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. 2026 May 13;59(10):6042–6048. doi: 10.1021/acs.macromol.6c00676

Surface-Initiated Hydrogen Atom Transfer Reversible Addition–Fragmentation Chain Transfer Polymerization from Isotactic Polypropylene

Anna E Ringuette †, Gozde Aktas Eken ‡, Amaya B Garnenez †, Christopher K Ober ‡, Geoffrey W Coates †,*, Brett P Fors †,*
PMCID: PMC13217618  PMID: 42222583

Abstract

Functionalizing isotactic polypropylene (iPP) surfaces with polymer brushes is of interest for biomedical materials, automotive parts, filtration, and packaging applications. Existing methods to graft from iPP require multiple synthetic steps or harsh stimuli such as γ-rays to initiate polymerization. Here, we describe surface-initiated hydrogen atom transfer reversible addition–fragmentation chain transfer polymerization (SI HAT-RAFT) from iPP to initiate controlled polymerization directly from the C–H bonds of iPP using visible light as a stimulus. Using a thioxanthone-derived photocatalyst and bis­(trithiocarbonate) disulfide species for catalyst turnover, we achieve thick polymer brushes using a variety of acrylic monomers. Furthermore, we grafted from commercial iPP samples, including food packaging and surgical mesh. Finally, we demonstrate improved surface properties of iPP by testing the adhesion of grafted polymer surfaces to paint and aluminum. We expect this method will be an enabling technology for preparing a wide range of iPP materials.

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Introduction

Since its discovery by Natta in 1954, isotactic polypropylene (iPP) has become one of the world’s most prevalent plastics, comprising about 19% of global plastic production. While iPP has found use in a wide range of commercial and consumer applications, its performance is often limited by poor surface properties. For example, the highly hydrophobic nature of iPP surfaces leads to weak adhesion, poor wetting, and a propensity for biofouling. These characteristics can be a drawback for the use of iPP in automotive materials, membrane filters, , and biomedical devices. Adding new surface functionality to iPP would be beneficial for the preparation of materials with enhanced properties, including antimicrobial high touch surfaces, , biocompatible surgical implements, − and other higher performing iPP materials. ,

Currently, few options exist for polypropylene surface functionalization. One commonly employed method for polypropylene surface modification is oxidation with plasma or a strong acid. ,− While this strategy increases hydrophilicity, the resulting small molecules grafted from the surface display poor stability over time and are limited to carboxylic acid and alcohol functional groups. In contrast to small molecule modifications, grafting polymers from iPP surfaces affords longer lived and more diverse surface functionality. Free radical polymerizations of acrylic monomers can be initiated from iPP surfaces by plasma or γ-ray activation. However, these conditions are harsh and typically yield only modest amounts of grafting. Controlled radical polymerization methods, in particular reversible addition–fragmentation chain transfer polymerization (RAFT) and atom transfer radical polymerization (ATRP), have also previously been used to functionalize iPP surfaces. While these strategies offer control over polymer growth, such methods require iterative synthetic modifications to iPP and often still rely on harsh stimuli such as γ-rays to functionalize the surface. − In order to easily access a diverse array of surface-functionalized iPP materials, a direct method to graft polymer brushes from iPP surfaces using mild stimuli is desirable.

Our group recently reported the functionalization of polyethylene (PE) surfaces using surface-initiated hydrogen atom transfer reversible addition–fragmentation chain transfer (SI HAT-RAFT) polymerization (Figure ). Using a benzophenone derived photocatalyst, a disulfide species, and monomer, we synthesized high density polymer brushes and demonstrated improved polyethylene surface properties. We hypothesized that due to the similar nature of C–H bonds in HDPE and iPP, this system would be amenable to iPP surfaces as well. However, when we subjected iPP to our polyethylene SI HAT-RAFT conditions, we observed comparably modest grafting by infrared spectroscopy (IR; Figure b, catalyst 2a). Additionally, Feng and co-workers report that SI HAT-RAFT from polypropylene surfaces required multiday reactions and additional heat to achieve modest functionalization. Here, we describe the design of an improved system for surface functionalization of iPP by leveraging long-lived thioxanthone (TX) catalysts.

1.

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Surface-initiated HAT-RAFT from iPP allows for access to thick polymer brushes and improved surface properties.

2.

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(a) General reaction scheme for SI HAT-RAFT from iPP. (b) IR spectra of photocatalyst screen with diagnostic CO stretch highlighted.

Results and Discussion

We began our investigation of iPP surface functionalization by surveying photocatalysts to mediate the HAT initiation step (Figure ). We started with benzophenone derived catalyst 2a, which we previously used to functionalize PE surfaces. In spite of its activity for PE, the IR spectrum following SI HAT-RAFT shows that catalyst 2a produces limited surface functionalization of iPP (Figure b). HAT from iPP has been reported to be far slower at all positions than HAT from HDPE due to steric hindrance from the methyl group on the polymer backbone, which in turn decreases grafting efficiency. , We hypothesized that using a photocatalyst with a longer excited state lifetime would increase the probability of abstracting a hydrogen atom from the surface of iPP, thereby increasing grafting efficiency. As a result, we focused our efforts on the thioxanthone class of catalysts. Thioxanthone is reported to have an excited state lifetime that is 2 orders of magnitude greater than benzophenone. Within this catalyst class, we further elected to focus on those substituted at the 2 and 7 positions. These thioxanthone derivatives have red-shifted λmax relative to unsubstituted thioxanthone, which absorbs primarily ultraviolet light. This red shift allowed us to use the same highly accessible compact fluorescent light (CFL) as a light source, which emits strongly from 400 to 700 nm (Figure S1), for all catalysts screened. With these design parameters in mind, we evaluated thioxanthone catalysts 2b, 2c, and 2d (Figure ) for SI HAT-RAFT.

All three of our selected TX-derived catalysts (2b, 2c, and 2d) outperformed benzophenone derivative 2a, supporting our hypothesis that the longer excited state lifetime of these catalysts would increase iPP functionalization (Figure ). Of the three TX catalysts tested, bis­(methoxy) substituted 2d led to the greatest amount of grafting, followed by isopropyl substituted 2c and then bis­(piperidine) substituted 2b, respectively. The piperidine functional group on 2b contains hydridic C–H bonds, and is likely to be competitively abstracting hydrogen atoms from other catalysts instead of the iPP surface, leading to decreased surface grafting. To better understand the difference in performance between 2c and 2d, we evaluated our catalysts by UV–vis spectroscopy (Figure S3, S4, S5). This revealed improved overlap in the absorbance spectrum of bis­(methoxy) substituted 2d (λmax = 384 nm, ε = 2280 M–1 cm–1) with our light source relative to isopropyl substituted 2c (λmax = 415 nm, ε = 4630 M–1 cm–1), and a greater extinction coefficient, leading to the observed grafting trends (Table S1). For these reasons, we moved forward with catalyst 2d.

With our optimized TX-derived catalyst and SI HAT-RAFT conditions in hand, we next carried out a series of control experiments to probe the mechanism of polymerization (Table ). First, to confirm the covalent nature of our observed grafting, we drop-cast poly tert-butyl acrylate (P t BuA) onto unfunctionalized iPP and subjected it to our washing conditions for grafted films. No remaining P t BuA was observed by IR, supporting that the polymer observed under SI HAT-RAFT conditions is covalently bound (Table , entry 2). To understand how the radical generation mechanism affects grafting, we exposed iPP to thermal RAFT polymerization conditions (Table , entry 3). Thermal RAFT in the presence of an iPP film did not lead to grafting of P t BuA by IR, confirming the necessity of an efficient HAT mediator for grafting. Additionally, we wanted to ensure that catalyst 2d was not abstracting hydrogen atoms from the backbone of the grafted acrylates. Polyethylene terephthalate (PET), a substrate with no hydridic C–H bonds, had no observable grafting when subjected to SI HAT-RAFT conditions (Table , entry 4). This selectivity for hydridic C–H bonds is consistent with prior reports of aryl ketone photocatalysts, and suggests that catalyst 2d is not abstracting hydrogen atoms from the backbone of grafted acrylates to generate branching.

1. iPP Functionalization Controls.

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entry conditions ratio CO:CH2 stretch
1 standard conditions 1.2:1.0
2 drop cast P t BuA onto iPP 0.0:1.0
3 thermal RAFT 0.0:1.0
4 PET instead of iPP 0.0:1.0
5 no CFL 0.0:1.0
6 no catalyst (2d) 0.0:1.0
7 no disulfide (1) 0.6:1.0
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a

P t BuA dissolved in DCM, drop cast onto melt-pressed iPP, and washed with DCM to remove.

b

CTA, AIBN, tert-butyl acrylate, and iPP immersed in dioxane, degassed, and heated to 70 °C.

c

No increase in CO stretch intensity.

Furthermore, polymerization does not proceed in absence of light or photocatalyst (Table , entries 5 and 6). In the absence of the disulfide species, polymerization proceeds to only half of the intensity by IR, suggesting that the disulfide is critical to enabling a significant amount of grafting (Table , entry 7). Additionally, sulfur in the XPS spectrum and thermal chain extension experiments (Figures S37 and S22) support the presence of the trithiocarbonate on the chain ends of grafted polymers. We propose that SI HAT-RAFT from iPP proceeds in a mechanism consistent with that previously described for HDPE. Catalyst 2d is excited by visible light and abstracts a tertiary hydrogen atom, ,− generating a carbon-centered radical that initiates polymerization. Disulfide 1 cleaves under visible light to yield two equivalents of trithiocarbonyl radical. One equivalent of trithiocarbonyl radical caps the growing polymer chain to generate a RAFT macro-CTA. The other equivalent of trithiocarbonyl radical goes on to turn over the catalyst, leading to multiple rounds of hydrogen atom transfer per catalyst. We posit that catalyst turnover by the trithiocarbonate species is responsible for the efficient grafting observed.

To further characterize our brushes, we carried out optical profilometry on spin-coated iPP films. Azide-functionalized wafers were spin-coated with iPP, scratched with a razor blade, and the step height of the scratch was measured before and after SI HAT-RAFT. Using this method, iPP-g-P t BuA brushes were measured to be 143 nm thick (Figure ). There are few reports quantifying the brush thickness of polymer brushes grafted with controlled polymerization methods from iPP. Using ATRP, 60 nm thick polymer brushes grafted from iPP copolymers have been attained. SI HAT-RAFT produces thick brushes on iPP in a facile, single-step functionalization.

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Optical profilometer characterization of iPP-g-P t BuA brush thickness on spin-coated iPP films. Brush thickness is assessed by comparing the step height of iPP film before and after grafting. Brush thickness is 143 nm.

To demonstrate the versatility of SI HAT-RAFT for improving iPP surface properties, we prepared grafted iPP samples using a range of monomers and substrates (Figure ). Poly­(methyl acrylate) (PMA), P t BuA, and poly­(methyl methacrylate) (PMMA) brushes all lead to a moderate decrease in the water contact angle of iPP (Figure a). Water-soluble poly­(sodium acrylate) (PNaA) brushes lower the water contact angle even further, showcasing the ability of SI HAT-RAFT to prepare hydrophilic iPP surfaces (Figure a). Additionally, SI HAT-RAFT is amenable to syndiotactic polypropylene, which grafts with comparable efficiency to iPP (Figure S31). We also successfully grafted directly from commercial samples of iPP, including a food container lid and surgical mesh. Functionalization of surgical mesh is of particular interest for its demonstrated capacity to reduce inflammatory response and occurrence of infection. , Reported strategies for functionalizing polypropylene mesh rely almost exclusively on plasma pretreatment. − However, plasma treatment has been reported to negatively impact the brittleness of polypropylene surgical mesh, while brush growth has modest positive impacts on its mechanical properties. Thus, our single-step polymerization with only mild visible light stimulus may be particularly impactful for its applications to iPP biomedical materials.

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(a) Monomer scope of SI HAT-RAFT under standard reaction conditions: disulfide 1 (1 equiv), catalyst 2d (1 equiv), monomer (200 equiv), and dioxane irradiated with a CFL at room temperature in a nitrogen atmosphere for 16 h. (b) Functionalization of common commercial iPP sources with P t BuA brushes.

We were also interested in using SI HAT-RAFT to prepare iPP surfaces patterned with polymer brushes, which may be useful for antifouling and electronic applications. The light-dependence of the SI HAT-RAFT mechanism (Table , entry 5) indicated that spatial control could be achieved with our method. We used a photomask designed with an array of 500 μm by 500 μm squares to pattern PMA brushes on a melt-pressed iPP film (Figure a). By both optical and stylus profilometry, these square grafted regions were up to 15 μm thick (Figure b, Figure S36). We hypothesize that the thicker iPP substrate layer of the patterned films generates a thicker layer of grafted polymer because in addition to initiating polymer brushes from the iPP surface, the catalyst and monomer solution can swell further into the substrate and initiate chains within the bulk of iPP. Grafted polymer thicknesses on the micron scale have been observed previously in the literature for other polymer-initiated systems in which monomer is able to swell into the substrate, including examples from iPP with up to 2 μm thick polymer grafts. Additionally, free PMA formed in the tandem solution polymerization has an M n of 16.3 kg/mol, which is far smaller than the molecular weight required to achieve 15 μm long PMA brushes (Figure S38). Nevertheless, the ability to pattern iPP surfaces facilitates the use of SI HAT-RAFT in a wide range of applications.

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(a) Optical image of iPP-g-PMA patterned surface sputter-coated with a thin layer of Au/Pd. The surface was patterned using a photomask with an array of 500 × 500 μm squares. (b) Stylus profilometer characterization of iPP-g-PMA thickness on melt-pressed iPP films. Graft thickness is measured as the step height from the ungrafted to the grafted regions of the patterned film. Height of the grafted region is 15 μm.

Finally, we carried out adhesion tests on iPP samples functionalized with SI HAT-RAFT (Figure ). First, we performed a tape test to assess paint adhesion Figure a). We prepared iPP samples grafted with poly­(methyl methacrylate) (PMMA) and poly­(n-butyl acrylate) (P n BuA) copolymers that mimic the composition of acrylic paint. We then painted both grafted and ungrafted iPP films with acrylic paint and applied a piece of tape. Upon removing the tape, all paint was removed from the unfunctionalized iPP, while all of the paint remained on the grafted surface. This distinction in paint adhesion is a clear visual demonstration of the capacity for SI HAT-RAFT to modify iPP surface properties.

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(a) Tape test comparing adhesion of iPP (left) and iPP-g-(PMMA-co-P n BuA) (right) to acrylic paint. (b) Lap shear test comparing adhesion of iPP and iPP-g-PAA to aluminum surfaces.

In addition to the tape test, we were interested in testing the ability of our grafted iPP to adhere to other application relevant materials. One common application of iPP is for use as a metal/thermoplastic composite in automotive parts. − However, the low surface energy of iPP often leads to poor adhesion at the iPP/metal interface. Modifying iPP with more polar functionalities such as maleic anhydride, glycidyl methacrylate, and acrylic acid has been previously shown to be an effective strategy for improving adhesion to aluminum by increasing noncovalent interactions at the interface of iPP and aluminum. − With this in mind, we carried out a lap shear test to determine if SI HAT-RAFT could improve adhesion of iPP to aluminum (Figure b). While unfunctionalized iPP was unable to form a lap joint between aluminum substrates, iPP-g-poly­(acrylic acid) (PAA) adhered to aluminum with a shear force of 1.2 MPa, demonstrating the value of SI HAT-RAFT for improving the adhesive properties of iPP.

Conclusions

In conclusion, we have designed an SI HAT-RAFT polymerization system to graft thick polymer brushes from the surface of iPP. By employing long-lived thioxanthone catalysts to mediate HAT, we were able to overcome hampered initiation that arises from steric hindrance. The brushes generated from SI HAT-RAFT of iPP are among the thickest reported from iPP-type polymers. Our method is amenable to a variety of monomers and iPP substrates, including surgical mesh, making it a promising route to higher performing biomedical materials. We were also able to demonstrate an improvement in iPP adhesion to other materials, including paint and aluminum. We envision that this method will enable the preparation of iPP materials with improved surface properties.

Supplementary Material

ma6c00676_si_001.pdf (4.5MB, pdf)

Acknowledgments

This work was supported by the NSF under Award CHE-2203758. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under grant no. DGE-2139899. G.A.E. was supported by the NSF under Award CHE-2304838. This work made use of the Cornell Center for Materials Research Shared Facilities. This work was performed in part at the Cornell NanoScale Science and Technology Facility (CNF), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant NNCI-2025233). C.K.O. acknowledges support by the National Science Foundation during his time as a V.S.E.E. rotator. Views expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.macromol.6c00676.

  • Materials and Methods; Procedures for synthesis and purification of materials; Characterization by IR, water contact angle, XPS, profilometry, lap shear testing, and tape testing (PDF)

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.

The authors declare no competing financial interest.

References

  1. Natta G., Pino P., Corradini P., Danusso F., Mantica E., Mazzanti G., Moraglio G.. Crystalline High Polymers of α-Olefins. J. Am. Chem. Soc. 1955;77:1708–1710. doi: 10.1021/ja01611a109. [DOI] [Google Scholar]
  2. Houssini K., Li J., Tan Q.. Complexities of the global plastics supply chain revealed in a trade-linked material flow analysis. Commun. Earth Environ. 2025;6:257. doi: 10.1038/s43247-025-02169-5. [DOI] [Google Scholar]
  3. Brewis D. M., Briggs D.. Adhesion to polyethylene and polypropylene. Polymer. 1981;22:7–16. doi: 10.1016/0032-3861(81)90068-9. [DOI] [Google Scholar]
  4. Carrino L., Moroni G., Polini W.. Cold plasma treatment of polypropylene surface: a study on wettability and adhesion. J. Mater. Process. Technol. 2002;121:373–382. doi: 10.1016/S0924-0136(01)01221-3. [DOI] [Google Scholar]
  5. Reid K., Dixon M., Pelekani C., Jarvis K., Willis M., Yu Y.. Biofouling control by hydrophilic surface modification of polypropylene feed spacers by plasma polymerization. Desalination. 2014;335:108–118. doi: 10.1016/j.desal.2013.12.017. [DOI] [Google Scholar]
  6. Ayas K., Karaca A., Çetinkaya İ. H., Kanbir Ö., Çavdar K.. Investigation of the effects of atmospheric pressure plasma on polypropylene automotive bumper surface and its paintability with and without primer. Polym. Eng. Sci. 2025;65:2106–2118. doi: 10.1002/pen.27140. [DOI] [Google Scholar]
  7. Le-Clech P., Chen V., Fane T. A. G.. Fouling in membrane bioreactors used in wastewater treatment. J. Membr. Sci. 2006;284:17–53. doi: 10.1016/j.memsci.2006.08.019. [DOI] [Google Scholar]
  8. Flemming H.-C., Schaule G., Griebe T., Schmitt J., Tamachkiarowa A.. Biofoulingthe Achilles heel of membrane processes. Desalination. 1997;113:215–225. doi: 10.1016/S0011-9164(97)00132-X. [DOI] [Google Scholar]
  9. Meyers S. R., Grinstaff M. W.. Biocompatible and Bioactive Surface Modifications for Prolonged In Vivo Efficacy. Chem. Rev. 2012;112:1615–1632. doi: 10.1021/cr2000916. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Liu M., Bauman L., Nogueira C. L., Aucoin M. G., Anderson W. A., Zhao B.. Antimicrobial polymeric composites for high-touch surfaces in healthcare applications. Curr. Opin. Biomed. Eng. 2022;22:100395. doi: 10.1016/j.cobme.2022.100395. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cobrado L., Silva-Dias A., Azevedo M. M., Rodrigues A. G.. High-touch surfaces: microbial neighbours at hand. Eur. J. Clin. Microbiol. Infect. Dis. 2017;36:2053–2062. doi: 10.1007/s10096-017-3042-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Emans P. J., Schreinemacher M. H. F., Gijbels M. J. J., Beets G. L., Greve J.-W. M., Koole L. H., Bouvy N. D.. Polypropylene Meshes to Prevent Abdominal Herniation. Can Stable Coatings Prevent Adhesions in the Long Term? Ann. Biomed. Eng. 2009;37:410–418. doi: 10.1007/s10439-008-9608-7. [DOI] [PubMed] [Google Scholar]
  13. Hazer D. B., Mut M., Dinçer N., Saribas Z., Hazer B., Özgen T.. The efficacy of silver-embedded polypropylene-grafted polyethylene glycol-coated ventricular catheters on prevention of shunt catheter infection in rats. Childs Nerv. Syst. 2012;28:839–846. doi: 10.1007/s00381-012-1729-5. [DOI] [PubMed] [Google Scholar]
  14. Saha T., Houshyar S., Ranjan Sarker S., Ghosh S., Dekiwadia C., Padhye R., Wang X.. Surface-Functionalized Polypropylene Surgical Mesh for Enhanced Performance and Biocompatibility. ACS Appl. Bio Mater. 2019;2:5905–5915. doi: 10.1021/acsabm.9b00849. [DOI] [PubMed] [Google Scholar]
  15. Ma Y., Wisuthiphaet N., Bolt H., Nitin N., Zhao Q., Wang D., Pourdeyhimi B., Grondin P., Sun G.. N-Halamine Polypropylene Nonwoven Fabrics with Rechargeable Antibacterial and Antiviral Functions for Medical Applications. ACS Biomater. Sci. Eng. 2021;7:2329–2336. doi: 10.1021/acsbiomaterials.1c00117. [DOI] [PubMed] [Google Scholar]
  16. Maitz M. F.. Applications of synthetic polymers in clinical medicine. Biosurf. Biotribol. 2015;1:161–176. doi: 10.1016/j.bsbt.2015.08.002. [DOI] [Google Scholar]
  17. Cerkez I., Worley S. D., Broughton R. M., Huang T. S.. Antimicrobial surface coatings for polypropylene nonwoven fabrics. React. Funct. Polym. 2013;73:1412–1419. doi: 10.1016/j.reactfunctpolym.2013.07.016. [DOI] [Google Scholar]
  18. Liu Z.-M., Xu Z.-K., Wang J.-Q., Wu J., Fu J.-J.. Surface modification of polypropylene microfiltration membranes by graft polymerization of N-vinyl-2-pyrrolidone. Eur. Polym. J. 2004;40:2077–2087. doi: 10.1016/j.eurpolymj.2004.05.020. [DOI] [Google Scholar]
  19. Yang Y. F., Wan L. S., Xu Z. K.. Surface hydrophilisation and antibacterial functionalisation for microporous polypropylene membranes. Water Sci. Technol. 2010;61:2053–2060. doi: 10.2166/wst.2010.117. [DOI] [PubMed] [Google Scholar]
  20. Zhang D., Sun Q., Wadsworth L. C.. Mechanism of corona treatment on polyolefin films. Polym. Eng. Sci. 1998;38:965–970. doi: 10.1002/pen.10264. [DOI] [Google Scholar]
  21. Delorme N., Bardeau J.-F., Nicolas-Debarnot D., Bulou A., Poncin-Epaillard F.. New Route for the Elaboration of Polyolefin Surfaces Bearing Azo Molecules. Langmuir. 2003;19:5318–5322. doi: 10.1021/la026926x. [DOI] [Google Scholar]
  22. Bhat N. V., Upadhyay D. J.. Plasma-induced surface modification and adhesion enhancement of polypropylene surface. J. Appl. Polym. Sci. 2002;86:925–936. doi: 10.1002/app.11024. [DOI] [Google Scholar]
  23. Mühlhan C., Weidner St., Friedrich J., Nowack H.. Improvement of bonding properties of polypropylene by low-pressure plasma treatment. Surf. Coat. Technol. 1999;116–119:783–787. doi: 10.1016/S0257-8972(99)00203-0. [DOI] [Google Scholar]
  24. Blais P., Carlsson D. J., Csullog G. W., Wiles D. M.. The chromic acid etching of polyolefin surfaces, and adhesive bonding. J. Colloid Interface Sci. 1974;47:636–649. doi: 10.1016/0021-9797(74)90241-0. [DOI] [Google Scholar]
  25. Sheng E., Sutherland I., Brewis D. M., Heath R. J.. Effects of the chromic acid etching on propylene polymer surfaces. J. Adhes. Sci. Technol. 1995;9:47–60. doi: 10.1163/156856195X00284. [DOI] [Google Scholar]
  26. Abednejad A. S., Amoabediny G., Ghaee A.. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization. Mater. Sci. Eng., C. 2014;42:443–450. doi: 10.1016/j.msec.2014.05.060. [DOI] [PubMed] [Google Scholar]
  27. Barsbay M., Güven O.. RAFT mediated grafting of poly­(acrylic acid) (PAA) from polyethylene/polypropylene (PE/PP) nonwoven fabric via preirradiation. Polymer. 2013;54:4838–4848. doi: 10.1016/j.polymer.2013.06.059. [DOI] [Google Scholar]
  28. Wang Y., Wang L.-L., He X.-C., Zhang Z.-J., Yu H.-Y., Gu J.-S.. Integration of RAFT polymerization and click chemistry to fabricate PAMPS modified macroporous polypropylene membrane for protein fouling mitigation. J. Colloid Interface Sci. 2014;435:43–50. doi: 10.1016/j.jcis.2014.08.013. [DOI] [PubMed] [Google Scholar]
  29. Wu X.-M., Wang L.-L., Wang Y., Gu J.-S., Yu H.-Y.. Surface modification of polypropylene macroporous membrane by marrying RAFT polymerization with click chemistry. J. Membr. Sci. 2012;421–422:60–68. doi: 10.1016/j.memsci.2012.06.033. [DOI] [Google Scholar]
  30. Matsugi T., Saito J., Kawahara N., Matsuo S., Kaneko H., Kashiwa N., Kobayashi M., Takahara A.. Surface Modification of Polypropylene Molded Sheets by Means of Surface-Initiated ATRP of Methacrylates. Polym. J. 2009;41:547–554. doi: 10.1295/polymj.PJ2009034. [DOI] [Google Scholar]
  31. Huang J., Murata H., Koepsel R. R., Russell A. J., Matyjaszewski K.. Antibacterial Polypropylene via Surface-Initiated Atom Transfer Radical Polymerization. Biomacromolecules. 2007;8:1396–1399. doi: 10.1021/bm061236j. [DOI] [PubMed] [Google Scholar]
  32. Ringuette A. E., Aktas Eken G., Garnenez A. B., Palmieri A. I., Ober C. K., Coates G. W., Fors B. P.. Direct Functionalization of Polyethylene Surfaces with High-Density Polymer Brushes. J. Am. Chem. Soc. 2024;146:20563–20568. doi: 10.1021/jacs.4c06924. [DOI] [PubMed] [Google Scholar]
  33. Huang G., Wu Z., Liu Y., Chang L., Wang Z., Du X., Xu B., Jia Z., Feng C.. Commodity Polymer Functionalization by a Combination of Hydrogen Atom Transfer Reversible Addition-Fragmentation Chain Transfer Polymerization and Pentafluorophenyl-Ester-Ligation Chemistry. ACS Macro Lett. 2025;14:1038–1047. doi: 10.1021/acsmacrolett.5c00368. [DOI] [PubMed] [Google Scholar]
  34. Garrett G. E., Mueller E., Pratt D. A., Parent J. S.. Reactivity of Polyolefins toward Cumyloxy Radical: Yields and Regioselectivity of Hydrogen Atom Transfer. Macromolecules. 2014;47:544–551. doi: 10.1021/ma402177v. [DOI] [Google Scholar]
  35. Camara S., Gilbert B. C., Meier R. J., van Duin M., Whitwood A. C.. EPR and modelling studies of hydrogen-abstraction reactions relevant to polyolefin cross-linking and grafting chemistry. Org. Biomol. Chem. 2003;1:1181–1190. doi: 10.1039/b212543a. [DOI] [PubMed] [Google Scholar]
  36. Nikitas N. F., Gkizis P. L., Kokotos C. G.. Thioxanthone: a powerful photocatalyst for organic reactions. Org. Biomol. Chem. 2021;19:5237–5253. doi: 10.1039/D1OB00221J. [DOI] [PubMed] [Google Scholar]
  37. Elliott L. D., Kayal S., George M. W., Booker-Milburn K.. Rational Design of Triplet Sensitizers for the Transfer of Excited State Photochemistry from UV to Visible. J. Am. Chem. Soc. 2020;142:14947–14956. doi: 10.1021/jacs.0c05069. [DOI] [PubMed] [Google Scholar]
  38. Garwood J. J. A., Chen A. D., Nagib D. A.. Radical Polarity. J. Am. Chem. Soc. 2024;146:28034–28059. doi: 10.1021/jacs.4c06774. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Roberts B. P.. Polarity-reversal catalysis of hydrogen-atom abstraction reactions: concepts and applications in organic chemistry. Chem. Soc. Rev. 1999;28:25–35. doi: 10.1039/a804291h. [DOI] [Google Scholar]
  40. Niki E., Ohto N., Kanauchi T., Kamiya Y.. Hydrogen atom abstraction from polypropylene and polystyrene by t-butoxy radical site of radical attack studied by spin trapping. Eur. Polym. J. 1980;16:559–563. doi: 10.1016/0014-3057(80)90087-7. [DOI] [Google Scholar]
  41. Dokolas P., Loer S. M., Solomon D. H.. Reaction of Acyclic Hydrocarbons Towards t-Butoxy Radicals. A Study of Hydrogen Atom Abstraction by Using the Radical Trapping Technique. Aust. J. Chem. 1999;51:1113–1120. doi: 10.1071/C98055. [DOI] [Google Scholar]
  42. Heinen W., Rosenmöller C. H., Wenzel C. B., de Groot H. J. M., Lugtenburg J., van Duin M.. 13C NMR Study of the Grafting of Maleic Anhydride onto Polyethene, Polypropene, and Ethene-Propene Copolymers. Macromolecules. 1996;29:1151–1157. doi: 10.1021/ma951015y. [DOI] [Google Scholar]
  43. Yan M., Ren J.. Covalent immobilization of polypropylene thin films. J. Mater. Chem. 2005;15:523. doi: 10.1039/b410972d. [DOI] [Google Scholar]
  44. Liang M. K., Clapp M., Li L. T., Berger R. L., Hicks S. C., Awad S.. Patient Satisfaction, Chronic Pain, and Functional Status following Laparoscopic Ventral Hernia Repair. World J. Surg. 2013;37:530–537. doi: 10.1007/s00268-012-1873-9. [DOI] [PubMed] [Google Scholar]
  45. Labay C., Canal J. M., Modic M., Cvelbar U., Quiles M., Armengol M., Arbos M. A., Gil F. J., Canal C.. Antibiotic-loaded polypropylene surgical meshes with suitable biological behaviour by plasma functionalization and polymerization. Biomaterials. 2015;71:132–144. doi: 10.1016/j.biomaterials.2015.08.023. [DOI] [PubMed] [Google Scholar]
  46. Sethi V., Verma C., Mukhopadhyay S., Gupta A., Gupta B.. Oxidative functionalization of polypropylene mesh surface by radio frequency plasma. Surf. Interfaces. 2023;37:102656. doi: 10.1016/j.surfin.2023.102656. [DOI] [Google Scholar]
  47. Sanbhal N., Saitaer X., Peerzada M., Habboush A., Wang F., Wang L.. One-Step Surface Functionalized Hydrophilic Polypropylene Meshes for Hernia Repair Using Bio-Inspired Polydopamine. Fibers. 2019;7:6. doi: 10.3390/fib7010006. [DOI] [Google Scholar]
  48. Hu W., Lu S., Ma Y., Ren P., Ma X., Zhou N., Zhang T., Ji Z.. Poly­(dopamine)-inspired surface functionalization of polypropylene tissue mesh for prevention of intra-peritoneal adhesion formation. J. Mater. Chem. B. 2017;5:575–585. doi: 10.1039/C6TB02667B. [DOI] [PubMed] [Google Scholar]
  49. Sanbhal N., Mao Y., Sun G., Li Y., Peerzada M., Wang L.. Preparation and Characterization of Antibacterial Polypropylene Meshes with Covalently Incorporated β-Cyclodextrins and Captured Antimicrobial Agent for Hernia Repair. Polymers. 2018;10:58. doi: 10.3390/polym10010058. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Grant D. N., Benson J., Cozad M. J., Whelove O. E., Bachman S. L., Ramshaw B. J., Grant D. A., Grant S. A.. Conjugation of gold nanoparticles to polypropylene mesh for enhanced biocompatibility. J. Mater. Sci. Mater. Med. 2011;22:2803–2812. doi: 10.1007/s10856-011-4449-6. [DOI] [PubMed] [Google Scholar]
  51. Lanzalaco S., Weis C., Traeger K. A., Turon P., Alemán C., Armelin E.. Mechanical Properties of Smart Polypropylene Meshes: Effects of Mesh Architecture, Plasma Treatment, Thermosensitive Coating, and Sterilization Process. ACS Biomater. Sci. Eng. 2023;9:3699–3711. doi: 10.1021/acsbiomaterials.3c00311. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Jiang L., Qin N., Gu S., Zhu W., Wang C., Chen Y.. Rational design of dual-functional surfaces on polypropylene with antifouling and antibacterial performances via a micropatterning strategy. J. Mater. Chem. B. 2022;10:3759–3769. doi: 10.1039/D1TB02778F. [DOI] [PubMed] [Google Scholar]
  53. Farhan T., Huck W. T. S.. Synthesis of patterned polymer brushes from flexible polymeric films. Eur. Polym. J. 2004;40:1599–1604. doi: 10.1016/j.eurpolymj.2004.05.001. [DOI] [Google Scholar]
  54. Zeng Y., Xie L., Chi F., Liu D., Wu H., Pan N., Sun G.. Controlled Growth of Ultra-Thick Polymer Brushes via Surface-Initiated Atom Transfer Radical Polymerization with Active Polymers as Initiators. Macromol. Rapid Commun. 2019;40:1900078. doi: 10.1002/marc.201900078. [DOI] [PubMed] [Google Scholar]
  55. Iscen A., Forero-Martinez N. C., Valsson O., Kremer K.. Acrylic Paints: An Atomistic View of Polymer Structure and Effects of Environmental Pollutants. J. Phys. Chem. B. 2021;125:10854–10865. doi: 10.1021/acs.jpcb.1c05188. [DOI] [PMC free article] [PubMed] [Google Scholar]
  56. Chen M.-A., Li H.-Z., Zhang X.-M.. Improvement of shear strength of aluminium-polypropylene lap joints by grafting maleic anhydride onto polypropylene. Int. J. Adhes. Adhes. 2007;27:175–187. doi: 10.1016/j.ijadhadh.2006.01.008. [DOI] [Google Scholar]
  57. Chen J., Du K., Chen X., Li Y., Huang J., Wu Y., Yang C., Xia X.. Influence of surface microstructure on bonding strength of modified polypropylene/aluminum alloy direct adhesion. Appl. Surf. Sci. 2019;489:392–402. doi: 10.1016/j.apsusc.2019.05.270. [DOI] [Google Scholar]
  58. Liang C.-S., Lv Z.-F., Bo Y., Cui J.-Y., Xu S.-A.. Effect of modified polypropylene on the interfacial bonding of polymer-aluminum laminated films. Mater. Des. 2015;81:141–148. doi: 10.1016/j.matdes.2015.05.021. [DOI] [Google Scholar]

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