Polymers are here to stay, but cellulose could shape packaging's next chapter: Prof MM Sharma

Packaging sustainability discussions must remain grounded in science, practicality and lifecycle thinking, according to Prof MM Sharma, Padma Vibhushan awardee and former director of the Institute of Chemical Technology (ICT).

Addressing delegates as chief guest at Respack 2026, Sharma delivered a strong defence of polymers while simultaneously calling for greater innovation in recycling technologies and renewable cellulose-based packaging materials.

His central message was straightforward. "Packaging without plastic is not possible."

The indispensable role of plastics

Using everyday examples, Sharma challenged the notion that plastics can simply be replaced by alternative materials. From toothpaste tubes and milk pouches to bottled water and edible oils, he argued that polymers remain essential because of their performance, efficiency and affordability. "When we used to use glass bottles, how much energy went into that?" he asked. Sharma pointed to India's success in PET bottle recycling and the broader role polymers have played in improving hygiene, food preservation and consumer safety.

He also highlighted the country's transformation from producing a few thousand tonnes of LDPE decades ago to operating world-scale petrochemical facilities today.

Recycling must be expanded

While defending polymers, Sharma acknowledged the industry's responsibility to improve waste management outcomes. Referencing Prof S Sivaram's earlier remarks on recycling, Sharma suggested that technologies such as pyrolysis deserve greater attention. "If nothing else, at least we should start pyrolysing and getting rid of the bad ones."

According to Sharma, sectors such as paints, where packaging collection systems are more concentrated and organised, offer practical opportunities for large-scale recycling initiatives.

He also highlighted expanded polystyrene (EPS) as an example of a material that remains difficult to replace but can be recycled through depolymerisation technologies that recover styrene monomer.

Challenging misconceptions

Sharma also criticised what he described as misinformation surrounding plastics. Recalling earlier debates around PET bottles, he questioned claims that associated PET with endocrine-disrupting chemicals.

"There is no bisphenol A in PET. Not even a shadow of it." He argued that sustainability discussions should be based on scientific evidence rather than perception-driven narratives.

Looking beyond fossil resources

The most forward-looking section of Sharma's speech focused on renewable feedstocks and cellulose-based materials. He argued that while bio-based polyethylene derived from ethanol is unlikely to be economically viable at large scale, India possesses an abundant and underutilised resource in agricultural waste. "Agro-waste will always be there. As long as there is food, there is agro-waste."

Sharma identified bagasse as a particularly promising feedstock.

India's sugar industry generates millions of tonnes of bagasse annually, much of which could be converted into cellulose, hemicellulose and lignin for value-added applications.

A return to cellulose

According to Sharma, the packaging industry should revisit cellulose-derived materials that once played a major role in manufacturing. "Time has come to go back to cellulose-based plastics."

He highlighted cellulose acetate, carboxymethyl cellulose (CMC) and other cellulose derivatives as renewable and potentially biodegradable alternatives for specific packaging applications.

Far from being experimental materials, Sharma noted that cellulose-based plastics have a long industrial history and remain widely used in various sectors today. "I would urge the industry to re-look at cellulose as a starting material for packaging."

Reducing food wastage

Sharma also stressed the need for advanced barrier films that can help reduce food losses. India remains one of the world's largest producers of fruits and vegetables, yet significant quantities are lost due to inadequate preservation and logistics systems. He argued that extending shelf life may represent one of packaging's most important sustainability contributions, particularly in a country where food wastage remains a major challenge.

Science, not sentiment

Throughout his address, Sharma maintained that sustainability should be approached through scientific assessment of trade-offs rather than simplistic material comparisons.

Glass, paper and natural fibres all have environmental costs, he argued, and many alternative materials continue to rely on polymer layers to achieve necessary performance characteristics. "Polymers are there to stay. They are energy efficient."

His conclusion reflected a balanced vision for the future: continued use of high-performance polymers, accelerated recycling, improved waste management and greater exploration of renewable cellulose-based materials. "There are problems and they are amenable to be solved in one way or another."

For Sharma, the future of packaging is not about abandoning polymers. It is about improving them, recovering them and complementing them with renewable solutions where they make technical and economic sense.