Significance Plastics, characterized by their excellent overall properties, are widely used in aerospace, transportation, new energy, electronics and electrical engineering, construction, agriculture, and medical care. They serve as essential foundational materials as well as advanced engineering materials. China's plastic product output reached 79.2 million tons in 2025, ranking first globally. Plastics require processing before they are formed into final products. Due to the covalent bonds, multilevel structures, viscoelasticity, and soft matter characteristics of polymeric materials, the final structure and properties of plastic products depend much more significantly on processing conditions than those of other materials. Plastic processing is not merely a shaping technology; rather, it represents a scientific discipline dedicated to designing and achieving the desired structures and properties of polymeric materials. With the rapid advancement of modern science, technology, and the national economy, advanced plastic manufacturing and processing, as a critical component of China's manufacturing industry, face new scientific frontiers and major national demands. These challenges include the high-performance and functional upgrading of plastic products to meet the requirements of high-end manufacturing, the high-value and efficient recycling of waste plastics to reduce environmental pollution and raise resource recycling, the development of non-petroleum-based plastics to ensure raw material security, the efficient utilization of natural biomass to optimize resource utilization, and the development of halogen-free flame-retardant plastics to enhance fire safety. Addressing these challenges requires the urgent development of new theories, technologies, and equipment for advanced plastic manufacturing and processing. Progress For decades, the team led by Academician Wang Qi at Sichuan University conducted systematic and in-depth research that addressed academic frontiers and key national economic demands in plastic processing, with a focus on high performance, multifunctionality, lightweight design, precision, and ecological sustainability. The team creatively solved several world-class challenges in the field of plastic processing: Solid-state mechanochemical processing—Based on the principles of polymer mechanochemistry, a novel solid-state shear milling (S3M) system with a unique three-dimensional shear structure was invented, enabling room-temperature ultrafine grinding of polymers, uniform nanofiller dispersion, and partial de-crosslinking of waste cross-linked plastics. In addition, a series of novel technologies for the solid-state mechanochemical preparation and processing of polymeric materials was established and successfully applied in engineering. 1) More than 20 types of polymer-based micro/nano functional composites were prepared on a large scale, including PA11/BaTiO3 (piezoelectric voltage constant 8 times higher than neat PA11), PA12/CNTs, and POM/MoS2. 2) High-quality recycling of blended and cross-linked waste plastics was achieved. Representative examples included the high-value utilization of aluminum-plastic packaging, cross-linked polyethylene (XLPE) cables, and decommissioned wind turbine blades, which were successfully reprocessed into high-performance recycled products such as polyethylene geomembranes and corrugated pipes. 3) The large-scale, high-value solid-state utilization of natural biomass materials, such as shells and cellulose, was achieved, providing an important pathway for addressing resource scarcity. 3D printing of polymer materials—A series of polymer-based micro/nano functional composites suitable for selective laser sintering (SLS) and fused deposition modeling (FDM) was successfully prepared. A liquid-assisted spheroidization technique and a plasma-assisted solid-state mechanochemical spheroidization method were developed for SLS powders. Numerous polymer components with complex geometries and functional characteristics, such as piezoelectric devices, flexible sensors, and bone tissue engineering scaffolds, were successfully fabricated by optimizing the 3D printing process. Micro-injection molding of polymer materials‒The Sichuan University-University of Bradford International Polymer Micro-processing Center was established and equipped with a range of advanced micro-processing equipment for polymeric materials. High-performance, multifunctional polymer-based micro/nano composites suitable for micro-processing were prepared on a large scale using methods such as organic/inorganic hybridization, solid-state shear milling, melt blending, and nanocomposite compounding. A series of advanced molds with replaceable cores, vacuum systems, and dual-temperature control systems was designed. Micro-gears (as small as 0.1 modulus, 2.2 mg), micro-bone screws, and high-performance PVDF-based piezoelectric micro-sensors were produced, achieving a sensitivity of 85 mV/kPa. Rotation extrusion of plastic pipes—The team created axially deviated reinforced structures within the pipes by introducing a rotating flow field during extrusion. This approach increased the hoop strength and crack resistance by more than 70%, producing PE100 pipes with the highest-pressure rating globally (14.9 MPa at 25 ℃ and 6.6 MPa at 80 ℃). A novel rotation extrusion rheometer capable of nine different flow modes and online monitoring of temperature, pressure, and flow rate was also invented. In addition, rotation-extruded polypropylene medical microcatheters and PE/carbon fiber conductive microtubes were prepared. Advanced foaming of plastics—Innovative equipment was developed, including a high-temperature twin-screw extruder capable of operating up to 450 ℃ for supercritical CO2 foaming and a microwave selective heating system for bead fusion. Polyimide bead foams with a uniform cellular structure and a compressive strength of 4.14 MPa were produced using co-foaming agents (scCO2 and ethanol). Microwave-assisted fusion of carbon nanotube-coated PET beads enabled the production of lightweight, high-strength foams. Conductive PEI/CNT bead foams achieved an electrical conductivity of 20.7 S/m and excellent electromagnetic shielding performance. Thermoplastic processing of poly(vinyl alcohol) (PVA)—The team established a thermoplastic processing window above 120 ℃, solving the long-standing problem of PVA thermal degradation near its melting point by disrupting the hydrogen-bond network using molecular complex agents. High-strength PVA fibers with a tensile strength of 1.9 GPa and a modulus of 39.5 GPa were produced through melt spinning. Blown PVA films and biaxially stretched films achieved tensile strengths of 140.6/146.4 MPa (MD/TD) and a puncture strength of 357.9 N/mm. PVA pipes exhibited a gasoline permeability as low as 0.97 g·mm/(m2·d). Self-lubricating PVA microcatheters with antimicrobial properties and PVA foams for cold-chain applications with a latent heat of 309.6 J/g were also developed. A supramolecular composite method was utilized to synthesize modified melamine cyanurate, reducing water consumption by 80% and reaction time by 75%, while enabling industrial-scale production (10 000 t/a). Reactive extrusion was employed to synthesize high-viscosity flame retardants in situ within the polymer matrix. An interfacial flame-retardancy strategy was proposed to concentrate low-content flame retardants at the glass fiber/polymer interface. This strategy reduced the horizontal burning rate of glass fiber-reinforced nylon 6 by 52% and achieved a UL94 V‒0 rating while maintaining the mechanical properties. Conclusions and Prospects Several advanced manufacturing and processing technologies have been successfully industrialized, and commercial production lines have been established. This has enabled the fabrication of high-performance, multifunctional, complex, miniaturized, and lightweight components, as well as high-value recycled plastic products that cannot be produced using conventional processing methods. These innovations have been widely applied in fields such as new energy vehicles, electronics, and construction, delivering substantial economic and social benefits.
国民经济和高新技术的高速发展迫切需要轻质、高强、耐高温、多功能的高分子泡沫材料和制品。但常规发泡技术仅能制备通用高分子泡沫材料和制品,存在力学性能、耐热性能较差、组分单一、功能性缺乏、易燃烧、难阻燃等问题,且传统加压水蒸气熔接温度仅为120~180 ℃,不适用于高熔点、高玻璃化转变温度的工程塑料,高性能多功能高分子泡沫材料和制品的制备仍是世界难题。团队与加拿大多伦多大学Chul B. Park院士团队合作,共建了四川大学‒多伦多大学国际聚合物发泡研究中心,建立和发展了高性能多功能高分子泡沫材料和制品的先进制造装备、技术和理论,制备了常规发泡技术不能制备的系列高性能多功能高分子泡沫材料和制品,为国民经济发展提供关键材料。
WangQi, XiaHesheng, ChenYinghong,et al.Preparation and micro injection molding processing of polymer based micro/nanocomposites[J].Materials China,2014,33(4):224‒231.
LiLi, XuDawei, BaiShibing,et al.Progress in preparation of high-performance and multi-functional polymer foams[J].Journal of Polymer Science,2024,62(14):3122‒3136. doi:10.1002/pol.20230490
[8]
YangShuangqiao, WangFujie, PuZhilong,et al.High-quality recycling and remanufacturing of decommissioned wind turbine blades[J].Scientia Sinica(Chimica),2026,56(3):619‒628.
WangQi, LiLi, ChenNing,et al.Preparation of high performance polymer materials through intermolecular complexation[J].Acta Polymerica Sinica,2011,42(9):932‒938.
YangShuangqiao, BaiShibing, WangQi.Sustainable packaging biocomposites from polylactic acid and wheat straw:Enhanced physical performance by solid state shear milling process[J].Composites Science and Technology,2018,158:34‒42. doi:10.1016/j.compscitech.2017.12.026
[19]
YangShuangqiao, ZhongFeng, WangMeng,et al.Recycling of automotive shredder residue by solid state shear milling technology[J].Journal of Industrial and Engineering Chemistry,2018,57:143‒153. doi:10.1016/j.jiec.2017.08.016
[20]
KangPeiling, YangShuangqiao, BaiShibing,et al.Novel application of mechanochemistry in waste epoxy recycl-ing via solid-state shear milling[J].ACS Sustainable Che-mistry & Engineering,2021,9(35):11778‒11789. doi:10.1021/acssuschemeng.1c03221
[21]
QiFangwei, ChenNing, WangQi.Preparation of PA11/BaTiO3 nanocomposite powders with improved processability,dielectric and piezoelectric properties for use in selective laser sintering[J].Materials & Design,2017,131:135‒143. doi:10.1016/j.matdes.2017.06.012
[22]
YangShuangqiao, WeiBaojie, XuDawei,et al.Application of aluminum-plastic packaging and new recycling technology of the waste[J].CIESC Journal,2022,73(8):3326‒3337.
SunFasen, YangShuangqiao, BaiShibing,et al.Reuse of Pan-milled P‒XLPE cable powder as additive for asphalt to improve thermal stability and decrease processing viscosity[J].Construction and Building Materials,2021,281:122593. doi:10.1016/j.conbuildmat.2021.122593
[25]
HePan, BaiShibing, WangQi.Structure and performance of poly(vinyl alcohol)/wood powder composite prepared by th-ermal processing and solid state shear milling technology[J].Composites Part B:Engineering,2016,99:373‒380. doi:10.1016/j.compositesb.2016.06.006
[26]
PeiHaoran, XieYeping, XiongYu,et al.A novel polarization-free 3D printing strategy for fabrication of poly(Vinylidene fluoride) based nanocomposite piezoelectric energy harvester[J].Composites Part B:Engineering,2021,225:109312. doi:10.1016/j.compositesb.2021.109312
[27]
PeiHaoran, JingJingjing, ChenYinghong,et al.3D printing of PVDF-based piezoelectric nanogenerator from programmable metamaterial design:Promising strategy for flexible electronic skin[J].Nano Energy,2023,109:108303. doi:10.1016/j.nanoen.2023.108303
[28]
ChenGang, ChenNing, WangQi.Fabrication and properties of poly(vinyl alcohol)/β-tricalcium phosphate composite scaffolds via fused deposition modeling for bone tissue engineering[J].Composites Science and Technology,2019,172:17‒28. doi:10.1016/j.compscitech.2019.01.004
[29]
SongShiping, LiYijun, BaiShibing,et al.Production of spherical polymeric composite powder for selective laser sintering via plasma assisted solid state shear milling:From theory to piezoelectric application[J].Chemical Engineering Journal,2021,415:129035. doi:10.1016/j.cej.2021.129035
[30]
PeiHaoran, ShiShaohong, ChenYinghong,et al.Combining solid-state shear milling and FFF 3D-printing strategy to fabricate high-performance biomimetic wearable fish-scale PVDF-based piezoelectric energy harvesters[J].ACS Applied Materials & Interfaces,2022,14(13):15346‒15359. doi:10.1021/acsami.2c02491
[31]
PeiHaoran, ChenYinghong, LvQinniu,et al.A novel microwave assisted multi-material 3D printing strategy to architect lamellar piezoelectric generators for intelligent sensing[J].Composites Part B:Engineering,2024,280:111529. doi:10.1016/j.compositesb.2024.111529
[32]
LvQinniu, TaoXingyu, ShiShaohong,et al.From materials to components:3D-printed architected honeycombs tow-ard high-performance and tunable electromagnetic interference shielding[J].Composites Part B:Engineering,2022,230:109500. doi:10.1016/j.compositesb.2021.109500
[33]
LvQinniu, PengZilin, PeiHaoran,et al.3D printing of periodic porous metamaterials for tunable electromagnetic sh-ielding across broad frequencies[J].Nano‒Micro Letters,2024,16(1):279. doi:10.1007/s40820-024-01502-5
YangSen, ChenYinghong, YangChaonan,et al.The morphology evolution and crystallization behavior of microinjection molded polyoxymethylene/molybdenum disulfide nanocomposite[J].Journal of Applied Polymer Science,2017,134(12):app.44625. doi:10.1002/app.44625
[36]
FengShuo, ZhouXinwen, YangSen,et al.Preparation of polyoxymethylene/exfoliated molybdenum disulfide nanocomposite through solid-state shear milling[J].Polymers,2024,16(10):1334. doi:10.3390/polym16101334
[37]
TanJiayu, LiTao, XieYeping,et al.Fabricating high-per-formance biomedical PLLA/PVDF blend micro bone screws through in situ structuring of oriented PVDF su-bmicron fibers in microinjection molding[J].Composites Part B:Engineering,2024,281:111567. doi:10.1016/j.compositesb.2024.111567
[38]
PeiH, TanJ, PengZ,et al.Ultra-precise sensing in PVDF piezoelectric nanogenerator with self-oriented nanocrystals via multi-level counter-chain relaxation strategy[J].Nano Energy,2025,138:110847. doi:10.1016/j.nanoen.2025.110847
[39]
DingWeiwei, ChenYinghong, LiuZhuo,et al. In situ nano-fibrillation of microinjection molded poly(lactic acid)/poly(ε-caprolactone) blends and comparison with conventio-nal injection molding[J].RSC Advances,2015,5(113):92905‒92917. doi:10.1039/c5ra15402b
[40]
WangMeng, DingWeiwei, XieYeping,et al.Effect of micro-mold cavity dimension on structure and property of polylactic acid/polycaprolactone blend under microinjection molding conditions[J].Polymers,2021,13(6):887. doi:10.3390/polym13060887
[41]
ZhangKailin, LiXiao, NieMin,et al.Helical flow-driven alignment of off-axial silver-functionalized titanium dioxide fibers in polypropylene tube suitable for medical applications[J].Composites Science and Technology,2018,158:121‒127. doi:10.1016/j.compscitech.2018.02.022
[42]
LiYijun, NieMin, WangQi.Facile fabrication of electrically conductive low-density polyethylene/carbon fiber tubes for novel smart materials via multiaxial orientation[J].ACS Applied Materials & Interfaces,2018,10(1):1005‒1016. doi:10.1021/acsami.7b17131
[43]
NieMin, BaiShibing, WangQi.High-density polyethylene pipe with high resistance to slow crack growth prepared via rotation extrusion[J].Polymer Bulletin,2010,65(6):609‒621. doi:10.1007/s00289-010-0270-5
[44]
HanR, NieM, BaiS B,et al.Effect of the mandrel rotation speed and inner wall cooling rate on the performance and structure of polypropylene block-copolymer pipe[J].International Polymer Processing,2013,28(5):496‒505. doi:10.3139/217.2761
[45]
LiuWei, WangQi, NieMin.Structure and performance of polybutene-1 pipes produced via mandrel rotation extrusion[J].polyeng,2014,34(1):15‒22. doi:10.1515/polyeng-2013-0245
[46]
XieYeling, LiangWen, NieMin.Boosting circumferential mechanical strength of polylactic acid microtube through cooperative effects of orientation and conformation regulation[J].Polymer,2026,344:129562. doi:10.1016/j.polymer.2026.129562
[47]
YangChanghua, ShiShaohong, NieMin,et al.Boosted mechanical properties of polyamide 11 tube originated from the hierarchical architecture manipulation by helical flow field[J].ACS Sustainable Chemistry & Engineering,2023,11(6):2564‒2573. doi:10.1021/acssuschemeng.2c06808
[48]
WangLong, XuDawei, WangQi.Fabrication of polyimide bead foams via utilizing supercritical CO2 and ethanol as the co-foaming agents[J].Journal of Applied Polymer Science,2026,143(19):e70621. doi:10.1002/app.70621
[49]
FengDong, LiuPengju, WangQi.Carbon nanotubes in microwave-assisted foaming and sinter molding of high performance polyetherimide bead foam products[J].Materials Science and Engineering:B,2020,262:114727. doi:10.1016/j.mseb.2020.114727
[50]
XuDawei, LiuPengju, WangQi.An ultrafast and clean method to manufacture poly(vinyl alcohol) bead foam products[J].Polymers for Advanced Technologies,2021,32(1):210‒219. doi:10.1002/pat.5076
[51]
FengDong, LiuPengju, WangQi.Selective microwave sintering to prepare multifunctional poly(ether imide) bead foams based on segregated carbon nanotube conductive network[J].Industrial & Engineering Chemistry Research,2020,59(13):5838‒5847. doi:10.1021/acs.iecr.0c00090
[52]
YangCheng, SongShiping, ChenFang,et al.Fabrication of PVDF/BaTiO3/CNT piezoelectric energy harvesters with bionic balsa wood structures through 3D printing and supercritical carbon dioxide foaming[J].ACS Applied Materials & Interfaces,2021,13(35):41723‒41734. doi:10.1021/acsami.1c11843
[53]
MaWenjie, LiuPengju, XuDawei,et al.High-strength and antistatic PET/CNTs bead foams prepared by scCO2 foaming and microwave sintering[J].Polymers for Advanced Technologies,2022,33(7):2211‒2220. doi:10.1002/pat.5672
[54]
WenChengzhen, XuDawei, WangQi.Preparation of bio-based flame-retardant poly(vinyl alcohol) foams with improved cell structure and mechanical performance[J].European Polymer Journal,2025,223:113670. doi:10.1016/j.eurpolymj.2024.113670
[55]
YeXin, XuDawei,et al.Enhancing the antishrinkage and mechanical performances of the PBAT/PVA foam for environment-friendly packaging[J].Industrial & Engineering Chemistry Research,2024,63(44):18997‒19006. doi:10.1021/acs.iecr.4c03356
[56]
QinQiange, ZhouTing, WangMeng,et al.Structure evolution and performance of poly(vinyl alcohol) fibers with controllable cross-section fabricated using a combination of melt-spinning and stretching[J].Polymer Testing,2023,117:107867. doi:10.1016/j.polymertesting.2022.107867
[57]
WangMeng, ChenNing.Preparation of trilobal poly(vinyl alcohol) fiber and its reinforcement for cement-based co-mposite materials[J].Polymer Materials Science & Engineering,2020,36(6):102‒109.
ZhouTing, WangMeng, ChenNing.Study on preparation of triangular melt-spinning poly(vinyl alcohol) fibers and its fabric strengthening and toughening epoxy[J].Polym-ers,2021,13(13):2204. doi:10.3390/polym13132204
[60]
ZhangJiayu, LiuEnhui, WangXuan,et al.Fabrication of poly(vinyl alcohol) film for antimicrobial food packaging via thermal processing:Synergistic effect of plasticization and crosslinking of citric acid[J].Journal of Applied Polymer Science,2026,143(17):e70585. doi:10.1002/app.70585
[61]
WangQingqing, XuDawei, WangQi.Novel PVA-based foams for cold chain logistics with high efficiency[J].Polymer,2024,302:127092. doi:10.1016/j.polymer.2024.127092
LiuZhaogang, LuHongchao, ZhangHuili,et al.Poly(vinyl alcohol)/polylactic acid blend film with enhanced processability,compatibility,and mechanical property fabricated via melt processing[J].Journal of Applied Polymer Science,2021,138(41):51204. doi:10.1002/app.51204
[65]
ZengShulong, DengSiwen, LiLi.Interface-compatible poly(vinyl alcohol)/poly(butylene adipate-co-terephthalate) blown films for soil-friendly disposable packaging[J].Polymer,2026,343:129483. doi:10.1016/j.polymer.2025.129483
[66]
WangXuan, ZhangJiayu, LiLi.A novel polypropylene carbonate/poly(vinyl alcohol) blend with multiple-shape memory functions and self-healing behavior fabricated via phase structure regulation[J].Industrial & Engineering Chemistry Research,2025,64(21):10485‒10495. doi:10.1021/acs.iecr.5c00728
[67]
ZhangJiayu, LiuEnhui, WangXuan,et al.Bamboo-derived lignocellulose prepared via one-step method with the assistance of microwave and its impact on poly(vinyl alcohol) film[J].Polymer Engineering & Science,2026,66(7):5167‒5180. doi:10.1002/pen.70569
[68]
LiuEnhui, ZhangHuili, LiLi.Fabrication of high performance poly(vinyl alcohol)/straw composite film used for package via melt casting and biaxial stretching[J].International Journal of Biological Macromolecules,2024,278:134675. doi:10.1016/j.ijbiomac.2024.134675
ZhuLongji, XuDawei, WangQi.Fabrication of poly(vinyl alcohol)/sulfonated itaconic starch blend film with enhanced antibacterial performance and soil absorption capacity for environment-friendly packaging[J].Carbohydrate Polymers,2025,357:123489. doi:10.1016/j.carbpol.2025.123489
[71]
ChenZhaohui, PuLian, LiLi.Fabrication of high-performance poly(vinyl alcohol) tubes via stable melt extrusion by reversible crosslinking of boric acid[J].Polymers for Advanced Technologies,2024,35:e6229. doi:10.1002/pat.6229
[72]
ChenZhaohui, PuLian, LiLi.Boosted gasoline transport performance of poly(vinyl alcohol) tubes by constructing wear-resistant and hydrophobic coatings on the surface[J].Industrial & Engineering Chemistry Research,2024,63(35):15534‒15545. doi:10.1021/acs.iecr.4c02138
[73]
ChenZhaohui, WangXuan, LiLi.Dual-functional PVA based microtubes:Leveraging natural lubrication and surface modification for antibacterial interventions[J].Polymer,2026,344:129508. doi:10.1016/j.polymer.2025.129508
[74]
ZhangLimei, XieYeping, LiLi.Fabrication of poly(vinyl alcohol) foam/gel composite used for cold storage by com-bing molding foaming and freeze-thawing technologies[J].Polymer Testing,2024,131:108350. doi:10.1016/j.polymertesting.2024.108350
[75]
LiuYuan, WangQi.Catalytic action of phospho-tungstic acid in the synthesis of melamine salts of pentaerythritol phosphate and their synergistic effects in flame retarded polypropylene[J].Polymer Degradation and Stability,2006,91(10):2513‒2519. doi:10.1016/j.polymdegradstab.2006.03.009
[76]
HanYi, XuYi, LiuYuan,et al.An efficient interfacial flame-resistance mode to prepare glass fiber reinforced and fla-me retarded polyamide 6 with high performance[J].Journal of Materials Chemistry A,2013,1(35):10228. doi:10.1039/c3ta11312d
[77]
XieWang, HanZhongqiang, ZhangZhaodi,et al.Hydrogen bond complexasion to prepare guanidine phosphate flame retardant poly(vinyl alcohol) membrane with high transparency[J].Composites Part B:Engineering,2019,176:107265. doi:10.1016/j.compositesb.2019.107265
[78]
XieWang, BaoQiuru, LiuYuan,et al.Hydrogen bond association to prepare flame retardant polyvinyl alcohol film with high performance[J].ACS Applied Materials & Interfaces,2021,13(4):5508‒5517. doi:10.1021/acsami.0c19093
[79]
ChenWenhua, LiuPengju, LiuYuan,et al.Interfacial carbonation for efficient flame retardance of glass fiber-reinforced polyamide 6[J].Polymer Chemistry,2015,6(24):4409‒4414. doi:10.1039/c5py00280j
[80]
JiangJun, ChengYanbo, LiuYuan,et al.Intergrowth charring for flame-retardant glass fabric-reinforced epoxy re-sin composites[J].Journal of Materials Chemistry A,2015,3(8):4284‒4290. doi:10.1039/c4ta06486k