process.Besides,the added value of the obtained products is low and the potential application value of olefin resources is not exploited sufficiently.To address the above problems,in the present thesis,four types of olefin-maleic anhydride copolymer precursors were prepared based on the self-stabilized precipitation polymerization（2SP）developed by our group,using three typical mixed hydrocarbon fractions（namely C8 mixtures,light naphtha and unetherified gasoline）and styrene monomer.On this basis,a series of modification methods,such as sulfonation,esterification,amidation and imidation,were adopted to synthesize the derivatives of olefinic-maleic anhydride alternating copolymer with different structures and functions.Subsequently,the derivatives were used as water-reducing agent,coal-water slurry dispersant,scale inhibitor,polyelectrolyte complexes,and phase change materials.The relationship between the structural parameters of the copolymer derivatives and their application performance was investigated systematically.The main contents are as follows:1.Polycarboxylate superplasticizers（PCEs）are one of the most widely used cement additives due to their low dosage and high functionality.In this study,small-sized styrene-maleic anhydride alternating copolymer（PSM）particles with different molecular weights were first prepared by 2SP polymerization using styrene as a model monomer.Then,based on the excellent gas permeability of PSM particles,sulfonated PSM（SPSM）with controllable sulfonation degree were prepared by a facile,efficient and solvent-free gas-solid heterogeneous sulfonation reaction（GSR）with SO₃.The effects of SO₃concentration,temperature and sulfonation time on the sulfonation efficiency and homogeneity of the sulfonation reaction were investigated.Subsequently,comb-type mPEG-grafted SPSM（SPSM-g-mPEG）with controllable side chain density and chain length were prepared by intramolecular catalytic esterification reaction accelerated by the high catalytic activity of-SO₃H and used as PCEs.The effects of structural parameters such as mPEG grafting density,side chain molecular weight and sulfonation degree of SPSM-g-mPEG on its dispersing and viscosity-reducing capacity were investigated in detail using the fluidity of cement paste over time as a criterion.By optimizing the polymer structure,it was found that SPSM-g-mPEG with low backbone Mn,high sulfonation degree and mPEG molecular weight ranging between 2000 and 4000 can improve the fluidity of cement pastes over time significantly,with 2 h fluidity being as high as 312 mm（S88%-P2500-G2000-1/2）and 322 mm（S88%-P2500-G4000-1/2）,respectively.When 0.3 wt%of S88%-P2500-G4000-1/2 was added,the 28 d compressive strength of cement stone increased by 16.7%compared to the reference,which was attributed to its excellent dispersing ability to cement clinker particles.2.Dispersant is an indispensable component for the preparation of clean fuel coal-water slurry（CWS）,and its dispersing and viscosity-reducing ability mainly depends on the distribution of hydrophilic and hydrophobic groups along polymer chain.In this study,SPSM with controllable molecular weight and sulfonation degree were synthesized by 2SP polymerization and GSR reaction using styrene as a model monomer,and amphiphilic NSPSM CWS dispersant was prepared after neutralization.The effects of polymer chain length and the distribution of hydrophilic and hydrophobic groups on the performance of the dispersant were studied in detail using the maximum slurry concentration and water separation rate of coal-water slurry as the main criterion.The interaction mechanism between NSPSM molecules and coal particles was further investigated by determining the adsorption amount,zeta potential,surface tension and cross section morphology.When the molecular weight was6200 and the degree of sulfonation was 117%,the dispersing and viscosity-reducing effect of NSPSM was the best,and the maximum slurry concentration and water separation rate could reach 66.5%and 2.0%,respectively,which were better than the corresponding values of commercially available NSF CWS dispersant.This method was subsequently extended to the C8 system and NSPC8M dispersant was prepared successfully.3.Olefin-maleic anhydride copolymer hydrolysates are rich in carboxylate ions,which have great potential as scale inhibitors.In this work,NSPSM scale inhibitors with high calcium ion resistance with controllable molecular weight and sulfonation degree were prepared using 2SP and GSR.The effects of molecular chain length and sulfonation degree of NSPSM on the scale inhibition performance were investigated using the inhibition efficiency and crystalline morphology of Ca CO₃ scale as the main evaluation standards.The results showed that the NSPSM scale inhibitor had an obvious threshold effect,and the scale inhibition effect of NPSM2200-49%S was the best,with the inhibition efficiency reaching 71.6%at the concentration of 80 mg/L.In addition,NSPSM scale inhibitor can change the crystallization behavior of Ca CO₃,which can not only reduce the particle size and densification of Ca CO₃ scale（easy to clean up by physical descaling method）,but also enables the formation of highly ordered dumbbell-shaped or spherical Ca CO₃ crystals by adjusting the concentration of NSPSM.Compared with carboxylate ions,sulfonate ions have higher stability,so the sulfonation treatment can improve the compatibility of NSPSM scale inhibitors for high hardness water significantly.4.Polyelectrolyte complexes（PECs）are polyelectrolyte aggregates driven by electrostatically induced self-assembly,which are widely used in flocculation,homogeneous membrane preparation,drug delivery,and so on.Herein,based on the unetherified gasoline-maleic anhydride alternating copolymers（PUGM）obtained by 2SP polymerization,the polycationic PUGMQ and comb-type polyanionic PUGMS-g-mPEG with controllable side chain densities and chain lengths were prepared by amidation-imidization-quaternization cascade reactions and esterification reaction,respectively.Using the two types of polyions as raw materials,a series of unetherified gasoline-based PECs microspheres with different structures and compositions were prepared by electrostatic attraction-driven self-assembly.The effects of the polyanion chain structure on the stability of the PECs assemblies were evaluated by measuring the mean particle size,particle size distribution and mean zeta potential of the microspheres.The introduced hydrophilic mPEG side chains were able to form a protective physical hydration membrane that could provide steric hindrance stabilization,thus ensuring that the PECs system maintained stable over a wide range of p H（4～11）and ionic strength（0～40 mg/L）.The results of flocculation experiments showed that PECs exhibited higher flocculation efficiency at low concentrations compared to PUGMQ.5.The development and application of efficient cement water-reducing agents are crucial for the improvement of concrete batching and construction levels.In this part,light naphtha-maleic anhydride alternating copolymer（PLNM）was prepared by 2SP polymerization using mixed olefin in light naphtha and MAH as copolymerization monomers.A series of slow-setting NTPLNM cement water-reducing agents with controllable sulfonate ion density were prepared after neutralization by introducing sodium taurate side group via amidation reaction.The effect of amidation degree of NTPLNM on its dispersing and viscosity-reducing effect was investigated using the fluidity of cement paste over time as a criterion.The influence of the amidation degree of NTPLNM on its retarding effect was investigated by characterizing the heat of hydration and setting time.Finally,the working mechanism of NTPLNM molecules was elucidated by the characterization of adsorption capability,zeta potential and XRD.The introduction of sodium taurate side group can improve the tolerance of NTPLNM to Ca²⁺significantly,thus enhancing its adsorption and dispersing ability,and reaching a fluidity of cement paste up to 250 mm at2 h.In addition,retarding efficiency of NTPLNM could be adjusted flexibly by altering amidation degree.6.Fatty alcohol-based phase change materials have the advantage of high latent heat of fusion,which has a wide application prospect in the fields such as battery thermal management,wall insulation and so on.In this work,light naphtha-based polymer PLNM was prepared based on 2SP polymerization.A series of fatty alcohol-modified PLNM（FMPLNM）with controllable fatty alcohol side chain density and molecular weight were prepared through the esterification reaction with dodecanol,hexadecanol,octadecanol and eicosanol.PEA-cl-FMPLNM shape-stabilized phase change energy storage materials（SSPCMs）materials with excellent shape stability,high encapsulation efficiency（90.4%）and controllable phase transition temperature（24.5～64.1°C）were prepared by introducing poly（ether amine）D230 as crosslinking components to construct three-dimensional chemical crosslinking networks in situ.The long alkyl side chains improved the compatibility of FMPLNM with fatty alcohols significantly,while the large amount of residual anhydride groups in FMPLNM provided abundant reactive active sites for the construction of cross-linking networks.The results of thermal cycling experiments show that the PEA-cl-FMPLNM materials have good structural stability and energy storage stability.In addition,the SSPSMs material can be endowed with thermal buffering capacity in multiple temperature intervals by adjusting the carbon number of the fatty alcohols.